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Topic: How to set up parking brake on my 1990 gv (Read 568 times) previous topic - next topic

How to set up parking brake on my 1990 gv

Hya all, is there any set way to set up parking brake on my villa, I have brake shoes and drum assembly on the end of my gearbox which is connected to my parking brake chamber, I'm not sure if I have done it right or not, it is all connected and appears to be working, but I'm not 100% sure about the efficiency of it, firstly I have replaced the old hydraulic parking chamber with a new one, just one concern there, is that when I flick the parking brake switch in the cab, it takes about 4 or 5 seconds to fully apply, its not instant, once it is applied it appears to be holding the vehicle because I put it into forward drive and using the accelator, and the vehicle will not move and yet if I put the vehicle into reverse and use the accelerator there is a slight movement its tight but I'm thinking is it set up OK or not I am not able to turn the threaded bar anymore it is fully adjusted up as far as I can go as close to the pin that attaches to the parking lever  could it be that I need to remove the parking brake shoes and roughen them up with heavy grit sand paper, and maybe clean the inside of the drum, I have found a complete parking brake kit from Mill supply and they also sell the new drum, so I'm thinking is it better just to fit all new, but then if I can solve the problem by just cleaning everything up, why waste money, has anyone ever worked on this type of parking brake system that could advise me thanks kev
1990 foretravel grandvilla, Oshkosh chassis
8.2ltr Detroit turbo

Re: How to set up parking brake on my 1990 gv

Reply #1 –
Hey Kev,

I personally know nothing about your parking brake.  Any chance of getting some photos of your parking brake setup?  Seeing the actual device/mechanism under discussion really helps us understand the question.

A drum brake, regardless of where it is located, is normally a pretty simple device.  They all have several things in common.  First, the shoes and drum must not be contaminated by oil.  Second, the shoes and drums must be within acceptable tolerances - IE not worn out.  Third, they must be adjusted properly.  Drum brakes usually have two adjustment points.  There is the "gross" adjustment somewhere in the linkage that applies the brake, and there is the "fine" adjustment inside the brake drum.

I'm not clear about the "threaded rod" you are adjusting.  Is it outside the brake drum near the "hydraulic parking chamber", or inside the brake drum (between the shoes) and adjusted by turning a little wheel?  On a conventional drum brake that is called the "star wheel" and it is used to compensate for wear in the brake shoe lining.  As you turn the star wheel the brake shoes are moved closer to the drum.  If you have used up all the available movement in the adjustment mechanism, and the brakes are still not working correctly, then that usually indicates the brake shoes (or drum) are worn out.

If you have any question about the condition of the shoes and drum, certainly wouldn't hurt to take a look at them.  If your coach has ever been driven with the parking brake applied (I don't know if that is possible), then the shoes could be glazed from being overheated.  Sometimes minor glazing can be corrected by sanding the friction surface, but usually the best solution is new shoes.

It's been a long while since I drove cars with 4-wheel drum brakes, but I do seem to recall that the brakes were not as strong when backing up.  Something about the "single leading shoe" design not working as well in reverse.  I'm kinda foggy on that subject...well, actually, MOST subjects from that time period.  Getting old sucks.

Personally, I'd say if your coach's parking brake will hold against light throttle application in drive, then you are good to go.  Do you have to get vehicles safety tested over there prior to registration?  How do they test the parking brake?

You should carry two pair of heavy duty chocks in your coach.  If you ever have any question about the parking brake being sufficient (like on a steep hill) then use the chocks!  Better safe than sorry.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: How to set up parking brake on my 1990 gv

Reply #2 –
For those who, like me, are unfamiliar with Kev's drive shaft parking brake, here are links to prior discussions:

parking brake chamber on my 1990 foretravel grand villa

Eaton rear axle problen on my 1990 foretravel grand villa
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: How to set up parking brake on my 1990 gv

Reply #3 –
Don't know exactly if my coach setup is same as Kevin's, but BUT I do experience same slight roll after flipping the park brake lever on.
What I have discovered is if I pump the regular brake pedal on the floor the coach doesn't roll.
The ramps I made to get the coach level in our driveway do have 2x4 stops on the forward end of the ramps. Haven't gone off the front of the rams yet. (knock on wood)
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: How to set up parking brake on my 1990 gv

Reply #4 –
Quote from: Chuck & Jeannie –
Hey Kev,

I personally know nothing about your parking brake.  Any chance of getting some photos of your parking brake setup?  Seeing the actual device/mechanism under discussion really helps us understand the question.

