1990 C1500 Brake issues

[tigerboy81983]

I have a SBRC 1990 Silverado that I’ve been having brake issues with for a while. The truck was pulling to the right when braking, and after driving a while the right wheel would be hot. I assumed a malfunctioning caliper was the cause, so I replaced both calipers. The issue persists with the new calipers and actually pulls harder now than before. Any idea what I’ve got going on?

 

[caminonut]

I had the same issue with my 90 a few years back, and it turned out to be the left side neoprene hose that go to the caliber.
replaced both neoprene hoses. Problems solved..

 

[Drunkcanuk]

X2 on the brake hose. They collapse and fluid can't return

 

[tigerboy81983]

Thanks, I’ll replace the hoses. Almost did that while I was in there already.

 

[Drunkcanuk]

Thanks, I’ll replace the hoses. Almost did that while I was in there already.

Definitely report back with your findings.

 

[Schurkey]

Calipers was a good first-guess. Didn't fix it, though. Time to investigate the steering and suspension--including control arm bushings, ball joints, steering linkage, etc.

Brake gets hot when driving? Time to disassemble, clean, inspect, and repack the wheel bearings.

Brake hoses have a bad reputation for becoming one-way valves. I've never seen it in real life. I've seen multiple brake hoses that just plugged--no flow either direction. NEVER seen one that allowed fluid one way, prevented return the other way. But I suppose there's always a first time.

Have you flushed the brake fluid? Fluid is virgin-clean from reservoir to wheel cylinder, including the RWAL?

The bad news is that you've probably got JB/JN3 brakes. Check the sticker in the glove box to confirm. The worst power brakes ever installed on a GMT400. Consider upgrading the brakes.

 

[evilunclegrimace]

Pull your rear drums and make sure that they are adjusted correctly and in good working order(no leaks or broken/missing parts). Lack out input from a rear drum brake assembly will put more strain on the front rotor/caliper.

 

[movietvet]

All of what has been said and....I hope/assume you completely cleaned the caliper slides/bolts/guides. If calipers you got came with new bolts, just make sure you cleaned and lubed everything that slides and contact points. The rotors.....did you measure for thickness and machine if needed or replace with new and clean the rotor surfaces, no matter which way you went. Brakes depend on friction, friction builds heat, heat transfers in to the metal rotors and they will warp a little at a time. Nature of the beast.

 

[tigerboy81983]

Calipers was a good first-guess. Didn't fix it, though. Time to investigate the steering and suspension--including control arm bushings, ball joints, steering linkage, etc.

Brake gets hot when driving? Time to disassemble, clean, inspect, and repack the wheel bearings.

Brake hoses have a bad reputation for becoming one-way valves. I've never seen it in real life. I've seen multiple brake hoses that just plugged--no flow either direction. NEVER seen one that allowed fluid one way, prevented return the other way. But I suppose there's always a first time.

Have you flushed the brake fluid? Fluid is virgin-clean from reservoir to wheel cylinder, including the RWAL?

The bad news is that you've probably got JB/JN3 brakes. Check the sticker in the glove box to confirm. The worst power brakes ever installed on a GMT400. Consider upgrading the brakes.

The brake fluid is new to the fronts. I did not touch the rear drums, but the master cylinder was empty when I replaced the calipers. The right side seemed to have better flow, as it dripped for days after I removed the old calipers, and it took only two or so presses of the brake to get fluid out the bleeder, whereas the left side took a considerable amount of time, so long that I stopped and checked the bleeder screw for a blockage. I'm going to replace the hoses, since they're cheap and easy, and see what happens and go from there. Thanks.

 

[tigerboy81983]

All of what has been said and....I hope/assume you completely cleaned the caliper slides/bolts/guides. If calipers you got came with new bolts, just make sure you cleaned and lubed everything that slides and contact points. The rotors.....did you measure for thickness and machine if needed or replace with new and clean the rotor surfaces, no matter which way you went. Brakes depend on friction, friction builds heat, heat transfers in to the metal rotors and they will warp a little at a time. Nature of the beast.

I did lube everything on the new calipers, and they came with new hardware. I did nothing but look at the rotors and they looked fine, but I didn't measure anything. I had thought I may have a warped rotor causing the heat. We will see what happens after replacing the lines.