Home » Public Forums » GMCnet » Disc Brake Park Brake Again
| Disc Brake Park Brake Again [message #240937] |
Sun, 23 February 2014 06:25  |
cadelec
Messages: 303
Registered: September 2011
Location: Brisbane Australia
Karma: 1
|
Senior Member |
|
|
Well i am finally getting around to trying to jump through the hoops to get this unit registered in australia
i have 80 mm caddy front calipers on all rear wheels on caddy backing plates
no hand brake cables at all
hand brake lever has been removed
my engineer has Given me this below concerning parking brake
Park brake - According to 2nd edition ADRs the park brake must be a 'mechanical frictional' type brake. Nothing really we didn't already know. I have found these on the net http://www.bdub.net/branscombe/ do a kit. This will require a 'park brake test' to determine if the parking brake is capable of maintaining the vehicle stationery on a 20deg slope. There is a 19 deg street in Hamilton that we can use (Quarry st). Code LG2 will need to be applied to verify both the installation and function.
my first thoughts were to replace the exiting 80 mm calipers with
cadillac park eldo park brake calipers on all 4 wheels and actuate this using a linear actuator
but i thought i would ask for opinions from the group
also as my coach is ex bobby moores some of you may have abit more knowledge of what he has done or point me to wher anything that he did was documented.
Trevor
Brisbane Australia
Siesta Koala 76 Edgemont (old Bobby Moores)
71 Cadillac Eldo Convert
58 Cadillac Eldorado Brougham Project
|
|
|
|
| Re: Disc Brake Park Brake Again [message #240940 is a reply to message #240937] |
Sun, 23 February 2014 07:20  |
kerry pinkerton
Messages: 2565
Registered: July 2012
Location: Harvest, Al
Karma: 15
|
Senior Member |
|
|
Trevor, are you allowed to have a ratcheting lever? If so, you might be able to us use a pair of Albert's Kelsey Hayes caliper. They use a cam screw to actuate the parking fuction and will hold better than any other type of caliper. The problem is, as noted in Albert's white paper, is the distance of travel required to fully lock them down is more than the stock handle can product.
I'd think you could adapt a ratcheting type of handle (think a cable 'Come-a-long' type thing) to accomplish this.
Kerry Pinkerton - North Alabama
Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L
|
|
|
|
| Re: Disc Brake Park Brake Again [message #241010 is a reply to message #240940] |
Sun, 23 February 2014 15:16 |
cadelec
Messages: 303
Registered: September 2011
Location: Brisbane Australia
Karma: 1
|
Senior Member |
|
|
i just looked up the regulations and this is what it says
A parking braking system which has to be actuated several times before it attains the prescribed performance is admissible
excuse my ignorance but admissible = allowable Correct???
| Kerry Pinkerton wrote on Sun, 23 February 2014 07:20 |
Trevor, are you allowed to have a ratcheting lever? If so, you might be able to us use a pair of Albert's Kelsey Hayes caliper. They use a cam screw to actuate the parking fuction and will hold better than any other type of caliper. The problem is, as noted in Albert's white paper, is the distance of travel required to fully lock them down is more than the stock handle can product.
I'd think you could adapt a ratcheting type of handle (think a cable 'Come-a-long' type thing) to accomplish this.
|
Trevor
Brisbane Australia
Siesta Koala 76 Edgemont (old Bobby Moores)
71 Cadillac Eldo Convert
58 Cadillac Eldorado Brougham Project
|
|
|
|
|
|
|
|
| Re: Disc Brake Park Brake Again [message #241083 is a reply to message #241026] |
Sun, 23 February 2014 23:44 |
kerry pinkerton
Messages: 2565
Registered: July 2012
Location: Harvest, Al
Karma: 15
|
Senior Member |
|
|
| cadelec wrote on Sun, 23 February 2014 17:12 |
...cadillac eldorado rear calipers should be a direct bolt up easiest and cheapest solution
but due to the 20 percent gradient requirement i think i will need to install on all four rear wheels my concern is if i change to these i will reduce the piston sizes down to 64 mm on all four rear wheels and upset the braking characteristics that seem to work well ...
|
At the Branson GMCMI rally, Albert gave a presentation about theoretical braking capacities of various 'systems'...although he did not have numbers on the stock coach which seems a major omission in any comparison of how one system or the other works better than stock. All the aftermarket systems out perform a stock coach. He agreed but I haven't seen updated numbers if he's done them.
I'm not an engineer and there are folks involved with this stuff who are and who can pepper you with all sorts of math and stuff that I don't even comprehend. I'm just a shade tree fabricator and car guy all my life. HOWEVER, seems to me that the most braking we can EVER have is the ability to brake until we reach the limit of adhesion of our tires on smooth dry pavement. Once we've got enough brakes to lock the tires, bigger, better, badder, more expensive, etc brakes aren't going to stop you any faster. I'm not suggesting you'll stop faster by sliding the tires...of course you will not...what I'm saying is that if you can slide the tires in a worst case scenario, it seems to me you've got all the brakes you can USE. There may be exceptions to my thinking if you're going to road race your GMC on mountain roads but I'm thinking for most of us that's probably not much of a concern.
