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[GMCnet] Brake Problems [message #270631]

Wed, 28 January 2015 07:20

Advanced Concept Ener

Messages: 112
Registered: December 2014

Karma: 0

Senior Member

I have a 76 Palm Beach with 2 ft stretch behind rear wheels. Factory original type brakes but former owner had made a lot of add ons that we couldn’t figure out so we ripped them out and went back to factory original Bought coach last April and had it delivered to Jim Bounds. Jim went over the entire coach and did basics and upgrades to interior. Replaced brakes including wheel cylinders, hoses ,shoes, master Cylinder, proportioning valve, and installed vacuum storage pipe. Drove from Florida to NJ and the brakes were getting lower all the way. They were never really very high and I never could lock up wheels in rear like my 78 Royale did. At home I replaced all the brake shoes again, hardware, new 80mm calipers, wheel bearings, and installed new sensitized booster. Checked rod on booster for proper length. Bled brakes numerous time, pressure , gravity, reverse and vacuum. Replace proportioning valve with original factory steel unit from brass. Replaced the master cylinder again. Replaced master cylinder again with P-30 (more volume). Have brake pedal when engine is off, goes down to within 1” of floor when engine starts. Hardly any rear brakes when I try them. Brought coach to Ken Frey. He fixed a few of my screws but now he is replacing booster again with a replacement that Jim Bounds kindly sent him on my behalf. I bought new stainless lines from upstate NY (can’t remember name) but haven’t put them in yet because we would have to start the bleeding process all over again. At http://www.henry-davis.com/GMC/Sandy/ I found a similar issue that was discussed under brakes in October 2 1998 by Poise but his original problem was with an Eaton line failure. Everything has been replaced twice, all the experts have been called to discuss, Bounds, Sirum, Golby, Applied, Frey. ATE DOT 4 fluid getting expensive to bleed. ANYBODY HAVE ANY IDEA? Next step is to rip all the drum brakes off!

Jon Darcy
aces4nrg@gmail.com

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Re: [GMCnet] Brake Problems [message #270633 is a reply to message #270631]

Wed, 28 January 2015 07:56

lqqkatjon

Messages: 2324
Registered: October 2010
Location: St. Cloud, MN

Karma: 5

Senior Member

Only thing I can think of would be a line leak that you have not found.

Jim Hupy's bleeder:
http://www.bdub.net/jhupy/

pressurize system, and see if you can find some fluid.??

I have all stock brakes, and I do have a leak in the rear, but the pedel pressure is always good. I just need to make sure my rear reservoir gets checked before I drive anywhere.

Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/

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Re: [GMCnet] Brake Problems [message #270634 is a reply to message #270633]

Wed, 28 January 2015 08:08

94nubble

Messages: 275
Registered: July 2011
Location: Chesapeake VA

Karma: 3

Senior Member

Jon
I had the same problem with my coach. After many tries to bleed the brakes, I found that the system still had air in it. I bought a bleed plate from Jim Hupy http://bdub.net/jhupy/. After using his plate, I now have good pedal that doesn't fade.

Tom McManus
1977 Royale
Chesapeake VA

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Re: [GMCnet] Brake Problems [message #270638 is a reply to message #270631]

Wed, 28 January 2015 09:33

kerry pinkerton

Messages: 2565
Registered: July 2012
Location: Harvest, Al

Karma: 15

Senior Member

Sure sounds like air in the system. Are you losing any fluid?

Ken Frey knows what he is doing and will figure it out I bet. While chasing the problem, I'd probably use Dot3. Pushing that out with the high dollar stuff after all the head scratching is done is easy with a pressure bleeder and I'm sure that Ken has one.

Kerry Pinkerton - North Alabama Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L

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Re: [GMCnet] Brake Problems [message #270639 is a reply to message #270631]

Wed, 28 January 2015 09:37

kerry pinkerton

Messages: 2565
Registered: July 2012
Location: Harvest, Al

Karma: 15

Senior Member

My pedal is also low but firm and my brakes work fine, just always had a low pedal. I'm under the impression that is a nature of the beast.

Slightly different thing for consideration is Bob Stone's Powermaster brake booster conversion (Operates off the power steering pump and uses hydraulic pressure instead of vacuum for the booster. GM used it in lots of duallys and larger trucks. A lot of folks saw and drove this at the Chippewa convention. I don't know if Ken did but I'm sure he heard people talking about how amazing it worked. Some people I really respect were impressed.

