| [GMCnet] Disc Brake Park Brake Again [message #240987] |
Sun, 23 February 2014 11:38  |
Thomas Pryor
Messages: 143
Registered: January 2011
Karma: 1
|
Senior Member |
|
|
Your research is spot on. Parking Brakes are to be of Mechanical function
and must be interpreted to NOT ALLOW "Hydraulic Line locks" or Linear
Actuators.
While I was in Fremont California in Late Jan. spent time at APPLIED GMC
fitting up a coach with a Intermediate wheel GMIII caliper and Rear wheel
Drum. Both were fitted with Reaction Arms. Jim K tested the Service
Brakes while I Watched the Rear Wheel action at 45 MPH.
As in the Video for Drum/Drum ALL REAR WHEELS contributed to the stop. e
http://www.youtube.com/watch?v=1peHuX6NpH0&feature=youtu.be
The real surprise was the effectiveness of the rear wheel only Parking
brake. (Thanks ALEX SIRIUM) The Intermediate parking brake cable was
connected to the rear wheels only. The intermediate wheel was abandoned
for parking brake purposes
1. The PB lever fulcrum was extended to its lowest position as the start
point.
2. Utilizing the stock cables and adding inexpensive pulleys to replace
S hooks at the side frame, ALL LASH was removed from the cable system.
3. The Service brakes were then adjusted to allow the rear wheels to
rotate freely.
4. The PB lever fulcrum was then adjusted Upwards until the lever could
no longer be actuated over the "sweet spot" without the help of a 8"
extension. Adjustment was then backed off to achieve actuation without
assistance.
The 26' coach was then road tested again. This time The parking Brake was
activated, transmission placed in Drive and accelerated.
The coach remained stopped until the Tachometer reached 2500 RPM. To
further test the PB, Jim tried to accelerate further to move the coach and
simulate the DRIVE OFF of a Parking Brake engaged situation. When
acceleration ceased the coach stopped in a fashion that could not be
overlooked.
This modification copies the current designs on all Passenger and Trucks
here in North America. All service brakes are disc type and a shoe in
Drum actuated by cable for the Parking Brake. OEM's have been unable to
make an reliable / effective Disc style parking Brake virtually across the
North American fleet.
For Those of you who are looking for an effective, legal / inspection
compliant, and cost effective Parking brake system Consider the Rear Drum
Parking brake only modification. By the Way you will get the improvement on
the DISC/DRUM REACTION ARM SYSTEM.
http://www.appliedgmc.com/prod.itml/icOid/1510
For those of you who already have a reaction arm system fitted with all
wheel discs, I am committed to supplying you a rear drum parking brake
rescue kit if there is any interest. I am sure the the Metic caliper
reaction arm system and the All GM Caliper systems with or without Reaction
arms can be retro fitted and improved.
--
Regards,
4188 Limerick Dr
Lake Wales, Fl 33859
Cell 248 470 9186
Living on a waterfront is not a matter of life or death. Its more
important than that.
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
| Re: [GMCnet] Disc Brake Park Brake Again [message #241037 is a reply to message #240987] |
Sun, 23 February 2014 18:18  |
 |
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
|
Senior Member |
|
|
Tom,
When I bought Double Trouble it had Cadillac disks on all four rear wheels with no parking brakes. I wanted to register it in New
Jersey (a story for another time).
Too overcome the problem Ken Frey removed the rear disks as they don't do much unless you have a reaction arm system and installed
drums.
In New Jersey vehicle inspections are performed by the State. The day before I went to have the GMC inspected I adjusted the shoes
so they dragged a tiny bit, then moved on to the cables to the rear brakes and made them as tight as I could without actuating the
brakes.
When I arrived at the inspection station I screwed the adjustment on the knob WAY out then turned the GMC over to one of the state
inspectors. When he got to the parking brake test area I watched him straining to pull up the parking brake lever. He hit the gas
and the coach didn't move so it passed.
By the way, I rented a VW (can't remember the model) last summer from Avis, it DID NOT HAVE a parking brake lever; it had a button
you pushed to actuate the parking brake, this makes me suspect that the regulations have changed?
Trevor,
I would suggest the simplest way out of your predicament is to purchase four of these:
http://www.tsmmfg.com/3110.html or http://www.tsmmfg.com/3120.html I'm not sure which caliper fits.
For a brake lever and cables contact Bob Stone (bought all GMRECS inventory) on (six 1 eight) 9 six 4 nine1 two 4.
The Blue Streaks PO relocated the brake lever you can see it in this photo:
http://www.gmcmhphotos.com/photos/the-blue-streak-rhd-conversion/p52202-rhd-dash.html
Regards,
Rob M.
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
-----Original Message-----
From: Thomas Pryor
Your research is spot on. Parking Brakes are to be of Mechanical function
and must be interpreted to NOT ALLOW "Hydraulic Line locks" or Linear
Actuators.