If I understand the principle correctly (and being a non-engineer it's quite possible), the idea is to have your system balanced so that all 6 wheels brake the same and perhaps have the rears lock up just before the fronts. When Ken Henderson and I tested my Manny brakes, we found a gravel road and I stomped the brakes while Ken watched. The mid axle slid first and the rear axle was almost sliding. Prior to the Manny Brake systems reaction arm type thing, the rears would have slid almost immediately.
I have not tried to slide my tires on pavement because I have no desire to flat spot them. However, even though the Manny Brake system uses the smallest calipers/rotors of the available kits and therefore has the lowest theoretical braking capacity, I'm confident I could lock them up if for some reason I wanted to. I can make them moan and have leg and pedal left. Again, I'm not going to ruin my new tires to prove a point to someone. No one has convinced me that bigger brakes will stop me faster although I'm certainly willing to listen.
I guess what I'm saying is that you might not have a problem with slightly smaller calipers, you could use a proportioning valve to balance the fronts and rears. You're going to have to do something and it's either a Kelsey Hayes caliper or some of the large GM calipers like Rob posted. The KH calipers have MUCH more gripping capability parking brake because of the ball screw mechanism.
Finally, given that current model cars apparently have non-mechanical parking brakes, it might be worth running that fact up the flagpole with the authorities. I don't know how the Aussie bureaucrats work but over here, outdated rules and paperwork is not unusual at all. SOMETIMES, you might get hold of someone reasonable that can make a decision.
Kerry Pinkerton - North Alabama
Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L
|
|
|
|
| Re: Disc Brake Park Brake Again [message #241084 is a reply to message #241083] |
Mon, 24 February 2014 00:05 |
cadelec
Messages: 303
Registered: September 2011
Location: Brisbane Australia
Karma: 1
|
Senior Member |
|
|
thanks kerry
i have see alberts presentation and the hayes calipers are certainly better than the caddy ones. it will all come done to price versus performance verses ease of implimenting
i am waiting for albert to get back to me with pricing for his system
Trevor
Brisbane Australia
Siesta Koala 76 Edgemont (old Bobby Moores)
71 Cadillac Eldo Convert
58 Cadillac Eldorado Brougham Project
|
|
|
|
| Re: [GMCnet] Disc Brake Park Brake Again [message #241085 is a reply to message #241083] |
Mon, 24 February 2014 00:06 |
 |
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
|
Senior Member |
|
|
Kerry,
One of the problems that exist for those of us that have GMC's in Australia is that any modification to a vehicle need to be
approved by an engineer with a degree blessed by the state he works in to give those approvals. If someone installs a braking system
that is not OEM without that approval their butt is in the breeze if an accident occurs and if the state or insurance company
decides to investigate and discovers that the brakes have been modified.
People will now say; "how are they going to be able to tell that an aftermarket system such as the reaction arm system wasn't
installed by Detroit and the answer is simple; does that system look like something that Detroit would have installed - if anyone
says yes I have a bridge I'd like to sell them!
However, the Caddy disk brake conversion uses parts that were made by Detroit and therefore looks like something that came from
Detroit because it bloody well did!
You are 100% correct the KH calipers with the ball ramp actuation system is superior the Caddy calipers but once again the mounting
brackets don't look like something Detroit would have made.
I have a brass combination valve on Double Trouble (front disks / middle disks / rear drums) I got from JimB and it works just fine
it sends pressure to the rear wheel cylinders (calipers) before the front calipers. See the description under the photo below.
http://www.gmcmhphotos.com/photos/random-photos/p37696-combination-valve-cros.html
Regards,
Rob M.
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org [mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Kerry Pinkerton
Sent: Monday, February 24, 2014 4:44 PM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] Disc Brake Park Brake Again
At the Branson GMCMI rally, Albert gave a presentation about theoretical braking capacities of various 'systems'...although he did
not have numbers on the stock coach which seems a major omission in any comparison of how one system or the other works better than
stock. All the aftermarket systems out perform a stock coach. He agreed but I haven't seen updated numbers if he's done them.
I'm not an engineer and there are folks involved with this stuff who are and who can pepper you with all sorts of math and stuff
that I don't even comprehend. I'm just a shade tree fabricator and car guy all my life. HOWEVER, seems to me that the most braking
we can EVER have is the ability to brake until we reach the limit of adhesion of our tires on smooth dry pavement. Once we've got
enough brakes to lock the tires, bigger, better, badder, more expensive, etc brakes aren't going to stop you any faster. I'm not
suggesting you'll stop faster by sliding the tires...of course you will not...what I'm saying is that if you can slide the tires in
a worst case scenario, it seems to me you've got all the brakes you can USE. There may be exceptions to my thinking if you're going
to road race your GMC on mountain roads but I'm thinking for most of us that's probably not much of a concern.
If I understand the principle correctly (and being a non-engineer it's quite possible), the idea is to have your system balanced so
that all 6 wheels brake the same and perhaps have the rears lock up just before the fronts. When Ken Henderson and I tested my
Manny brakes, we found a gravel road and I stomped the brakes while Ken watched. The mid axle slid first and the rear axle was
almost sliding. Prior to the Manny Brake systems reaction arm type thing, the rears would have slid almost immediately.
