Getting a dependable park brake. Disc,or not.

B

Bob Dunahugh

New member
Sep 17, 2012
2,784
4
3
Have rear drum. Middle disc. Thought of air actuated. In a talk with Ken Henderson today. He mentioned a lineal actuator. Made some drawings this afternoon. Think that I've figured out most of the details. Anyone tried something like this?
Bob Dunahugh
4 COPO Yenkos
 
Hal St. Clair uses LAs on his diesel coach.

Care to share your details? I think one LA per side makes sense, but have to figure out how to move the coach if it freezes in the 'on' position.
--
Bill Van Vlack
'76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath, Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o mid
November 2015.
 
My personal opinion is that I like to keep as many things mechanical and
not rely on electrical.
Electrical is great but we have seen lot of basic things that an be done to
improve the parking brake system.
John Bush has shown us his system that works well without muh cash outlay.
We can email the info if requested.

On Tue, Dec 17, 2019 at 6:04 AM Bruce Hislop via Gmclist <

> Just about everything you need to know about the GM brakes and parking
> brakes improvements by Al Branscombe. His contact info is at the end of the
> presentation.
>
>
> https://www.gmcmi.com/wp-content/uploads/2013/02/GMCMH_Parking_Brake_Improvements1r5spring2011webr1.pdf
>
> --
> Bruce Hislop
> ON Canada
> 77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.1 ton front end
> http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
> My Staff says I never listen to them, or something like that
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmcrvparts.com
1-800-752-7502
 
I used a singe LA that pushes and pulls a bell crank. The cables attach to opposite ends of the bell crank so they both pull or relax together when
the LA is extended/retracted. You have to be careful with the amount of force applied as the caliper parking brake arm isn't too robust and can be
easily bent. I also used pulleys at the frame where the cables pass to reduce the friction. I had thought of making the pressure adjustable by varying
the voltage but it seems to work well enough that other 'things' could use my attention :p
Hal
--
1977 Royale 101348,

1977 Royale 101586, Diesel powered,

1975 Eleganza II, 101230,

1974 Eagle Bus 45',w/slideout,

Rio Rancho, NM
 
I have yet to use the parking brake on any of the three coaches I've had. I* use 4x4 blocks of treated wood to chock the wheels. Never failed yet.

--johnny
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
 
We live on an island, so have to take the 5-minute ferry when we leave with the GMC. The waiting line is on a downhill grade, enough that I don't want
to put it in park while waiting for up to an hour during busy times. So, I hold my foot on the pedal. Also, sometimes the skipper hits the dock
somewhat hard - enough that you can tell which cars have a parking brake set. A working parking brake would be pretty handy.

Anyone know what John Bush's system is?
--
Bill Van Vlack
'76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath, Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o mid
November 2015.
 
Told you people I can send info.
Ask....

On Wed, Dec 18, 2019 at 9:08 AM Bill Van Vlack via Gmclist <

> We live on an island, so have to take the 5-minute ferry when we leave
> with the GMC. The waiting line is on a downhill grade, enough that I don't
> want
> to put it in park while waiting for up to an hour during busy times. So, I
> hold my foot on the pedal. Also, sometimes the skipper hits the dock
> somewhat hard - enough that you can tell which cars have a parking brake
> set. A working parking brake would be pretty handy.
>
> Anyone know what John Bush's system is?
> --
> Bill Van Vlack
> '76 Royale; Guemes Island, Washington; Twin bed, full (DS) side bath,
> Brazilian Redwood counter and settee tops,455, 6KW generator; new owner a/o
> mid
> November 2015.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmcrvparts.com
1-800-752-7502
 
Hi Jim

What is John Bushes parking brake system?

bdub

-----Original Message-----
From: Gmclist On Behalf Of Jim Kanomata via Gmclist
Sent: Wednesday, December 18, 2019 11:23 AM
Subject: Re: [GMCnet] Getting a dependable park brake. Disc,or not.

Told you people I can send info.
Ask....

On Wed, Dec 18, 2019 at 9:08 AM Bill Van Vlack via Gmclist <

> We live on an island, so have to take the 5-minute ferry when we leave
> with the GMC. The waiting line is on a downhill grade, enough that I don't
> want
> to put it in park while waiting for up to an hour during busy times. So, I
> hold my foot on the pedal. Also, sometimes the skipper hits the dock
> somewhat hard - enough that you can tell which cars have a parking brake
> set. A working parking brake would be pretty handy.
>
> Anyone know what John Bush's system is?
 
I'm guessing Jim K just threw his arms up in the air and muttered a few choice words after that post ^^^^^^
--
Rich Mondor,

Brockville, ON

77 Hughes 2600
 
If you are on a slope, and by yourself, and your parking pawl isn’t
engaging, I hope you can run fast.

