Parking brake shot

[class87]

From: Winnielover4078  (Original Message)
Sent: 11/5/2005 7:38 PM

My driveline parking brake does not hold anymore, as I'm sure alot of yours may be the same way. I had an idea and wanted some opinions before I acted upon it. A few years back I drove an old school bus with hydraulic brakes that had a hand actuated parking brake as are winnies do, but the school district also added a valve on the dash with a knob you would pull after pushing down on the brake pedal. I guess it holds the pressure in place and keeps the brakes applied. J.C. Whitney sells such a system for twenty something bucks, I dont park on hills very often, but once in a while I like to park it in my driveway to work on it and would like to have something to help hold it on the hill. Thanks.....Kenny



From: denison
Sent: 11/5/2005 8:44 PM

I believe the hydraulic parking brake valve is okay for brief periods, like ten or 15 minutes; but for any extended period of time, there is likely to be some 'bleed-down', eventually leading to the vehicle beginning to glide downhill.
I presume your winny has the small parking brake mounted on the end of the transmission? I had to get mine relined, and to replace the parking brake cable. The cable was sticking, would not release the brake shoes, and they would have burned out the first day.
Getting that parking brake drum off means dropping the driveshaft, starting at the rear axle. Once the driveshaft is out of the way, there is a large nut holding the drum to the end of the transmission tail-shaft. The drum and the shoes were very hard to remove, but take care of them, I dont know that there are any new ones available. If you want to remove the brake backing plate, be very careful in pushing the pin sideways that holds the large rod to keep the brake backing plate from turning. You can split the aluminum of the tailhousing if you hammer on it.
If you have the drum off and can get to the rear transmission seal, it would be a good idea to replace it if you can.
When I park in my (slightly sloped) driveway to work on it, I have the handbrake on, the shifter in park, and I put wheel chocks on both side of the wheels that I am not working on. 



From: denison
Sent: 11/5/2005 8:46 PM

Correction; I meant to say the drum and brake shoes were NOT very hard to remove. A dirty job though.



From: cooneytunes
Sent: 11/5/2005 9:37 PM

I was told by an old mechanic who works at a GM dealer (he's 67 yrs. old) has been a mechanic all his life... and it was confirmed by the guy who owns the NAPA store near me....that you can still get the shoes for the parking brake, but you would have to have them with you to match them, Part numbers won't cross over to anything made right now. Some Midas Muffler places still do re-lining....and almost any custom motorcycle shop that makes special cables for bikes can make a new brake cable...that would have to be removed and the little balls on both ends matched along with the length. Or you would have to find one in a junk yard....I found a cable and hand lever, the guy wanted 60 bucks..I passed on it.....I believe that one your talking about from JC Whitney is a ratcheting lock (which holds the brake pedal down) similar to what is on most farm tractors....only problem with that is you would have to have a switch to disconnect your brake lights, or move the circut to come on only with the key... 
I have a 1988 Ford 600 School Bus with Hydraulic brakes, the parking Brake works off the Hydo-boost System....Next to the power steering pump, it has a seperate resevior for Power Steering Fluid only ....which then is connected to the Master Cylinder via high pressure hoses....works well, but very hard to trouble shoot when there is a problem, because it uses an electric motor to help create vaccum to push the PS fluid through the Master Cylinder...I think it was Ford's answer to try and make air brakes out of Hydraulic system and out do Dodge on the Hydro-boost...They only made the system for a few years..It was a little to complicted for most, very expensive to work on poth parts and labor.....Master Cylinder rebuilt is about 750 bucks...
Dodge Engineers Laughing at the system... Priceless...If you can have it fixed.... get it fixed...in my opinion it was one of the best parking brakes ever made....this side of air brakes..... even once it's fixed...still continue use wheel chocks.

Timmy



rom: Winnielover4078
Sent: 11/5/2005 10:56 PM

I was wandering myself if the valve would bleed down, my biggest concern was having pressure on the wheel cylinders for an extended period of time, I didnt know if it would affect them in the end, brake problems are the last thing I want! I will see what I can do about getting the parking brake fixed properly. The cable is in great shape and moves perfectly, but the pads are wore out. Even though Vegas is a large city, it is very hard to find competent help here, many shops are the here today gone tomorrow type.....Kenny



From: M300-413
Sent: 11/8/2005 6:32 PM

Just finshed restoring mine. The cable was realy stretched.. I found one from a guy who bought out old Mopar inventories. He knew what he had and charged me $90 for it. Ouch! the good new is it works great now.
The rear friction material also had broke loose from the metal part of the shoe. It seems the transmission rear tail shaft seal had been leaking for a long time and soaked the material which likely cause it to come lose. Friction Materials of Essex MD 800-543-4223 did a nice job of relining the shoe for about $45 with shipping.
If any of the clips or hardware is damaged that holds the shoe in place your in trouble unless you can find something in a bone yard.
I don't have any experince with a "hydraulic hold" type parking brake, but would be interested if you have any sucess with that!