Another puzzling brake issue
Wow. I have been reading some of the threads and now my problem seems small.
I will set this up with a little history first.
Brakes dragging only on the right front, Most of the time. :embarrass
This is a 1976 Dodge B200 Van, 318cu, auto, power brakes.
This also sat for almost three years out in the elements. (I know, I should be horse whipped)
Been replacing belts, hoses etc and had done the brakes not too long before I parked her.
Started driving her again, pulling and moving some of my boats from up in Washington down into Oregon.
First trip down to Oregon, I noticed, Wow, I just did a tune up and might need to pull the carb off and go though it as the mileage is bad now too.
The van was loaded heavy and the boat on the back was also loaded pretty heavy. Pulled into a rest stop and didn't seem to notice any issues stopping, other than I had to dive on the brakes pretty hard.
Going back out on the freeway, I noticed her shaking like I had a tire coming apart, belts broken and getting ready to blow out.
Felt the tires, no, all round and hard, no bulges?? Felt the hub and the right front was Hot, too hot to hold on too.
Left side was fine.
Now that I am on the freeway, I need to get off at the next exit I think so I head out again and same vibration and all of a sudden, it starts to go away.
Then I notice, its gone, no vibration at all.
This time I kind of roll off the side of the freeway and use next to no brake peddle to stop, felt the hub and it was even Cooler than before.
After about two or three hours on the road, I forget about the problem as it went away.
(I don't believe in self healing either)
Then a few days later, no load in the van, going over to a friends house, it starts that whole thing over but only this time, I don't remember having to Dive onto the brakes to make it happen.
I was able to get it off the road, put the jack under it and the left wheel, I could turn with the standard amount of resistance for disc brakes. The right side, I was not able to turn the wheel.
I parked it, ordered a new master cylinder for it, did the bench bleeding, check the dept of the plunger as I know they can be different, but it was the same. What I did not do was check the hole size.
Bolted on the new master, jacked up the front wheels and gave them a spin and both felt fine.
After a few days of driving, it all started happening over again.
Here is what I have done up to this point.
I pulled the master loose and checked the hole size and made sure I had the same clearance as I did with the old one (it worked fine for 5 or more years before parking it)
Made sure the plunger was all the way back, still had the right front brake hanging.
Check the vacuum booster for throw as well as fluid that may have leaked in over time, all clear, nothing hanging up or catching.
Pulled the right front wheel and used a large screw driver in the fins to spin it. Its still hung up.
Pulled the two bolts that hold the anti rattle and hold down braces in place.
As soon as those anti rattle plates were moved, I did see that I was able to mussel the caliper and make it move by hand so it was not hung.
So, the question that I am wondering about. Does a 1976 Dodge B200 (1/2 ton) Van have a Limiting valve? on it?
I did see a block on the left side, top of the frame were it looks like only the brake lines go in and out of. No wiring or centering valve that I could see.
Now, because I was Stuck with it out of town were it happened to me, the only thing I had to purchase was a cheap 6 inch "C" clamp to compress the piston on the caliper.
I was able to just pull the wheel, compress it about 1/4", pump the brake peddle back out, compress, pump it back out, compress, pump it back out.
The brakes are working like they should, again, for how long, no clue...
So, here I am, stuck away from my shop and not sure what parts I should go for.
Hmmm!! You will first have to figure out if the problem is at the wheel, or either your master cylinder or proportioning valve.
Right off the bat, I'm ruling out the master, because only one front wheel is locking up.
Here's what I would do !! Carry a wrench with you that fits the bleed screw. Next time your front right wheel locks up and you can't turn the wheel by hand, loosen the bleed screw to releive and pressure that MAY be built up.
If after doing this your wheel is still locked, then you know you have a bad caliper.
If the the wheel gets loose, then It can only be a bad flex line or proportioning valve.
I myself would change the caliper first. I had a LF brake hanging on my 96 GMC 1500 and it was the caliper. When you changed the master and when you bled the brakes, was the fluid clean looking or was it discolored? Are you positive all the air is out of the system?
Change all your brake hoses, sounds like a classic hose coming apart on the inside, acting as a check valve
Caliper with a problem?????
If the vehicle had been sitting for 3 yrs i think that is your first clue and points to a semi - stuck caliper piston imo. When you say you pulled the piston in about 1'4 with a clamp and then pumped it out again a few times , i think that is when you freed up the piston a little. We did my sons old volvo a while ago which was heating up one front wheel and found the rubber boot that covers the caliper piston was split which allowed rain water in . This allowed a rusty build up of sludge between the piston and caliper cylinder. We had to battle to get the piston out. Once we cleaned it out it was fine. We polished the piston and cylinder with 800 wet and dry. We even used the same piston seal as the edges were still okay. This worked for us. You never know, it may work for you.
My '98 Dakota had stuck calipers in the front. This started after having a "shop" remove the lowering kit I put on it (right after buying it new) due to my bad back. Right after, we went for a drive and after returning, smelled what I thought was burning wires. Wife saw smoke coming from the RF wheel and the wheel was too hot to touch. Found one caliper bolt was stripped causing the caliper to c0ck and lock against the rotor (I thought?). Fixed that with an oversized bolt and all was good. A month later, we made a 250 mile round trip and halfway there, the other side did the same thing. Went to another shop and the guys found the LF caliper not releasing, but couldn't find a reason for it other than dirty fluid (both bolts were fine). They sanded the pads and we got home without further trouble. After changing the pads, calipers and resurfacing the rotors, I flushed 2 QTs of fluid through the entire system and it all seems to be working properly for now. Bottom line: check the fluid quality, mine was filthy with black gritty "stuff"...
No air is in the system as the peddle is rock hard. Rear brake adjuster could use some cleaning so it works better, which means the peddle is a little lower than it should be is all.
But hey, it did set for quite some time out in the elements. Salt air to boot.
My rotors were new the last brake job (which was not too long before I parked her) but have hot spots in them. If I can find someone that will "Grind" them and not just condemn them (these new trained mechanics need old people to tell them, How it was done before all this new machine crap designed to Make them Money showed up). Plenty of metal on these rotors as they are pretty new.
Also, what is the theory of operation behind the proportioning valve mounted on a disk/drum system anyway ??
I need to clear that one up.
I see a block on this old girl but, is it a distribution block, or really a proportioning valve I wonder...
How would I tell without dissembling it?
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