Rick “BTDT” Denney

On Wed, Dec 18, 2019 at 11:55 AM Johnny Bridges via Gmclist <

> I have yet to use the parking brake on any of the three coaches I've had.
> I* use 4x4 blocks of treated wood to chock the wheels. Never failed yet.
>
> --johnny
> --
> Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
> Braselton, Ga.
> I forgive them all, save those who hurt the dogs. They must answer to me
> in hell
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
'73 X-Glacier 230 "Jaws"
Northern Virginia
Offlist email: rick at rickdenney dot com
 
Normally, I would advise AGAINST a "line lock" parking brake, but, the GMC
parking brake, as installed, will not hold a GMC coach on the ramp to many
ferry landings that I have been on in Washington State. IF THE DRIVER
REMAINS AT THE WHEEL, this might be one of the very few times that a "line
lock" could be useful. I guess that nothing but death is forever. I still
will not install one of them.
Jim Hupy
Salem, Oregon

On Wed, Dec 18, 2019, 1:47 PM Richard Denney via Gmclist <

> If you are on a slope, and by yourself, and your parking pawl isn’t
> engaging, I hope you can run fast.
>
> Rick “BTDT” Denney
>
> On Wed, Dec 18, 2019 at 11:55 AM Johnny Bridges via Gmclist <

>
> > I have yet to use the parking brake on any of the three coaches I've had.
> > I* use 4x4 blocks of treated wood to chock the wheels. Never failed yet.
> >
> > --johnny
> > --
> > Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
> > Braselton, Ga.
> > I forgive them all, save those who hurt the dogs. They must answer to me
> > in hell
> >
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
> --
> '73 X-Glacier 230 "Jaws"
> Northern Virginia
> Offlist email: rick at rickdenney dot com
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
I was really hope that Thomas Pryor Esq. would join in here. And that is mostly for one reason, but I have two.

Prior to the incident in the spring, I did have a completely OE parking brake that would hold the coach on an incline, but I never tested how much
incline that might withstand.

We came home from the adventure in South Carolina with the Engine/Transmission about an inch and an half farther forward that it is supposed to be.
As a result, Reverse was now drive (I unplugged the backup lights), there was no park to be had at all and the parking brake was nowhere to be found.
Fortunately, Mary had decided to run consort in the rental car for the return to Michigan some 982 miles distant. Any time I stopped, I would have to
wait for her to stop the car, and come along side to grab the block out of the doorway and put it someplace good. This had to happen any time a stop
did not allow me to roll up to something solid.

This was only real bad when the right hood popped on the interstate. It was RAINING (emphasis intended). As you all know, we made it home. I did
vow to get the parking brake working after the driveline was put back in place. I do barely have it working now, but it is a planned winter program.
I do not want to be without a parking brake again. The thing that we all have to be conscious of here is that there are about eleven common mode
failures that will make the transmission park function worthless.

The reason I wanted Tom to stop by is that he reported that he very successfully got the parking brake to work very well by giving up the intermediate
brake and just going to the rear. He and I talked about this at some length, but I did not take any notes and his plan may be very workable for many
others. It also might work for me, but my first shot will be making it work right. We will see about before spring in Paterson.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit
 
For those that worry about a possible park brake issue or if something like Matt's incident happens there is a simple yet effective way to make a
temporary "park brake" or if you just need "more" brake power.......its called a "stick"....yup just simply wedge a suitable length stick, broom
handle, prybar etc between the drivers seat bottom cushion face and the brake pedal applying the pedal force you want on the brakes. We use it in the
shop to hold vehicles when peoples park brakes dont work......

So you may want to keep one pre-cut in your rig just in case..... :d
--
Rich Mondor,

Brockville, ON

77 Hughes 2600
 
Since there seems to be unusual interest in parking brakes, I'll describe
the system I mentioned to Bob D. Caution: While highly effective and,
IMHO, a vast improvement over line locks, it IS hydraulic and will NOT
satisfy government requirements for mechanical brakes.

Back in 2007, the EBC Yellow Brake Pads were receiving a lot of publicity.
I wanted to test the claims, so I conducted a sorta scientific test:
http://www.gmcmhphotos.com/photos/g4642-calibrated-brake-tests.html

About 5 years later I was disgusted with all my attempts to make disk
parking calipers effective, and remembered that the 1-1/4" pneumatic
cylinder was still riding around under my right foot and still connected to
the brake pedal with a chain. Having a tiny new Thomas air compressor on
hand, it occurred to me that they could work together. Using those, and a
spare suspension control valve, I rigged a 6-wheel (or 10-wheel when towing
with toad brakes active) parking brake. On the dash there's a Parking
Brake switch. Any time it's turned ON the compressor produces about 120
psi. That pressure applied to the 1-1/4" cylinder results in about a 150
lbf pull on the brake pedal. That's enough to lock up the brakes when
static, or result in a RAPID stop.