I have not tried to slide my tires on pavement because I have no desire to flat spot them. However, even though the Manny Brake
system uses the smallest calipers/rotors of the available kits and therefore has the lowest theoretical braking capacity, I'm
confident I could lock them up if for some reason I wanted to. I can make them moan and have leg and pedal left. Again, I'm not
going to ruin my new tires to prove a point to someone. No one has convinced me that bigger brakes will stop me faster although I'm
certainly willing to listen.
I guess what I'm saying is that you might not have a problem with slightly smaller calipers, you could use a proportioning valve to
balance the fronts and rears. You're going to have to do something and it's either a Kelsey Hayes caliper or some of the large GM
calipers like Rob posted. The KH calipers have MUCH more gripping capability parking brake because of the ball screw mechanism.
Finally, given that current model cars apparently have non-mechanical parking brakes, it might be worth running that fact up the
flagpole with the authorities. I don't know how the Aussie bureaucrats work but over here, outdated rules and paperwork is not
unusual at all. SOMETIMES, you might get hold of someone reasonable that can make a decision.
Kerry
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
|
|
|
|
| Re: [GMCnet] Disc Brake Park Brake Again [message #241092 is a reply to message #240937] |
Mon, 24 February 2014 05:11 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
Trevor,
Are you saying your coach does not have a linear actuator operating
Cadillac parking brake calipers on the rear wheels? That's the
configuration in which Bobby left it. The linear actuator was actually an
electric seat motor and gearing. Bobby swore by it, but perhaps a SO
didn't share his love of it.
I don't know that the installation was ever documented, but several people
copied it. In fact, Stick Miller's coach is one of the "descendants",
though I think it has a true linear actuator. Stick, have you ever tried
it? Or can't you find the switch among all the unknowns? :-)
Trevor, would your engineer consider the linear actuator to still be
"mechanical"? Seems to me it should be, one never knows.
Ken H.
On Sun, Feb 23, 2014 at 7:25 AM, Trevor Pordage wrote:
>
>
> Well i am finally getting around to trying to jump through the hoops to
> get this unit registered in australia
>
>
> i have 80 mm caddy front calipers on all rear wheels on caddy backing
> plates
> no hand brake cables at all
> hand brake lever has been removed
>
> my engineer has Given me this below concerning parking brake
>
> Park brake - According to 2nd edition ADRs the park brake must be a
> 'mechanical frictional' type brake. Nothing really we didn't already
> know. I have found these on the net http://www.bdub.net/branscombe/ do a
> kit. This will require a 'park brake test' to determine if the parking
> brake is capable of maintaining the vehicle stationery on a 20deg slope.
> There is a 19 deg street in Hamilton that we can use (Quarry st). Code
> LG2 will need to be applied to verify both the installation and function.
>
>
> my first thoughts were to replace the exiting 80 mm calipers with
> cadillac park eldo park brake calipers on all 4 wheels and actuate this
> using a linear actuator
>
> but i thought i would ask for opinions from the group
>
> also as my coach is ex bobby moores some of you may have abit more
> knowledge of what he has done or point me to wher anything that he did
> was documented.
>
> --
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
|
|
|
|
| Re: [GMCnet] Disc Brake Park Brake Again [message #241097 is a reply to message #241092] |
Mon, 24 February 2014 06:45 |
cadelec
Messages: 303
Registered: September 2011
Location: Brisbane Australia
Karma: 1
|
Senior Member |
|
|
Yes ken
both rear calipers are the same Link to photo no mechanical lever on the caliper and the seat actuator that would have been under the coach is completely missing
I think i am about to change engineers and find one with a bit more experience as the current bloke is asking too many questions with the department of transport. there are a lot of grey areas and i need an engineer who is not afraid to veer over to the darker side. I just want these engineers to have a bit of common sense instead of trying to interprete the rules to the exact way it is written.
i have had one engineer say that an electric actuator will be ok
but he is causing me concerns in the overhang area .
the over hang rule states that the distance between the center of the rear axle group to the rear of the coach can not be more than 60 per cent of the distance of the center of the front wheel to the center of the rear axle group (half way between the center of the rear wheels).
if you measure this to the rear of the stop/indicator lens we are overlength by 26mm so i either have to move the wheels back or french the taillights. both things i dont want to do
i will just have to find an engineer who will listen to reason.
| Ken Henderson wrote on Mon, 24 February 2014 05:11 |
Trevor,
Are you saying your coach does not have a linear actuator operating
Cadillac parking brake calipers on the rear wheels? That's the
configuration in which Bobby left it. The linear actuator was actually an
electric seat motor and gearing. Bobby swore by it, but perhaps a SO
didn't share his love of it.
I don't know that the installation was ever documented, but several people
copied it. In fact, Stick Miller's coach is one of the "descendants",
though I think it has a true linear actuator. Stick, have you ever tried
it? Or can't you find the switch among all the unknowns? 
