Hello,
i have a P-30 with the 19" wheels and it is leaking brake fluid but only for the rear brakes - the fluid level never drops for the disc brakes up front. There is some oil on one of the rear drums on the inside and the local mechanic i go to sometimes said it is probably the wheel cylinder. He said i will need to replace both of them, plus grease seals and axle gaskets and also diff fluid and of course brake fluid (dot 5) and it he would charge about $170 for the labor. He is a good mechanic and always seems to have reasonable rates, but i just don't have any more money to put into the van for the moment especially since it is not leaking that bad, at least not yet - so for now i will just have to keep buying a pint of brake fluid every couple months and add it.
But i would like to eventually fix this myself when i have time. I have a GM service manual but can't find how to do this procedure in the brakes section. All i know is you have to remove the wheels and the axle but i don't know what else.
do you have to take the entire drum brake assembly apart?
could anyone explain how involved this process is and if there are special tools needed?
Also, if anyone knows where in the service manual this is explained i would like to know.
I have fixed just about everything on this van but the rear axle is one of the only things i have not messed with and i don't know much about it. Any help greatly appreciated!
thanks,
Paul

Your mechanic is right, you might better replace the brake shoes too. From your discription the wheel cylinders are seeping right now but it is going to get worse. Its not a hard job, you may have to remove the axle to get the drum off but other than that it is the same as any drum brake set-up. Lay out the springs and do one side at a time so the other side can be a referance point.

Lay out the springs and do one side at a time so the other side can be a referance point.


can you tell me what springs you are talking about? The brake shoes are pretty new and still have at least 50k left so i don't need to replace them. Do i still have to take the drum assembly all apart? Any special tools needed?
thanks
Paul

Try taking a look at this its very basic but might help
http://auto.howstuffworks.com/drum-brake.htm

This pic is from an explorer but yours will look nearly the same, you can buy hardware kits from napa if you need new springs. Also if the shoes are soaked in brake fluid there junk, I've seen shoes come apart and get stuck in the drum causing the well to lock up

http://www.explorerforum.com/data/3364/medium/18205Drum_brake_WEB.jpg

Yes, you'll need to remove the hardware to replace the cylinders. If your mechanic is only going to charge you $170 plus parts, I say have him do it because the parts are cheap. It's not hard to do, just can be a PITA because the drum/hub combination is very heavy.

You should also make sure to replace the brake shoes because they will be saturated with brake fluid. If you do it yourself, be sure to use DOT 5 like you mentioned. The P30 van chassis needs the high temp stuff.