I have an involuntary hobby: fixing these brakes. The van is a 1991 auto a/c 302ci V8 ford van. Though I’ve replaced everything in the system at least once with standard equipment and I removed the ABS unit, my brakes still are dangerously weak from a cold start.
I’ve bled the master cylinder and brake lines many times. No fluid leaks are evident. I adjusted the rear drum brakes so that they are “snug”, but the van still free wheels. I adjusted the push rod into the master cylinder.
The pedal seems high and hard without the engine running. After a few stops, the brakes start gripping normally or close to it.
RELATED INFO:
I’m thinking of replacing the rotors and/or the calipers again.
I recall using brush cleaner (paint thinner) to wipe the rotors clean after greasing the bearings, etc. Could this have made the rotors/pads slick?
When I replaced the flexible hose connector on the rear axle, I noticed that the brake fluid seems to enter a hole in the axle for some reason I can’t fathom. Could this be true and why? I never replaced the axle.
I can’t tow a travel trailer until I fix this. Believe it or not, I’ve been messing with this for at least 2 years. I rarely drive the van and just use it for short trips to Lowes or Home Depot.
I can’t find a repair shop that can give me other than an hourly rate to experiment with it, which I can’t afford now. I really can’t believe I can’t fix this, but I can’t.
I’ve submitted this problem on several auto forums online, but NEVER got any responses.
“Weak brakes”------- “cold start”
On loose gravel, will hard braking lock up all 4 wheels?
If the ABS unit was by-passed did you retro-fit to non-ABS specifications, i.e., proportioning valve, wheel cylinder bore dia., proper routing to all wheels, etc.?
" I noticed that the brake fluid seems to enter a hole in the axle for some reason I can’t fathom."
I think that you are talking about the rear differential vent hose, and not one of the rear brake lines.
Paint thinner didn’t hurt it. Why not get the Haynes manual and follow all the diagnostic stuff. There are proceedures for checking the vacuum booster that require no skill or disassembly. There are other troubleshooting trees that may even help.
Many aircraft don’t get fixed until a youngster gets a manual out and reads page 1 of the troubleshooting guide. You might be that guy; the one with the right idea.