Trevor, would your engineer consider the linear actuator to still be
"mechanical"? Seems to me it should be, one never knows.
Ken H.
On Sun, Feb 23, 2014 at 7:25 AM, Trevor Pordage wrote:
>
>
> Well i am finally getting around to trying to jump through the hoops to
> get this unit registered in australia
>
>
> i have 80 mm caddy front calipers on all rear wheels on caddy backing
> plates
> no hand brake cables at all
> hand brake lever has been removed
>
> my engineer has Given me this below concerning parking brake
>
> Park brake - According to 2nd edition ADRs the park brake must be a
> 'mechanical frictional' type brake. Nothing really we didn't already
> know. I have found these on the net http://www.bdub.net/branscombe/ do a
> kit. This will require a 'park brake test' to determine if the parking
> brake is capable of maintaining the vehicle stationery on a 20deg slope.
> There is a 19 deg street in Hamilton that we can use (Quarry st). Code
> LG2 will need to be applied to verify both the installation and function.
>
>
> my first thoughts were to replace the exiting 80 mm calipers with
> cadillac park eldo park brake calipers on all 4 wheels and actuate this
> using a linear actuator
>
> but i thought i would ask for opinions from the group
>
> also as my coach is ex bobby moores some of you may have abit more
> knowledge of what he has done or point me to wher anything that he did
> was documented.
>
> --
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
Trevor
Brisbane Australia
Siesta Koala 76 Edgemont (old Bobby Moores)
71 Cadillac Eldo Convert
58 Cadillac Eldorado Brougham Project
|
|
|
|
| Re: [GMCnet] Disc Brake Park Brake Again [message #241122 is a reply to message #241092] |
Mon, 24 February 2014 11:15 |
78 Barbi
Messages: 80
Registered: August 2004
Location: Tiverton, Ontario , Canad...
Karma: -1
|
Member |
|
|
Ken H. refers to Bobby Moores coach .
Ken,
If you remember the incident at the 2006 Barrian Springs, MI rally , I asked the audience if anyone had a set of disc park brakes that actually worked , alas Bobby Moore shot up his hand and said he had a system that worked flawlessly , a bit later when I went to his coach to do some tensiometer readings on his cables , he remembered he had removed the Caddy callipers because they were dragging .
I'm somewhat puzzled about the 20 degree slope requirement quote below ; are you absolutely sure that it's 20 degrees and NOT a 20 % slope ? The reason I ask this is thus …….. At a 20 degree slope your 12,000 lb. GMC has a forward force component of 4,104 lbs. parallel with the slope.
The weight on the two rearmost wheels is approx. 2,000 lbs. per wheel ( static ) on level ground , on a 20 degree slope the wheel weight would be slightly less than this. The general "rule of thumb " is that a tire will break friction with the pavement at 0.8 of the wheel weight , ie. 2,000 lb. times 0.8 equals 1,600 lb. per wheel of holding force.
The Caddy 2.5” PB caliper would be useless under these conditions as would the Kelsey Hayes , Why, I even doubt that Tom’s magic drums would work ! This simply means that even if you succeeded in welding the caliper and disc together on the rearmost wheel set, your coach would slide down the hill quite nicely with the rear wheels locked up.
The presentation at Branson that I gave was a draft ( or worse ! ) , it was cleaned up and edited once I returned home and shows the OEM coach braking data on our website AND on the GMCMI tech site.
The main reason the Kelsey Hayes caliper mount is not a “ casting” a Detroit originally designed , was ; I had no control over quality assurance of the casting , I did however have control over the welded steel assembly , ya ! it looks a bit funny but it was tested to over double to whatever stress it was ever to encounter.
Trevor; we need more data and clarification as to your needs, hopefully we can be of some assistance, check with Rob & Peter in the “ land down under” to see what they have done .
Cheers …….Albert
The 23 foot Birchaven , Tiverton, ON, CAN
[Updated on: Mon, 24 February 2014 11:57] Report message to a moderator |
|
|
|
| Re: [GMCnet] Disc Brake Park Brake Again [message #241138 is a reply to message #241122] |
Mon, 24 February 2014 14:05 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
Albert,
I had (have) forgotten the exchange with Bobby. I guess he or a SO decided
the actuator was excess baggage too.
If the rules have indeed changed, what do you think of a linear
actuator(s)? I know you're tired of developing new stuff, but there seem
to be some cost & simplicity advantages. I know that immediately after
Branson 2013, Alex Ferrara installed one which he ordered from Branson. He
found an appropriate one with internal tension limiting, which should have
solved one of the problems I was concerned about. But, I've heard very
little from him since an initial report.
Ken H.
On Mon, Feb 24, 2014 at 12:15 PM, Albert&Sheila Branscombe wrote:
>
>
> Ken H. refers to Bobby Moores coach .
>
> Ken,
> If you remember the incident at the 2006 Branson rally , I asked the
> audience if anyone had a set of disc park brakes that actually worked ,alas Bobby Moore shot up his hand and said he had a system that worked
> flawlessly , a bit later when I went to his coach to do some tensiometerreadings on his cables,he remembered he had removed the Caddy callipers because they were dragging.
