OK. Let's try this again. A month after replacing rear brake shoes, I found out that only the rear parking brake works. The master resevoir is full and there are no leaks. I tried to manually bleed the reear hyraulic lines, but no fluid would come out. What's wrong here?
What's wrong??? Well, we have no idea what we're working on... that's part of what's wrong....
If you are doing the bleeding right, either the master cylinder is bad or the lines/wheel cylinders are plugged up.
-- Elbridge Gerry, of Massachusetts:
"What, sir, is the use of militia? It is to prevent the establishment of a standing army, the bane of liberty. . . Whenever Government means to invade the rights and liberties of the people, they always attempt to destroy the militia, in order to raise a standing army upon its ruins." -- Debate, U.S. House of Representatives, August 17, 1789
Uh, yeah--sorry about that. What we're working here is a Ford Explorer, EB model with 2WD, 91 vintage (bought in May 90), color: black. I also changed the front disc brake pads at the same time, BTW, and they are working fine. I don't recall ever adding brake fluid to this vehicle.
First guess is bleeder screws plugged off with mud/debris.
This is derived from age, etc..... Another possibility would be siezed cylinders but these *should* allow fluid to flow through the bleeders. Another concern might be due to siezed brake cables.... if the shoes don't contact the anchor pin, the linkage geometry is gonna be bad and this can give poor brake performance.
Thanks to you and AZGuy for the tips, Jim. I unscrewed the bleeder nozzles and checked them for dirt/corrosion. I also checked to make sure braked shoes were seated properly. Couldn't find any problems with either. What would you think about taking vehicle into a shop and having the whole brake system bleeded on a pump and the fluid replaced? Wouldn't that reveal exactly where the problem was? Also, did this model year (91) come with rear-only ABS? Seems to me I recall hearing that, or was it just hot air? Regards, Dave
Our 92 has rear-only, and I believe the 91 had that too.
Taking the truck to a shop to have the brakes bled won't find where the problem is, but it will give them an opportunity to find the problem. After all, you're bleeding the brakes, right? Did you find where the problem is? No. Finding exactly what's causing the problem is, IMHO, a good idea. If you can't do it, then take it to someone who can. Driving without rear brakes is, um, what's the word? DANGEROUS. That's it. When you couldn't fix the problem yourself, you should have taken it to a shop you can trust to have it fixed.
Bill Funk Change "g" to "a"
RABS was the flavour of the day, back then, but all it could do was to allow the fluid to enter an accumulator. Even if the RABS valve were leaking, you should still get something out of the rear bleeder screws.
I can only suggest using the power of elimination....... start at the master cylinder and work back... This is the same technique that you would pay for having a shop do this.
MC appears to be dual ciruit with two lines out. Don't know how to test this mc for proper operation. Unless I can find simple test procedure soon, I'm throwing in the towel and taking vehicle into shop tomorrow. Will post results afterward.
I have a '91 and had this problem last year. It was the RABS valve located on the frame a little forward of the fuel filter. I verified by 1) testing I got fluid from the master cylinder and 2) testing I could not get fluid out the RABS valve. I tried to clean and unstick the valve but no joy - I could send compressed air thru it but not fluid. The valve was a little pricy - I think I recall about $300 US. Searching the web widely, I found a few other reports of the valve blocking fluid.
You don't have to buy this part new. There are numerous salvage yards on the Internet that will sell that part for less. There are two modules to the RABS system, one electronics module underneath the dashboard behind the climate control cables, and the external hydroelectronic one that is mounted on the frame rail. I got the diagnosis from Ford that the interior one was bad, and I was looking for $200 part, $300 labor charge.
I searched the internet and found a source who had the part I needed, and backed it up with a money-back guarantee if it was DOA. It wasn't, the part was $45 plus shipping, and the REAR ANTILOCK warning light hasn't stayed on past the starting circuit test since.
Regards,
Richard
Wally Brechtelsbauer wrote:
-- Elbridge Gerry, of Massachusetts:
"What, sir, is the use of militia? It is to prevent the establishment of a standing army, the bane of liberty. . . Whenever Government means to invade the rights and liberties of the people, they always attempt to destroy the militia, in order to raise a standing army upon its ruins." -- Debate, U.S. House of Representatives, August 17, 1789
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