Rear brakes lock up easily?

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May 6, 2013
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Hey, I just got my 90 fj62 a couple days ago and I have been fixing all the small issues with it. I have done a little searching on this subject but most people have the opposite problem. So here I am. A little history first. This vehicle has a brand new brake job from the master cylinder to the lines to the pads and rotors. Everything was replaced about 2000 miles ago. The lady I bought it from was upset because the brake pedal was mushy and the brakes still sucked. Well I don't know if the the guy who installed them didn't bleed them or if you maybe have to bleed a new brake job like that after a few hundred miles but I bled them and it feels like a brand new brake job now. The only issue is that when I get on them hard the back brakes lock up a little easily. Another issue I have and I think it's related is that the parking brake about gives me a hernia to get it to move a half inch. I'm thinking that the brakes were adjusted for the old crappy brakes and somehow this adjustment translated to the new brakes in the rear. If I am right a little info on how to adjust them back would be great. If I am wrong and there are other things possibly wrong a couple things to troubleshoot would be nice. Thanks everyone.
 
I haven't dealt with drum brakes since I went with a rear disk brake conversion so I cannot comment on your main issue.

As a side issue I would look at your Load Sensing Proportioning Valve (LSPV). If your LSPV is not working or manually zip tied in one position then you could be getting full brake force to the rear when your truck isn't loaded with gear which would cause skidding in the rear. It may be the main issue but I cannot say as I don't work with drums.
 
Ok, that makes sense, I will go take a look after lunch. Hopefully it's not because that would tell me it's not working and somebody just rigged it. Am I wrong to assume that the parking break tension has something to do with this?
 
My friends 40 does that. i drove it in the rain and that thing was allover sliding its ass everywhere when i got on the brakes. in dry conditions it wasn't bad at all, would still lock the rear wheels if i got on the brakes hard but the big issue was the wet stuff. would lock up right away. i don't know if he ever looked into the problem, since he never drives the darn thing.
 
Yeah, it caught me off guard the first time it happened, I hit them on the pavement and I got a little squeal out of the rear. I kinda expected that because I was checking them after I bled them. I let my gf drive it and told her to get a feel for it, only this time we were on gravel. Needless to say she almost rolled it on my 2nd day owning the thing.
 
This happened to me on a 1970 Nova....Hit the brakes...backs locked up and I slid right through the intersection...front brakes had failed. The fronts on any front engine vehicle do most the work due to the engine weight being over the front axle. When the fronts stop working, the backs are asked to do more than they can to bring the vehicle to a stop and just lock up right away. (and do little to stop forward progress)

So failing fronts or drastically mis-proportioned.
 
I really don't think it's the front brakes that are failing they are coming on hard for sure. Before I bled the brakes that's what I thought might be the case, but when I bled them I notice there was virtually no air in the rear brake lines and the fronts specifically the front left had most of the air. Obviously that air was affecting all the brakes but the brakes are good it just seems to me that the rear brakes are too good. Damn you'd really have to drive it to know hat I mean but if I could just back them off a bit somehow it would be perfect. It's not that I haven't driven a car without abs brakes before but not in several years, maybe the problem is just me. I have put about 100 miles on it since I bled them and there are no noticeable leaks or anything either.
 
The weird e-brake thing has me wondering if the e-brake is set to tight and thus still partially engaged when you are driving. This would translate to you stepping on the brakes and having them lock up like that.

Time to go through the system, re-adjust everything and re-bleed everything. Make sure that you are doing the bleeding in the proper order (which for a 62 I believe is LR, RR, LPSV, FL, FR). Might be good to pull the pads and shoes to ensure there is no weird wear and then go from that point.
 
How are the drums? Id mic. The drums and see if they are still in spec. Check rear pads to see if they are swollen , Could rear seals be leaking on to pads. Mike
 
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Between adjusting your park brake and the LSPV you should solve your problems. Check that the park brake bellcranks are free and not keeping the shoes from relaxing.
 
Uh oh, I bled the right rear first, that is how I've always done it. I bled in this order rr lr fr fl. I thought you were supposed to start as far away from the master and work your way to it. Hmm, I loosened the parking brake and I just don't want to go around slamming on the brakes so I'm going to see how she drives for a few days and slowly continue to troubleshoot it. I didn't bleed the LSPV either, now I have to re do that thankfully it's and easy usually rewarding job.
 
Uh oh, I bled the right rear first, that is how I've always done it. I bled in this order rr lr fr fl. I thought you were supposed to start as far away from the master and work your way to it. Hmm, I loosened the parking brake and I just don't want to go around slamming on the brakes so I'm going to see how she drives for a few days and slowly continue to troubleshoot it. I didn't bleed the LSPV either, now I have to re do that thankfully it's and easy usually rewarding job.

You are correct, you should start as far away from the MC as possible, but it is line length you're concerned with.
 

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