98 Blazer - rear brake problems

Local shop "flushes" the brake system and replaces rear pads. Drive vehicle home, brake pedal soft. Return vehicle to shop following morning, pick up that afternoon. Brake pedal now firm, but vehicle seemed sluggish. By the time I get home rear brakes very hot and odorous. Call shop and they say that pads have to seat, but will improve after a little use. Drive car all weekend and no improvement.

Back to shop on Monday morning and they now say that I need two new rear calipers. When I asked how both could fail simutaneously, they can't answer.

I went by the shop and car was up on a rack with both rear wheels off. I went back to take a look at things and found that I couldn't turn either of the rotors by hand.

Suggestions????

Local shop "flushes" the brake system and replaces rear pads. Drive vehicle home, brake pedal soft. Return vehicle to shop following morning, pick up that afternoon. Brake pedal now firm, but vehicle seemed sluggish. By the time I get home rear brakes very hot and odorous. Call shop and they say that pads have to seat, but will improve after a little use. Drive car all weekend and no improvement.

Back to shop on Monday morning and they now say that I need two new rear calipers. When I asked how both could fail simutaneously, they can't answer.

I went by the shop and car was up on a rack with both rear wheels off. I went back to take a look at things and found that I couldn't turn either of the rotors by hand.

Suggestions????

When a wheel is dragging remove the caliper bleeder screw.
If the drag stops or goes away it is brake fluid pressure build up.
If it still drags with bleeder open it is caliper or mounting slides drag.

If brakes are dragging there is a reason and usually do not improve with driving and may drag more with driving.
To the point of burning up the brakes.
I would find another or a good brake repair shop.
Good Luck and let us know how it bgoes.
MT

The 98up rear single piston rear calipers always need to be replaced at each brake job due to the piston being a composite plastic that distorts slightly so after being pushed back in usually gets cocked or jams in the bore and the brakes are on - all Blazer owners 98up just don't waste your time and when you do the rears buy "loaded" brakes - caliper rebuilt, new bracket with greased slides and seals, and pads about $55 so do it right and spare yourself the pain!

One thing I didn't cover in the first post was that the tech mentioned opening one of the bleeders and draining some brake fluid off. He said after that the rotor spun freely. That makes me think that the rear caliper pistons may not be sticking.

If that is the case, what would be causing the rear portion of the brake system to stay pressurized? If the system was flushed and the equalizer valve was not centered (and held in place) would that cause the calipers to pressurize and not release?

Thanks

One thing I didn't cover in the first post was that the tech mentioned opening one of the bleeders and draining some brake fluid off. He said after that the rotor spun freely. That makes me think that the rear caliper pistons may not be sticking.

If that is the case, what would be causing the rear portion of the brake system to stay pressurized? If the system was flushed and the equalizer valve was not centered (and held in place) would that cause the calipers to pressurize and not release?

Thanks

Muddog321 has some good advice on the rear caliper.
If opening the bleeder relieves pressure.
The master cylinder or abs if equipped or a rubber brake hose could be bad.
When pressure is dragging on it open the line ahead of the rear brake rubber flex hose to test the rubber flex hose.
If still pressure on caliper with it loosened up the rubber hose is bad.
If that relieves pressure go up to abs unit or master cylinder and open rear brake lines.
Let us know how it goes.
MT

Muddog hit the nail right on the head! ALWAYS replace the calipers, brackets, and hardware every time rear brakes are done on 98 and up S/T series. Any technician that has at least half of his marbles should know that. The reason both calipers developed a problem at the same time is because when the caliper pistons were retracted, (to make room for the new pads), they dragged debris back into the caliper bores with them. The first time you apply the brakes, the pistons extend bringing the debris with it. That debris is what causes the pistons to bind in the bores. When pads get hot enough to smell, they're hot enough to crack the friction material. Look closely for cracks and replace the pads if you see any. When friction material cracks, it's life expectancy is greatly reduced.

Hats off to MT, Muddog, and Old Master.

After replacing both rear calipers, the brakes worked just fine. The shop said they replaced the pads at the same time, so I'll take them at their word. I don't think they were trying to get next to me, just not real familiar with the intricacies of this particular brake system.

Thanks again guys for your invaluable assistance.