>
> I'm somewhat puzzled about the 20 degree slope requirement quote below ; are you absolutely sure that it's 20 degrees and NOT a 20 % slope? The reason I ask this is thus …….. At a 20 degree slope your
> 12,000 lb. GMC has a forward force component of 4,104 lbs. parallel with
> the slope.
>
> The weight on the two rearmost wheels is approx. 2,000 lbs. per wheel (
> static ) on level ground , on a 20 degree slope the wheel weight would
> be slightly less than this. The general "rule of thumb " is that a tire
> will break friction with the pavement at 0.8 of the wheel weight , ie.
> 2,000 lb. times 0.8 equals 1,600 lb. per wheel of holding force.
>
> The Caddy 2.5” PB caliper would be useless under these conditions as
> would the Kelsey Hayes , Why, I even doubt that Tom’s magic drums
> would work ! This simply means that even if you succeeded in welding the
> caliper and disc together on the rearmost wheel set, your coach would slide
> down the hill quite nicely with the rear wheels locked up.
>
> The presentation at Branson that I gave was a draft ( or worse ! ) , it
> was cleaned up and edited once I returned home and shows the OEM coach
> braking data on our website AND on the GMCMI tech site.
>
> The main reason the Kelsey Hayes caliper mount is not a “
> casting” a Detroit originally designed , was ; I had no control
> over quality assurance of the casting , I did however have control over
> the welded steel assembly , ya ! it looks a bit funny but it was tested
> to over double to whatever stress it was ever to encounter.
>
> Trevor; we need more data and clarification as to your needs, hopefully
> we can be of some assistance, check with Rob & Peter in the “ land
> down under” to see what they have done .
>
> Cheers …….Albert
> The 23 foot Birchaven , Tiverton, ON, CAN
>
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
|
|
|
|
| Re: [GMCnet] Disc Brake Park Brake Again [message #241153 is a reply to message #241138] |
Mon, 24 February 2014 16:20 |
78 Barbi
Messages: 80
Registered: August 2004
Location: Tiverton, Ontario , Canad...
Karma: -1
|
Member |
|
|
Ken Henderson writes : What do you think of a linear
actuator(s)? I know you're tired of developing new stuff..........
Hey Ken !
Yes our days of R & D are quickly drawing to a close . Our first actuator was in fact a microprocessor controlled current limiting linear actuator ALL $750.00 worth of it , fun to build and still working but totally impractical from a cost / benefit standpoint.
I've always been slightly nervous about linear actuators in that some guy buys a big 1,000 pounder and bends the crap out of his levers inside his brake drums . If they can be current controlled or clutch controlled , I see no problem with them . I recommended the E-STOPP unit to John Sharpe when he installed our Kelsey Hayes system due to the fact he had the Electro Level II and consequently no ready air supply for our booster.
I use the air boost for a number of reasons , It can't overstress the components, it will cycle in less than 2 seconds ( you know what that means ! ) , no holes to drill , simply bolt the sucker into place and it's relatively inexpensive AND it provides distance enhancement on the cable set. .
I wrote Trevor and explained that percent grade and degrees slope are two entirely different things , As you can appreciate ; individual owners can do things with their braking system that I cannot do as a vendor.
Cheers.......Albert
78 Barbi, The 23 foot Birchaven
Tiverton, ON , CAN
|
|
|
|
| Re: [GMCnet] Disc Brake Park Brake Again [message #241171 is a reply to message #241122] |
Mon, 24 February 2014 17:06 |
|
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
|
Senior Member |
|
|
Albert,
The Blue Streak has 100% standard OEM brakes, front and rear; however, when I bought The Blue Streak I received an uninstalled TSM
rear disk brake setup with it which I THOUGHT was great!
I then had conversations with Mark Bennett who is REALLY cluey on Australian Design Rules for vehicles and he noted that to be safe
I'd have to have the setup reviewed and certified by an engineer. If I modified them, had an accident that was investigated and it
was discovered that I had done so WITHOUT certification I would be in BIG trouble!
Somewhere along the line I had a chat with Emery Stora who noted that he (or someone else) had suffered a rear Caddy caliper failure
because the mechanism that released the pads when the parking brake was released stuck. IIRC Emery (or somebody else) noted that
this was a common problem the Caddy calipers UNLESS they were properly maintained AND used!
I've looked at cross sections of the Caddy caliper parking brake mechanism and it appears that they use an Acme thread kinda device
to push the pads together and if that device is not lubricated, gets contaminated, or rusts it jams and the pads don't release. I
apologize for the half-assed description of the way the system works. If anyone is REALLY interested click on the link below:
http://www.pirate4x4.com/forum/general-4x4-discussion/772253-cadillac-caliper-rear-e-brake-adjustment.html
I have seen your presentation on the Kelsey Hayes caliper and the system it uses to actuate the parking brake is head and shoulders
above the Caddy caliper. It uses what I call a ball ramp system like the one used to actuate Harley-Davidson clutches:
http://bakerdrivetrain.com/9-plate-ball-ramp-big-dog-2005-2010
There is no way that system can get stuck and drag the pads.