Kerry Pinkerton - North Alabama Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L

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Re: [GMCnet] Brake Problems [message #270680 is a reply to message #270631]

Wed, 28 January 2015 18:01

Matt Colie

Messages: 8547
Registered: March 2007
Location: S.E. Michigan

Karma: 7

Senior Member

Advanced Concept Ener wrote on Wed, 28 January 2015 08:20

I have a 76 Palm Beach with 2 ft stretch behind rear wheels. Factory original type brakes but former owner had made a lot of add ons that we couldn't figure out so we ripped them out and went back to factory original Bought coach last April and had it delivered to Jim Bounds. Jim went over the entire coach and did basics and upgrades to interior. Replaced brakes including wheel cylinders, hoses ,shoes, master Cylinder, proportioning valve, and installed vacuum storage pipe. Drove from Florida to NJ and the brakes were getting lower all the way. They were never really very high and I never could lock up wheels in rear like my 78 Royale did. At home I replaced all the brake shoes again, hardware, new 80mm calipers, wheel bearings, and installed new sensitized booster. Checked rod on booster for proper length. Bled brakes numerous time, pressure , gravity, reverse and vacuum. Replace proportioning valve with original factory steel unit from brass. Replaced the master cylinder again. Replaced master cylinder again with P-30 (more volume). Have brake pedal when engine is off, goes down to within 1" of floor when engine starts. Hardly any rear brakes when I try them. Brought coach to Ken Frey. He fixed a few of my screws but now he is replacing booster again with a replacement that Jim Bounds kindly sent him on my behalf. I bought new stainless lines from upstate NY (can't remember name) but haven't put them in yet because we would have to start the bleeding process all over again. At http://www.henry-davis.com/GMC/Sandy/ I found a similar issue that was discussed under brakes in October 2 1998 by Poise but his original problem was with an Eaton line failure. Everything has been replaced twice, all the experts have been called to discuss, Bounds, Sirum, Golby, Applied, Frey. ATE DOT 4 fluid getting expensive to bleed. ANYBODY HAVE ANY IDEA? Next step is to rip all the drum brakes off!

Jon Darcy

Jon,

You did bench bleed the new masters right??
That sure sounds like air to me.

Silly question time....
Have you manually adjusted the rear brakes?
When you get the rears open look at and confirm that the auto-adjusters are rigged right and are working. If you can get the drums off without backing the adjusters down, the auto-adjust is probably not working.

Unfortunately, I think you missed Dave Lenzi's session at Montgomery. A P-30 makes lower final pressure than the OE even with a sensitized booster.

Next - an opinion - Rather than go to disks on the rear, take the drum brakes off long enough to put on the floating back plates (aka reaction arm set) for the drums and that way you can keep you parking brake and still be legal in NJ.

Matt

Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

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Re: [GMCnet] Brake Problems [message #270699 is a reply to message #270631]

Wed, 28 January 2015 21:23

Steve

Messages: 506
Registered: September 2013
Location: East Greenville, Pa

Karma: 1

Senior Member

Jon,

I don't have an answer on your brakes but I did see your coach on the lift at Ken Frey's shop on Monday morning. It looks good. I liked the fender flares. I had just stopped in to say hi to Ken and noticed a nice stretch on the lift.

I am local to the area. If you needed assistance in some way I would try to help. I'm on the Black List, or PM me here on the forum

Good luck. I think you are in good hands with Ken.

1978 GMC Royal
Eastern Pennslyvania
1968 Chevrolet C20 396 Camper Special
1969 Chevrolet C20 Camper Special
1985 Buick Electra Park Avenue
1992 Camaro 25th Anniversary Heretage Edition Black

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Re: [GMCnet] Brake Problems [message #270702 is a reply to message #270631]

Wed, 28 January 2015 22:37

Rick Staples

Messages: 126
Registered: May 2014
Location: Johnstown, Colorado, USA

Karma: -1

Senior Member

Jon Darcy wrote:
" Have brake pedal when engine is off, goes down to within 1" of floor when engine starts. Hardly any rear brakes when I try them. "

Jon,
The first question is whether the pedal is spongy (air in the system), or just low but solid. I found my '75 GMC fairly easy to bleed by gravity, and it sounds like you've bled the heck out of it, so I'm wondering about other things. One thing I'd try is readjusting the rear shoes. The self-adjusters are nearly useless (Few of us back up and hit the brakes hard.), so do it the old=-fashioned way:

-Raise and support the rear, wheels off the ground but tires in place.