A drum brake, regardless of where it is located, is normally a pretty simple device.  They all have several things in common.  First, the shoes and drum must not be contaminated by oil.  Second, the shoes and drums must be within acceptable tolerances - IE not worn out.  Third, they must be adjusted properly.  Drum brakes usually have two adjustment points.  There is the "gross" adjustment somewhere in the linkage that applies the brake, and there is the "fine" adjustment inside the brake drum.

I'm not clear about the "threaded rod" you are adjusting.  Is it outside the brake drum near the "hydraulic parking chamber", or inside the brake drum (between the shoes) and adjusted by turning a little wheel?  On a conventional drum brake that is called the "star wheel" and it is used to compensate for wear in the brake shoe lining.  As you turn the star wheel the brake shoes are moved closer to the drum.  If you have used up all the available movement in the adjustment mechanism, and the brakes are still not working correctly, then that usually indicates the brake shoes are worn out.

If you have any question about the condition of the shoes and drum, certainly wouldn't hurt to take a look at them.  If your coach has ever been driven with the parking brake applied (I don't know if that is possible), then the shoes could be glazed from being overheated.  Sometimes minor damage can be corrected by sanding the friction surface, but usually the best solution is new shoes.

It's been a long while since I drove cars with 4-wheel drum brakes, but I do seem to recall that the brakes were not as strong when backing up.  Something about the "single leading shoe" design not working as well in reverse.  I'm kinda foggy on that subject...well, actually, MOST subjects from that time period.  Getting old sucks.

Personally, I'd say if your coach's parking brake will hold against light throttle application in drive, then you are good to go.  Do you have to get vehicles safety tested over there prior to registration?  How do they test the parking brake?

You should carry two pair of heavy duty chocks in your coach.  If you ever have any question about the parking brake being sufficient (like on a steep hill) then use the chocks!  Better safe than sorry.
OK mate, il see what I can sort out as in pictures, I've checked those previous posts from me couple years ago, they were mainly referring to the chamber itself, which I managed to get hold of and fit, but what you said in your post about adjusting the shoes as close to the drum as possible that is what I was thinking, also the shoes are glazed which I'm sure will rough sandpaper better, and I will clean up the drum inside using a flap wheel,  the threaded. Rod that I was talking about is dead centre of the hydraulic chamber, and a clevis threads onto it, then that is attached to the parking drum brake lever which pulls the shoes on and off the drum, il try and draw a diagram of my set up using photos from manual, it's most unusual that their isn't an explanation in the manual of how to do this job step by step, just one page with a picture of the lining assembly and part no.  I can do most jobs if I have written instructions and diagrams, and that is what I am missing in manual, so wondered if anyone has the same oshkosh v815 manual as me, cause I think possibly I have one or two pages missing
1990 foretravel grandvilla, Oshkosh chassis
8.2ltr Detroit turbo

Re: How to set up parking brake on my 1990 gv

Reply #5 –
Nighthawk. Do you have juice brakes?  If so than maybe yours are the same as Kevs.
            The Hydraulic chamber releases the brakes  .  if you changed the chamber and the brake application is delayed , than maybe there is a restrictor in the hydraulics system that results in a slower escape of pressure.  The huge spring activates the shoes when the pressure drops enough for the spring to win the tug of war battle.
    The shoes rest on stops and adjusters of some sort.  When you go from foreword to reverse, the shoes rock to the opposite stop.

 So Kev . It sounds as tho the system is set up close to book, but possibly the release system has a small restriction or small tube for the fluid to pass.  I would leave it as is.