Regards,
Rob M.
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
-----Original Message-----
From: Albert&Sheila Branscombe
Ken H. refers to Bobby Moores coach .
Ken,
If you remember the incident at the 2006 Branson rally , I asked the audience if anyone had a set of disc park brakes that actually
worked , alas Bobby Moore shot up his hand and said he had a system that worked flawlessly , a bit later when I went to his coach to
do some tensiometer readings on his cables , he remembered he had removed the Caddy callipers because they were dragging .
I'm somewhat puzzled about the 20 degree slope requirement quote below ; are you absolutely sure that it's 20 degrees and NOT a 20
% slope ? The reason I ask this is thus …….. At a 20 degree slope your 12,000 lb. GMC has a forward force component of
4,104 lbs. parallel with the slope.
The weight on the two rearmost wheels is approx. 2,000 lbs. per wheel ( static ) on level ground , on a 20 degree slope the wheel
weight would be slightly less than this. The general "rule of thumb " is that a tire will break friction with the pavement at
0.8 of the wheel weight , ie. 2,000 lb. times 0.8 equals 1,600 lb. per wheel of holding force.
The Caddy 2.5” PB caliper would be useless under these conditions as would the Kelsey Hayes , Why, I even doubt that
Tom’s magic drums would work ! This simply means that even if you succeeded in welding the caliper and disc together on the
rearmost wheel set, your coach would slide down the hill quite nicely with the rear wheels locked up.
The presentation at Branson that I gave was a draft ( or worse ! ) , it was cleaned up and edited once I returned home and shows the
OEM coach braking data on our website AND on the GMCMI tech site.
The main reason the Kelsey Hayes caliper mount is not a “ casting” a Detroit originally designed , was ; I had no
control over quality assurance of the casting , I did however have control over the welded steel assembly , ya ! it looks a bit
funny but it was tested to over double to whatever stress it was ever to encounter.
Trevor; we need more data and clarification as to your needs, hopefully we can be of some assistance, check with Rob & Peter in
the “ land down under” to see what they have done .
Cheers …….Albert
The 23 foot Birchaven , Tiverton, ON, CAN
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
|
|
|
|
| Re: [GMCnet] Disc Brake Park Brake Again [message #241193 is a reply to message #241138] |
Mon, 24 February 2014 18:36 |
sgltrac
Messages: 2797
Registered: April 2011
Karma: 1
|
Senior Member |
|
|
Still waiting for mine Ken 😜
Todd Sullivan
Sully
77 royale
Seattle
> On Feb 24, 2014, at 12:05 PM, Ken Henderson <hend4800@bellsouth.net> wrote:
>
> Albert,
>
> I had (have) forgotten the exchange with Bobby. I guess he or a SO decided
> the actuator was excess baggage too.
>
> If the rules have indeed changed, what do you think of a linear
> actuator(s)? I know you're tired of developing new stuff, but there seem
> to be some cost & simplicity advantages. I know that immediately after
> Branson 2013, Alex Ferrara installed one which he ordered from Branson. He
> found an appropriate one with internal tension limiting, which should have
> solved one of the problems I was concerned about. But, I've heard very
> little from him since an initial report.
>
> Ken H.
>
>
>> On Mon, Feb 24, 2014 at 12:15 PM, Albert&Sheila Branscombe wrote:
>>
>>
>>
>> Ken H. refers to Bobby Moores coach .
>>
>> Ken,
>> If you remember the incident at the 2006 Branson rally , I asked the
>> audience if anyone had a set of disc park brakes that actually worked ,alas Bobby Moore shot up his hand and said he had a system that worked
>> flawlessly , a bit later when I went to his coach to do some tensiometerreadings on his cables,he remembered he had removed the Caddy callipers because they were dragging.
>>
>> I'm somewhat puzzled about the 20 degree slope requirement quote below ; are you absolutely sure that it's 20 degrees and NOT a 20 % slope? The reason I ask this is thus …….. At a 20 degree slope your
>> 12,000 lb. GMC has a forward force component of 4,104 lbs. parallel with
>> the slope.
>>
>> The weight on the two rearmost wheels is approx. 2,000 lbs. per wheel (
>> static ) on level ground , on a 20 degree slope the wheel weight would
>> be slightly less than this. The general "rule of thumb " is that a tire
>> will break friction with the pavement at 0.8 of the wheel weight , ie.
>> 2,000 lb. times 0.8 equals 1,600 lb. per wheel of holding force.
>>
>> The Caddy 2.5” PB caliper would be useless under these conditions as
>> would the Kelsey Hayes , Why, I even doubt that Tom’s magic drums
>> would work ! This simply means that even if you succeeded in welding the
>> caliper and disc together on the rearmost wheel set, your coach would slide
>> down the hill quite nicely with the rear wheels locked up.
>>
>> The presentation at Branson that I gave was a draft ( or worse ! ) , it
>> was cleaned up and edited once I returned home and shows the OEM coach
>> braking data on our website AND on the GMCMI tech site.