-Back off the parking brake cables until they are very loose. (Make SURE they aren't sticking near the brake from rust or whatever.)

-Now one at a time, tighten the brake adjusters with a brake spoon or bent screwdriver, turning the wheel back and forth every few clicks on the adjuster, until the wheel completely locks up. (Can't turn it by hand.) Note the feel of the wheel turning as you do this. You'll probably find that it drags more in some spots than others, indicating the drum is out-of-round and/or not concentric on the hub. If it is TOO uneven, you may need to resurface or replace the drum. (Even NEW drums aren't always perfect.)

-Finally, loosen the adjuster a little at a time, trying to turn the wheel back and forth (You'll have to get another tool through the hole to hold the self-adjuster away. PITA.) until the wheel can be turned with a little drag. (New shoes and new/resurfaced drums, more drag, otherwise, less drag)
NOW, try your pedal, see if it's better, and if the rear brakes work. If they do, great, if not I apologize for wasting a couple hours of your time. Wink

Wink

If things are better, only then readjust the e-brake cables, but not so tight they significantly increase the drag.

Remember, you'll have to repeat this whole process after a few hundred miles as the shoes wear in, but you'll get even better braking when you do. What I've found in many cases is that the E-brake cables, through misadjustment or sticking, cause the shoes to make only partial contact with the drums. This give lousy braking, and the shoes sort of bend when the cylinder pushes on them, giving a low, slightly spongy pedal.

FWIW, my '75 Eleganza, with the oversize front calipers, Jim Bounds' enhanced booster and master cylinder (which DO raise the brake pedal more than I'd like), 1/16" oversize leading rear cylinders, and Jim Kanomata drums, can lock up several rear wheels in a panic stop. (Not sure how many, there was too much tire smoke!) As we used to say, "It'll stop on a dime, and give you 9¢ change!"

HTH. YMMV.
Rick

Rick Staples, '75 Eleganza, Johnstown, CO "Advice is a dangerous gift, even from the Wise to the Wise, and all paths may run ill." -Tolkien

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Re: [GMCnet] Brake Problems [message #270725 is a reply to message #270631]

Thu, 29 January 2015 08:47

Gary Berry

Messages: 1002
Registered: May 2005

Karma: -1

Senior Member

Hey Jon;

Good to see another stretch owner. Your problem reminded me of a similar problem that Bert and Fay Curtis had a number of years ago. They did all of the similar gyrations on their brake system. They fixed it by having the brake pads arched to match the brake drums. Each of the pads were just running on the tips. Not sure where one can have arcing done, but it fixed their problem.

Gary Berry
73 CL Stretch
Currently in AZ

Sent from my iPad

> On Jan 28, 2015, at 6:20 AM, Jon Darcy wrote:
>
> I have a 76 Palm Beach with 2 ft stretch behind rear wheels. Factory original type brakes but former owner had made a lot of add ons that we couldn’t figure out so we ripped them out and went back to factory original Bought coach last April and had it delivered to Jim Bounds. Jim went over the entire coach and did basics and upgrades to interior. Replaced brakes including wheel cylinders, hoses ,shoes, master Cylinder, proportioning valve, and installed vacuum storage pipe. Drove from Florida to NJ and the brakes were getting lower all the way. They were never really very high and I never could lock up wheels in rear like my 78 Royale did. At home I replaced all the brake shoes again, hardware, new 80mm calipers, wheel bearings, and installed new sensitized booster. Checked rod on booster for proper length. Bled brakes numerous time, pressure , gravity, reverse and vacuum. Replace proportioning valve with original factory steel unit from brass. Replaced the master cylinder again. Replaced master cylinder again with P-30 (more volume). Have brake pedal when engine is off, goes down to within 1” of floor when engine starts. Hardly any rear brakes when I try them. Brought coach to Ken Frey. He fixed a few of my screws but now he is replacing booster again with a replacement that Jim Bounds kindly sent him on my behalf. I bought new stainless lines from upstate NY (can’t remember name) but haven’t put them in yet because we would have to start the bleeding process all over again. At http://www.henry-davis.com/GMC/Sandy/ I found a similar issue that was discussed under brakes in October 2 1998 by Poise but his original problem was with an Eaton line failure. Everything has been replaced twice, all the experts have been called to discuss, Bounds, Sirum, Golby, Applied, Frey. ATE DOT 4 fluid getting expensive to bleed. ANYBODY HAVE ANY IDEA? Next step is to rip all the drum brakes off!
>
> Jon Darcy
> aces4nrg@gmail.com
>
>
>
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Re: [GMCnet] Brake Problems [message #270726 is a reply to message #270725]