If the ignition is ON, turning the Park switch to OFF releases the brakes
by turning the compressor off and valve-dumping the pressure. If the
ignition is OFF, turning the Park switch OFF has no effect, and the
compressor, with a pressure switch in the circuit, runs about every 30
minutes for maybe 3 seconds to correct the tiny leakage still in the
system. I haven't figured out how long the engine battery will last under
that load, but it's a LONG time -- certainly measured in days, probably
weeks. I can get chocks in place before then.

I HAVE tried it in an emergency on what must be one of the steepest hills
in Seattle and it worked perfectly. I've lost all incentive to achieve a
functional "legal" parking brake.

Ken H.

On Mon, Dec 16, 2019 at 6:40 PM Bob Dunahugh via Gmclist <

> Have rear drum. Middle disc. Thought of air actuated. In a talk with
> Ken Henderson today. He mentioned a lineal actuator. Made some drawings
> this afternoon. Think that I've figured out most of the details. Anyone
> tried something like this?
> Bob Dunahugh
> 4 COPO Yenkos
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Here's a slightly more elegant stick. ;-)

http://www.gmcmhphotos.com/photos/g6433-kiss-parking-brake.html

bdub

On Wed, Dec 18, 2019, 8:53 PM tonka6cuda6--- via Gmclist <

> For those that worry about a possible park brake issue or if something
> like Matt's incident happens there is a simple yet effective way to make a
> temporary "park brake" or if you just need "more" brake power.......its
> called a "stick"....yup just simply wedge a suitable length stick, broom
> handle, prybar etc between the drivers seat bottom cushion face and the
> brake pedal applying the pedal force you want on the brakes. We use it in
> the
> shop to hold vehicles when peoples park brakes dont work......
>
> So you may want to keep one pre-cut in your rig just in case..... :d
> --
> Rich
>
 
After more thought. And making some diagrams. Over the linier actuator. I keep coming back to my first idea last year. Went I got another Dana compressor. Compressor on/off pleasure switch. Like what's used now with the rear air ride system. Then a small air tank. It's about 5 inches dia. 12 inches long. Then use one air cylinder for each side. This will provide some redundancy in the system. It could be setup to apply the park brake. Every time that the ignition switch is turned off. If desired. This would make sure that you never forgot. This feature could be on an. As required status. I see this system. As never needing any future adjustments. Think that this could be made up as an install kit.
Bob Dunahugh
78 Royale
4 COPO Yenkos
.
________________________________
From: Ken Henderson
Sent: Thursday, December 19, 2019 6:49 AM
To: GMC Mail List
Cc: Bob Dunahugh
Subject: Re: [GMCnet] Getting a dependable park brake. Disc,or not.

Since there seems to be unusual interest in parking brakes, I'll describe the system I mentioned to Bob D. Caution: While highly effective and, IMHO, a vast improvement over line locks, it IS hydraulic and will NOT satisfy government requirements for mechanical brakes.

Back in 2007, the EBC Yellow Brake Pads were receiving a lot of publicity. I wanted to test the claims, so I conducted a sorta scientific test:
http://www.gmcmhphotos.com/photos/g4642-calibrated-brake-tests.html

About 5 years later I was disgusted with all my attempts to make disk parking calipers effective, and remembered that the 1-1/4" pneumatic cylinder was still riding around under my right foot and still connected to the brake pedal with a chain. Having a tiny new Thomas air compressor on hand, it occurred to me that they could work together. Using those, and a spare suspension control valve, I rigged a 6-wheel (or 10-wheel when towing with toad brakes active) parking brake. On the dash there's a Parking Brake switch. Any time it's turned ON the compressor produces about 120 psi. That pressure applied to the 1-1/4" cylinder results in about a 150 lbf pull on the brake pedal. That's enough to lock up the brakes when static, or result in a RAPID stop.

If the ignition is ON, turning the Park switch to OFF releases the brakes by turning the compressor off and valve-dumping the pressure. If the ignition is OFF, turning the Park switch OFF has no effect, and the compressor, with a pressure switch in the circuit, runs about every 30 minutes for maybe 3 seconds to correct the tiny leakage still in the system. I haven't figured out how long the engine battery will last under that load, but it's a LONG time -- certainly measured in days, probably weeks. I can get chocks in place before then.

I HAVE tried it in an emergency on what must be one of the steepest hills in Seattle and it worked perfectly. I've lost all incentive to achieve a functional "legal" parking brake.

Ken H.

Have rear drum. Middle disc. Thought of air actuated. In a talk with Ken Henderson today. He mentioned a lineal actuator. Made some drawings this afternoon. Think that I've figured out most of the details. Anyone tried something like this?
Bob Dunahugh
4 COPO Yenkos
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Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
Would it be possible to use an air spring out of a truck brake. This would require air pressure to release probably controlled by a electric solenoid
. In the event of no air or electricity then the brakes would be applied. This would then be a fail safe system
--
Trevor
Brisbane Australia
Siesta Koala 76 Edgemont (old Bobby Moores)
71 Cadillac Eldo Convert
58 Cadillac Eldorado Brougham Project
 
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