>>
>> The main reason the Kelsey Hayes caliper mount is not a “
>> casting” a Detroit originally designed , was ; I had no control
>> over quality assurance of the casting , I did however have control over
>> the welded steel assembly , ya ! it looks a bit funny but it was tested
>> to over double to whatever stress it was ever to encounter.
>>
>> Trevor; we need more data and clarification as to your needs, hopefully
>> we can be of some assistance, check with Rob & Peter in the “ land
>> down under” to see what they have done .
>>
>> Cheers …….Albert
>> The 23 foot Birchaven , Tiverton, ON, CAN
>>
>>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Sully
77 Royale basket case.
Future motorhome land speed record holder(bucket list)
Seattle, Wa.
|
|
|
|
| Re: [GMCnet] Disc Brake Park Brake Again [message #241212 is a reply to message #241193] |
Mon, 24 February 2014 19:25 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
Uh! Oh! -- NOW what have I forgotten???
Ken H.
On Mon, Feb 24, 2014 at 7:36 PM, Todd Sullivan <sgltrac@gmail.com> wrote:
> Still waiting for mine Ken 😜
>
> Todd Sullivan
>
> Sully
> 77 royale
> Seattle
>
> > On Feb 24, 2014, at 12:05 PM, Ken Henderson <hend4800@bellsouth.net>
> wrote:
> >
> > Albert,
> >
> > I had (have) forgotten the exchange with Bobby. I guess he or a SO
> decided
> > the actuator was excess baggage too.
> >
> > If the rules have indeed changed, what do you think of a linear
> > actuator(s)? I know you're tired of developing new stuff, but there
> seem
> > to be some cost & simplicity advantages. I know that immediately after
> > Branson 2013, Alex Ferrara installed one which he ordered from Branson.
> He
> > found an appropriate one with internal tension limiting, which should
> have
> > solved one of the problems I was concerned about. But, I've heard very
> > little from him since an initial report.
> >
> > Ken H.
> >
> >
> >> On Mon, Feb 24, 2014 at 12:15 PM, Albert&Sheila Branscombe wrote:
> >>
> >>
> >>
> >> Ken H. refers to Bobby Moores coach .
> >>
> >> Ken,
> >> If you remember the incident at the 2006 Branson rally , I asked the
> >> audience if anyone had a set of disc park brakes that actually worked ,alas
> Bobby Moore shot up his hand and said he had a system that worked
> >> flawlessly , a bit later when I went to his coach to do some
> tensiometerreadings on his cables,he remembered he had removed the Caddy
> callipers because they were dragging.
> >>
> >> I'm somewhat puzzled about the 20 degree slope requirement quote below;are you absolutely sure that it's 20 degrees and NOT a 20 % slope? The
> reason I ask this is thus …….. At a 20 degree slope your
> >> 12,000 lb. GMC has a forward force component of 4,104 lbs. parallelwith
> >> the slope.
> >>
> >> The weight on the two rearmost wheels is approx. 2,000 lbs. per wheel (
> >> static ) on level ground , on a 20 degree slope the wheel weight would
> >> be slightly less than this. The general "rule of thumb " is that a
> tire
> >> will break friction with the pavement at 0.8 of the wheel weight , ie.
> >> 2,000 lb. times 0.8 equals 1,600 lb. per wheel of holding force.
> >>
> >> The Caddy 2.5” PB caliper would be useless under these conditions
> as
> >> would the Kelsey Hayes , Why, I even doubt that Tom’s magic drums
> >> would work ! This simply means that even if you succeeded in welding
> the
> >> caliper and disc together on the rearmost wheel set, your coach would
> slide
> >> down the hill quite nicely with the rear wheels locked up.
> >>
> >> The presentation at Branson that I gave was a draft ( or worse ! ) , it
> >> was cleaned up and edited once I returned home and shows the OEM coach
> >> braking data on our website AND on the GMCMI tech site.
> >>
> >> The main reason the Kelsey Hayes caliper mount is not a “
> >> casting” a Detroit originally designed , was ; I had no control
> >> over quality assurance of the casting , I did however have control
> over
> >> the welded steel assembly , ya ! it looks a bit funny but it was tested
> >> to over double to whatever stress it was ever to encounter.
> >>
> >> Trevor; we need more data and clarification as to your needs, hopefully
> >> we can be of some assistance, check with Rob & Peter in the “
> land
> >> down under” to see what they have done .
> >>
> >> Cheers …….Albert
> >> The 23 foot Birchaven , Tiverton, ON, CAN
> >>
> >>
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
|
|
|
|
| Re: [GMCnet] Disc Brake Park Brake Again [message #241231 is a reply to message #241212] |
Mon, 24 February 2014 20:06 |
sgltrac
Messages: 2797
Registered: April 2011
Karma: 1
|
Senior Member |
|
|
You were going to hook a brother up with parts similar to your system in your coach. Remember the hill after the ferry boat???? ;)
Todd Sullivan
Sully
77 royale
Seattle
> On Feb 24, 2014, at 5:25 PM, Ken Henderson <hend4800@bellsouth.net> wrote:
>
> Uh! Oh! -- NOW what have I forgotten???