While I was in Fremont California in Late Jan. spent time at APPLIED GMC
fitting up a coach with a Intermediate wheel GMIII caliper and Rear wheel
Drum. Both were fitted with Reaction Arms. Jim K tested the Service
Brakes while I Watched the Rear Wheel action at 45 MPH.
As in the Video for Drum/Drum ALL REAR WHEELS contributed to the stop. e
http://www.youtube.com/watch?v=1peHuX6NpH0&feature=youtu.be
The real surprise was the effectiveness of the rear wheel only Parking
brake. (Thanks ALEX SIRIUM) The Intermediate parking brake cable was
connected to the rear wheels only. The intermediate wheel was abandoned
for parking brake purposes
1. The PB lever fulcrum was extended to its lowest position as the start
point.
2. Utilizing the stock cables and adding inexpensive pulleys to replace
S hooks at the side frame, ALL LASH was removed from the cable system.
3. The Service brakes were then adjusted to allow the rear wheels to
rotate freely.
4. The PB lever fulcrum was then adjusted Upwards until the lever could
no longer be actuated over the "sweet spot" without the help of a 8"
extension. Adjustment was then backed off to achieve actuation without
assistance.
The 26' coach was then road tested again. This time The parking Brake was
activated, transmission placed in Drive and accelerated.
The coach remained stopped until the Tachometer reached 2500 RPM. To
further test the PB, Jim tried to accelerate further to move the coach and
simulate the DRIVE OFF of a Parking Brake engaged situation. When
acceleration ceased the coach stopped in a fashion that could not be
overlooked.
This modification copies the current designs on all Passenger and Trucks
here in North America. All service brakes are disc type and a shoe in
Drum actuated by cable for the Parking Brake. OEM's have been unable to
make an reliable / effective Disc style parking Brake virtually across the
North American fleet.
For Those of you who are looking for an effective, legal / inspection
compliant, and cost effective Parking brake system Consider the Rear Drum
Parking brake only modification. By the Way you will get the improvement on
the DISC/DRUM REACTION ARM SYSTEM.
http://www.appliedgmc.com/prod.itml/icOid/1510
For those of you who already have a reaction arm system fitted with all
wheel discs, I am committed to supplying you a rear drum parking brake
rescue kit if there is any interest. I am sure the the Metic caliper
reaction arm system and the All GM Caliper systems with or without Reaction
arms can be retro fitted and improved.
_______________________________________________
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 #241059 is a reply to message #240987] |
Sun, 23 February 2014 20:49 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
|
Senior Member |
|
|
NICE, Tom.
One thing I've considered but never gotten around to trying is using
mechanical-only rear drums. In other works, using the rears for
parking butdisconnecting the hydraulics. Two reasons for doing that:
One, now moot
because of reaction arms, was to eliminate rear wheel lockup. The second
reason may still be valid: There should never be a need to manually adjust
the brakes because there'd be no wear when used only for parking. A third,
or perhaps now First, reason is cost savings -- why bother with reaction
arms for the rear wheels if they're never dynamically braked?
I'll be anxiously awaiting your test results. :-)
Ken H.
On Sun, Feb 23, 2014 at 12:38 PM, Thomas Pryor wrote:
> Your research is spot on. Parking Brakes are to be of Mechanical function
> and must be interpreted to NOT ALLOW "Hydraulic Line locks" or Linear
> Actuators.
> ...
_______________________________________________
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 #241060 is a reply to message #241059] |
Sun, 23 February 2014 20:56 |
Hal StClair
Messages: 971
Registered: March 2013
Location: Rio Rancho NM
Karma: -12
|
Senior Member |
|
|
The Buick LaCrosse has an electric operated parking brake as does the new C7 Corvette. There may be others so I'm guessing the rules must have changed.
Hal
"I enjoy talking to you. Your mind appeals to me. It resembles my own mind, except you happen to be insane."
1977 Royale 101348,
1977 Royale 101586, Diesel powered,
1974 Eagle Bus 45',w/slideout,
Rio Rancho, NM
|
|
|
|
|
|
|
|
| Re: [GMCnet] Disc Brake Park Brake Again [message #241259 is a reply to message #241225] |
Tue, 25 February 2014 00:29 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
|
Senior Member |
|
|
| WildBill wrote on Mon, 24 February 2014 17:50 |
That's an interesting thought, if the rears are doing nothing but locking up and flat spotting tires they aren't contributing to braking anyways. I was just going to ask if any benefits or negatives even though I'm staying drums as far as eliminating one set from the park brake. I'm installing pulleys to reduce friction, even the front main cable but just wondering if any downside when for the time being keeping 4 drums anyways. I guess getting rid of hydraulics on the rear set would put a higher heat factor on the operational brakes going down mountains when your not in a panic situation. I understand a lot of people install wheel cylinders with smaller cups than the front to help the issue, what sizes, part numbrs?
|
Are you thinking of the modification that was done by some awhile ago. 80 mm caliper front caliper, one size larger middle wheel cylinder and original size rear?
Roy Keen
Minden,NV
76 X Glenbrook
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
