TOUCHY brakes

[chris015]

87' r10. power brakes. discs on front.

Picked it up and its been sitting.

if you BARELY press them on a roll up to a redlight etc the back driver side wheel locks up. I picked up front pads,and calipers. Pulled the drum off everything looks fine. no weird wear. they need to be adjusted a tad tighter,but thats it. No leaks on cylinders. No rust.

Rear center hose has been replaced at one time,some idiot used vice grips and rounded the head off. Ive got a new hose but,i dunno if i wanna change it now or not.

Im wondering if the front calipers are about seized as truck sat up for some time. lil pad left on front too. maybe a worn proportioning valve? checked the reset thing in it,it wasnt flipped. Any help is nice. Im no noobie. Just brainstorming on this. Master cylinder looks to be somewhat new.

[donut]

My brakes tend to get grabby if it's been sitting for a couple months, usually it'll clear up pretty quick. Then again, I know the condition is good as they've all been rebuilt (within last 200 miles.)

Brake parts for a 1/2 ton are relatively cheap, so keep that in mind.

When you pulled the rear drums, did the shoes move freely?
Was the adjuster free?
E-brake functional, (this could have an impact on the rest of the rear brake function.)
What shape were the drums in, any scoring, pitting, heavy rust?

You kinda jumped around with your problem. Left rear was locking up, then your wondering if the front calipers are seized. I'll help where I can.

Calipers can seize up. (lost one over a summer while I was rebuilding my old truck.) You have to collapse the caliper anyway if your going to change shoes... (I've got a large C-clamp I use, I also unclip the master cylinder cap and leave the cap on loose.) If you want, try them out and check. I usually leave it on jack stands, put a wheel back on, spin it, and see if it stops ok. You'll be able to see if the piston moved to put pressure on the pads.

I honestly don't think I've ever HAD to replace a prop valve, and I've owned a bunch of sub 500.00 beaters.

[chris015]

yep pro valve is a last deal thing.

im thinking the fronts are about seized,causing the back to work harder. the rears fine. clean,no rust,grooves or pitting etc. I will be redoing to front tomorrow. i guess il post back then.

[chris015]

Havent heard back from my buddy at the shop,but i just reread what you posted. I do know the ebrake goes to the floor with ease.

[donut]

I was thinking if the cable was rusted up, it could "adjust" the rear shoes tighter.

If it were me, too many variables and sketchy items. Brakes are one thing I like to work properly.

[chris015]

noticed your in Sc as well. upstate?

[donut]

York, moved from Maine about 4 yrs ago.

Hey, do yourself a favor, do the hoses if your going to do the calipers. The ones on my '86 looked fine until I moved them.

[chris015]

gotcha. im south of greenville.

As for the hoses,the passenger side front has been replaced at one time. looks fairly new. driver side looked original. the rear center looks old,but some moron got ahold of some vise grips and went to town on the nuts,and now they are rounded off. i picked up a front left,and a rear one.