93 Nissan pickup front brake problems

check the pins again and it may be time to replace the flex hoses

Thanks for your reply. The pins are free. The hoses I'm sure are not as flexible as when new but do not appear to be stiff enough to be a problem. I took everything apart and cleaned all rust and lubricated. Drove a few miles without out using the brakes. Rotors were cool. Stepped on the brakes hard and then drove about 4 miles using the brakes once, gently. The left rotor is again too hot to touch and the right rotor quite warm. Perhaps since there are no release springs, if the rebuilt caliper pistons are a little tight this is normal (?). The only thing amiss is that the thin metal shim on the left outside pad is gone -- rusted away. But I can't see how that would cause the heating problem.

Your left caliper is likely seizing in the bore. Such is life with rebuilt parts I'm afraid.

I was reluctant to reply, but I had such a similar problem with my 1996 VW Transporter that I thought it might be worth mentioning.

After bleeding the brakes, I thought the pedal seemed higher - less travel to engage the brakes.

Then I found something strange. After working the brakes while driving, the pedal seemed higher still, and the brakes seemed to be dragging. I pulled over and found that one front wheel was hot. If I started out from cold, the problem didn't show until I worked the brakes seriously. All this was repeatable.

I reread my VW workshop manual, but couldn't quite believe I had a sticking caliper component.

Then I read the brakes section of the workshop manual for my Nissan, and found specific mention of the need to release the brake pedal slowly while pumping the brakes during the bleeding procedure.

I tried this on the VW, and that immediately cured the problem completely. I can't explain the mechanism.

John

Hmm, John H., that's a new one on me -- can't explain it either. I did replace the rebuilt left caliper with another one, per Jim V suggestion, and it seems OK, at least for now. I did this before I read your post. If it happens again I'll try the "slow release brake bleed techniqe". I suppose the bleed after the replacement could have been different just by accident and that might be the reason for the improvement ( ? ). Tnx all.

Also, as the pad frame & sliding pins wear, the chance of the caliper assy. becoming twisted by braking forces goes up. This would cause the inside pad to want to stick, and it would wear unevenly. If your pads are worn unevenly you may need a new pad frame and pins.