Re: How to set up parking brake on my 1990 gv

Reply #6 –
I maintained one truck years ago with them. Didn't work till cleaned and serviced. Shoes being glazed or contaminated will be a issue. Shouldn't be glazed unless someone has drove with brake set. Removing and sand blasting will not hurt. Pivot points lubed. Make sure that they are fully adjusted but shouldn't drag. If they are a spring brake possibly the spring has relaxed. Model T's had cast iron pads and they worked very well. Weird but effective.
Side note
I attempt to always chock my coach. Can never go wrong chocking anything. It is a PITA, but a good habit for me.
Scott

Re: How to set up parking brake on my 1990 gv

Reply #7 –
Quote from: Protech Racing –
Nighthawk. Do you have juice brakes?  If so than maybe yours are the same as Kevs.
            The Hydraulic chamber releases the brakes  .  if you changed the chamber and the brake application is delayed , than maybe there is a restrictor in the hydraulics system that results in a slower escape of pressure.  The huge spring activates the shoes when the pressure drops enough for the spring to win the tug of war battle.
    The shoes rest on stops and adjusters of some sort.  When you go from foreword to reverse, the shoes rock to the opposite stop.

 So Kev . It sounds as tho the system is set up close to book, but possibly the release system has a small restriction or small tube for the fluid to pass.  I would leave it as is.
That's what it feels like something slowing it down, the old chamber used to be instant, you flick the switch In the cab and you could hear the parking brake click quite loudly when the brakes were applied, but this new chamber takes approx 4 to 5 seconds and really quiet but it is holding cause when I put it into drive it won't move forward, I have took the drum off now ready to clean with a flap wheel tomorrow, and roughen up the shoes, that maybe all there is to do, there is plenty of lining on the shoes but then it's something that should never wear down because it's only used for parking, no friction whatsoever, Mike do you know if there would be a star wheel on this system for bringing  the linings as close to drum as possible without touching, cause the adjustment wear the threaded bar of chamber goes through clevis, is threaded to its maximum virtually  touching the clevis pin, so not possible to adjust anymore
1990 foretravel grandvilla, Oshkosh chassis
8.2ltr Detroit turbo

Re: How to set up parking brake on my 1990 gv

Reply #8 –
Take a peek -there should be a star wheel screw ,or a wedge , or some sort of eccentric at the end of the shoes. 

Re: How to set up parking brake on my 1990 gv

Reply #9 –
Our coach does have "juice" brakes, but also four wheel disc brakes.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: How to set up parking brake on my 1990 gv

Reply #10 –
I did some more reading (self enlightenment) on this type brake.  As Kev points out, there should be very little wear in the shoes and drum because they are only applied when the coach is stationary.

BUT, one of the drawbacks to this design is the fact that the system can develop a slow leak in the hydraulic chamber or in the hoses suppling it with pressure.  IF, while driving, the pressure in the chamber slowly bleeds off, then the brake will be gradually applied by the big spring.  The driver may not be aware of the "dragging" brake shoes until the linings are already cooked, smoking, and stinking.

Question for Kev: do you have any type of warning light on the dash to indicate that the brake is applied, other then a light bulb in the switch?  Just curious...
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: How to set up parking brake on my 1990 gv

Reply #11 –
I have worked on coaches with that system but it has been 30 years ago  so I don't remember a lot about it but think that there is a way to adjust the shoes so that they make even contact with the drum when applied. Some of the park brakes hold better going forward than in reverse.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins
 

Re: How to set up parking brake on my 1990 gv

Reply #12 –
Quote from: red tractor –
I have worked on coaches with that system but it has been 30 years ago  so I don't remember a lot about it but think that there is a way to adjust the shoes so that they make even contact with the drum when applied. Some of the park brakes hold better going forward than in reverse.
You have just hit the nail on the head, my parking brake does seem to hold better in forward, than reverse, I have removed the drum and cleaned off with a grinder with a rough flap wheel attachment, and have also roughened up the shoes which were a bit glazed, it seems to be fine now, as Mike said from protech, that it seems like it's set up OK, I can cope with a delay of 4 secs before the brake applies, like norm said, keep the foot on the pedal until applied that way, no movement to glaze up the shoes, when I flick the switch to release the parking brake it is instant no delay, the parking brake chamber is an aftermarket product made by haldex very pleased with it, and maybe it is designed slightly different so the brake applies slower for a reason, I've spoken to the mot tester, and he has said as long as it holds and the light comes on then a 4 or 5 sec delay would be OK, thanks for everyone's advice
1990 foretravel grandvilla, Oshkosh chassis
8.2ltr Detroit turbo