Thu, 29 January 2015 09:09

kerry pinkerton

Messages: 2565
Registered: July 2012
Location: Harvest, Al

Karma: 15

Senior Member

Gary Berry wrote on Thu, 29 January 2015 08:47

... They fixed it by having the brake pads arched to match the brake drums. Each of the pads were just running on the tips. Not sure where one can have arcing done, but it fixed their problem....

Pretty common back in the 50's and 60's. Especially on old MOPARs. I've got a buddy with a machine but I've never needed to use it. Easy to check. Pull the drum, pull the shoe, check that the arc of the shoe matches the inside of the drum.

If the drum has been turned a lot or the shoes slightly out of spec, the arc can be off enough that the shoe won't be in full contact. I'm not sure that will cause the problem that he's describing but it would definitely effect brake effectiveness.

Kerry Pinkerton - North Alabama Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L

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Re: [GMCnet] Brake Problems [message #270728 is a reply to message #270726]

Thu, 29 January 2015 09:26

GMC.LES

Messages: 505
Registered: April 2014

Karma: -2

Senior Member

If the drums were turned to max dis or beyond, you can bet the shoe arc doesn't match the drum. This results in the show lining contacting the drum only in the center(mid-point) of the shoe. Since the wheel cylinder forces are applied to the ends of the shoe, it flexes to conform to the drum. This results in more pedal travel and a slightly spongy feeling. The situation is amplified by our coaches having 4 rear drums. I've experienced it often on vehicles with rear brakes. The only solutions are: (best to worst)
1) Use new drums and new pads
2) have your shoes re-curved to match the drums
3) drive the heck out the vehicle and work the brakes until they wear in sufficiently that the pedal firmness returns. Repeated shoe adjustments will be needed if doing this.

Les Burt

> On Jan 29, 2015, at 10:09 AM, Kerry Pinkerton wrote:
>
> Gary Berry wrote on Thu, 29 January 2015 08:47
>> ... They fixed it by having the brake pads arched to match the brake drums. Each of the pads were just running on the tips. Not sure where one can
>> have arcing done, but it fixed their problem....
>
>
> Pretty common back in the 50's and 60's. Especially on old MOPARs. I've got a buddy with a machine but I've never needed to use it. Easy to check.
> Pull the drum, pull the shoe, check that the arc of the shoe matches the inside of the drum.
>
> If the drum has been turned a lot or the shoes slightly out of spec, the arc can be off enough that the shoe won't be in full contact. I'm not sure
> that will cause the problem that he's describing but it would definitely effect brake effectiveness.
> --
> Kerry Pinkerton
>
> North Alabama, near Huntsville,
>
> 77 Eleganza II, "The Lady", 403CI, Manny Brakes, 1 ton, tranny also a 76 Eleganza to be re-bodied as an Art Deco car hauler
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> Unsubscribe or Change List Options:
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Re: [GMCnet] Brake Problems [message #271147 is a reply to message #270634]

Tue, 03 February 2015 20:48

Bob de Kruyff

Messages: 4260
Registered: January 2004
Location: Chandler, AZ

Karma: 1

Senior Member

94nubble wrote on Wed, 28 January 2015 07:08

Jon
I had the same problem with my coach. After many tries to bleed the brakes, I found that the system still had air in it. I bought a bleed plate from Jim Hupy http://bdub.net/jhupy/. After using his plate, I now have good pedal that doesn't fade.

It's a quality piece of work and I wouldn't do without it !

Bob de Kruyff
78 Eleganza
Chandler, AZ

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Re: [GMCnet] Brake Problems [message #271148 is a reply to message #270726]

Tue, 03 February 2015 20:55

Bob de Kruyff

Messages: 4260
Registered: January 2004
Location: Chandler, AZ

Karma: 1

Senior Member

kerry pinkerton wrote on Thu, 29 January 2015 08:09

Gary Berry wrote on Thu, 29 January 2015 08:47
... They fixed it by having the brake pads arched to match the brake drums. Each of the pads were just running on the tips. Not sure where one can have arcing done, but it fixed their problem....