>
> Ken H.
>
>
>> On Mon, Feb 24, 2014 at 7:36 PM, Todd Sullivan <sgltrac@gmail.com> wrote:
>>
>> Still waiting for mine Ken 😜
>>
>> Todd Sullivan
>>
>> Sully
>> 77 royale
>> Seattle
>>
>>>> On Feb 24, 2014, at 12:05 PM, Ken Henderson <hend4800@bellsouth.net>
>>> wrote:
>>>
>>> Albert,
>>>
>>> I had (have) forgotten the exchange with Bobby. I guess he or a SO
>> decided
>>> the actuator was excess baggage too.
>>>
>>> If the rules have indeed changed, what do you think of a linear
>>> actuator(s)? I know you're tired of developing new stuff, but there
>> seem
>>> to be some cost & simplicity advantages. I know that immediately after
>>> Branson 2013, Alex Ferrara installed one which he ordered from Branson.
>> He
>>> found an appropriate one with internal tension limiting, which should
>> have
>>> solved one of the problems I was concerned about. But, I've heard very
>>> little from him since an initial report.
>>>
>>> Ken H.
>>>
>>>
>>>> On Mon, Feb 24, 2014 at 12:15 PM, Albert&Sheila Branscombe wrote:
>>>>
>>>>
>>>>
>>>> Ken H. refers to Bobby Moores coach .
>>>>
>>>> Ken,
>>>> If you remember the incident at the 2006 Branson rally , I asked the
>>>> audience if anyone had a set of disc park brakes that actually worked ,alas
>> Bobby Moore shot up his hand and said he had a system that worked
>>>> flawlessly , a bit later when I went to his coach to do some
>> tensiometerreadings on his cables,he remembered he had removed the Caddy
>> callipers because they were dragging.
>>>>
>>>> I'm somewhat puzzled about the 20 degree slope requirement quote below;are you absolutely sure that it's 20 degrees and NOT a 20 % slope? The
>> reason I ask this is thus …….. At a 20 degree slope your
>>>> 12,000 lb. GMC has a forward force component of 4,104 lbs. parallelwith
>>>> the slope.
>>>>
>>>> The weight on the two rearmost wheels is approx. 2,000 lbs. per wheel (
>>>> static ) on level ground , on a 20 degree slope the wheel weight would
>>>> be slightly less than this. The general "rule of thumb " is that a
>> tire
>>>> will break friction with the pavement at 0.8 of the wheel weight , ie.
>>>> 2,000 lb. times 0.8 equals 1,600 lb. per wheel of holding force.
>>>>
>>>> The Caddy 2.5” PB caliper would be useless under these conditions
>> as
>>>> would the Kelsey Hayes , Why, I even doubt that Tom’s magic drums
>>>> would work ! This simply means that even if you succeeded in welding
>> the
>>>> caliper and disc together on the rearmost wheel set, your coach would
>> slide
>>>> down the hill quite nicely with the rear wheels locked up.
>>>>
>>>> The presentation at Branson that I gave was a draft ( or worse ! ) , it
>>>> was cleaned up and edited once I returned home and shows the OEM coach
>>>> braking data on our website AND on the GMCMI tech site.
>>>>
>>>> The main reason the Kelsey Hayes caliper mount is not a “
>>>> casting” a Detroit originally designed , was ; I had no control
>>>> over quality assurance of the casting , I did however have control
>> over
>>>> the welded steel assembly , ya ! it looks a bit funny but it was tested
>>>> to over double to whatever stress it was ever to encounter.
>>>>
>>>> Trevor; we need more data and clarification as to your needs, hopefully
>>>> we can be of some assistance, check with Rob & Peter in the “
>> land
>>>> down under” to see what they have done .
>>>>
>>>> Cheers …….Albert
>>>> The 23 foot Birchaven , Tiverton, ON, CAN
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Sully
77 Royale basket case.
Future motorhome land speed record holder(bucket list)
Seattle, Wa.
|
|
|
|
| Re: Disc Brake Park Brake Again [message #241241 is a reply to message #240937] |
Mon, 24 February 2014 21:17 |
 |
WildBill
Messages: 232
Registered: January 2014
Karma: 1
|
Senior Member |
|
|
|
You talk about disk brakes dragging, have not searched or researched it concerning gmc's but master cylinders for drum brakes have residual valves. These valves keep about 7 psi in The line between the master and wheel cylinders . Some guys just do a sheet metal screw in the brass fitting in the master, I prefer to use a 8/32 tap and machine screw to pull the flare seat out. Behind it you will find a rubber and plastic valve, just discard it and start the brass flare fitting back in the master, once you can get the tube fitting started in threads you can use it to press the fitting back where it belongs. With a residual valve in a disc brake system you will always have brake drag. Disk brakes rely on return to zero pressure and natural square cut seal ring flexing back providing minimal but enough disk/pad clearance.
|
|
|
|
Goto Forum:
Current Time: Fri Oct 11 02:16:36 CDT 2024
Total time taken to generate the page: 0.01313 seconds
|
GMCforum
Search
Help
Register
Login
Home