Pretty common back in the 50's and 60's. Especially on old MOPARs. I've got a buddy with a machine but I've never needed to use it. Easy to check. Pull the drum, pull the shoe, check that the arc of the shoe matches the inside of the drum.

If the drum has been turned a lot or the shoes slightly out of spec, the arc can be off enough that the shoe won't be in full contact. I'm not sure that will cause the problem that he's describing but it would definitely effect brake effectiveness.

Arcing or cam grinding is now illegal in many areas due to asbestos problems. You can buy used machines but most shops will no longer do cam grinding. Unless you are OSHA compliant, I don't think you can get a new machine. Since drum brakes are disapearing in the industry, ther aren't too many people that know how to do it correctly.

Bob de Kruyff
78 Eleganza
Chandler, AZ

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Re: [GMCnet] Brake Problems [message #271195 is a reply to message #271148]

Wed, 04 February 2015 12:42

Emery Stora

Messages: 959
Registered: January 2011

Karma: 4

Senior Member

Are you still able to find asbestos brake lining? I thought that the EPA banned it back about 1986.

Emery Stora

> On Feb 3, 2015, at 7:55 PM, Bob de Kruyff wrote:
>
> kerry pinkerton wrote on Thu, 29 January 2015 08:09
>> Gary Berry wrote on Thu, 29 January 2015 08:47
>>> ... They fixed it by having the brake pads arched to match the brake drums. Each of the pads were just running on the tips. Not sure where one
>>> can have arcing done, but it fixed their problem....
>>
>>
>> Pretty common back in the 50's and 60's. Especially on old MOPARs. I've got a buddy with a machine but I've never needed to use it. Easy to
>> check. Pull the drum, pull the shoe, check that the arc of the shoe matches the inside of the drum.
>>
>> If the drum has been turned a lot or the shoes slightly out of spec, the arc can be off enough that the shoe won't be in full contact. I'm not
>> sure that will cause the problem that he's describing but it would definitely effect brake effectiveness.
>
> Arcing or cam grinding is now illegal in many areas due to asbestos problems. You can buy used machines but most shops will no longer do cam grinding.
> Unless you are OSHA compliant, I don't think you can get a new machine. Since drum brakes are disapearing in the industry, ther aren't too many people
> that know how to do it correctly.
> --
> Bob de Kruyff

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Re: [GMCnet] Brake Problems [message #271217 is a reply to message #271195]

Wed, 04 February 2015 21:36

Bob de Kruyff

Messages: 4260
Registered: January 2004
Location: Chandler, AZ

Karma: 1

Senior Member

""Are you still able to find asbestos brake lining? I thought that the EPA banned it back about 1986.

Emery Stora
""

No, I doubt any are available even from "questionable" sources. I think the shoe grinders got caught up in the middle of the asbestos ban even though asbestos shoes are no longer available. Possibly any shoe grinding could be bad for the lungs.

Bob de Kruyff
78 Eleganza
Chandler, AZ

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Re: [GMCnet] Brake Problems [message #271223 is a reply to message #271217]

Wed, 04 February 2015 21:51

kerry pinkerton

Messages: 2565
Registered: July 2012
Location: Harvest, Al

Karma: 15

Senior Member

Bob de Kruyff wrote on Wed, 04 February 2015 21:36

...Possibly any shoe grinding could be bad for the lungs.

I expect you are right Bob but I also expect there are lots and lots of other daily tasks that are also bad for the lungs including welding, grinding, painting, sanding, etc....

Kerry Pinkerton - North Alabama Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L

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Re: [GMCnet] Brake Problems [message #271258 is a reply to message #271223]

Thu, 05 February 2015 20:40

Bob de Kruyff

Messages: 4260
Registered: January 2004
Location: Chandler, AZ

Karma: 1

Senior Member

kerry pinkerton wrote on Wed, 04 February 2015 20:51

Bob de Kruyff wrote on Wed, 04 February 2015 21:36
...Possibly any shoe grinding could be bad for the lungs.

I expect you are right Bob but I also expect there are lots and lots of other daily tasks that are also bad for the lungs including welding, grinding, painting, sanding, etc....

I'm with you--surprised I'm still alive.

Bob de Kruyff
78 Eleganza
Chandler, AZ

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