I am looking for some help on my 2000 S10 Blazer LT. I install new brake pads all the way around. I found that the passenger rear was down to pure metal. I replaced both rear disk assembles. The brakes when tested worked fine but after about 15 miles I was shocked when the brake pedal went to the floor and I had no brakes and the red idiot light came on for brakes not abs. After pumping the pedal, I had brakes the light went out and the blazer rolled. The next time I used the brakes the pedal again went to the floor the red light for brakes came on and I again pumped the peddle got brakes and the light went out but this time the brakes stayed on they did not release. I was close enough to home to drive it home.
Today I pulled all wheels off. All calipers were out. The fronts were retracted with use of c clamp without any resistance. The rears were frozen.
What could cause this (master cylinder) (ABS) (Bad Fluid)?
How do I fix it?
Thanks
laser770

 

generally the idiot light is triggered by pressure drop between the front and rears sensed by the proportioning valve
After you did the fronts did you pump up the the pedal slowley half pumps until the pedal hardened up before driving ?
After pushing the calipers all the way back you need to pump to close all the gaps back up

Is the fluid still full ?

Did the ABS pulse with pedal failure ?

 

On these rear disc brakes, it's best to replace the calipers, brackets, hardware, pads & rotors at the same time. The caliper pistons are steel, the housing is aluminum, brake fluid is hygroscopic, meaning it attracts moisture, which causes corrosion. During the life of the rear brakes, the caliper bores corrode so when you push the pistons back in, the corrosion causes the pistons to bind up and or destroy the seal.

Before removing the caliper, line lock the flex line near the caliper. After the new caliper is installed, top off the master cylinder, leave the cover off, open the bleeder, release the line lock and let the caliper gravity bleed until there are no bubbles present, and the fluid comes out clear. Make sure the master cylinder does not run dry during the gravity bleed. Slowly push and slowly release the pedal until firm. Then bleed each caliper while holding pressure on the pedal, don't pump it. Usually only takes one, maybe two times.

 

@ Captian

I just peformed a rear brake replacement(both sides-calipers with clips, screws, screw seals, high temp grease on floating screws, rotors and ceramis pads) using one of your previous posts gravity bleed and partial depress bleed until no air. Master never dry, cap off during gravity bleed for 10 mins.

How do you recomend "line locking"?(making sure i didn't skip/miss something) plus i am looking at replacing the brake lines with steel reinforced lines.

Also having problems with the rear brakes making a burning smell(not smoking), going to give it some time since its new brakes with brake silencer on metal contacts(not pad to rotor). But if the rear calipers are locking up, what would you recomend or did I miss something maybe?

 

+1 on replacing all the rear parts.caliper,pads and rotors.Did that yesterday on my 99 Blazer.Parts are cheap.My calipers were lifetime warranty,so they were a swap,rotors $32 each and pads $22.About 4 hours time because the old rotors fought me.Used a Mitey vac to pre bleed and than pressure bled to finish.

 

Something like this works well:
KD Tools Hose Pinch-Off Pliers 1-1/4 in. OD Capacity - Tools - Mechanics & Auto Tools - Automotive Specialty Tools

The purpose is to keep the fluid from draining out of the line while the caliper is being replaced, this keeps bleed time to a minimum.

Possibly the park brake cable is stuck causing a drag??? Or it could be a restricted flex hose, or a binding caliper piston.

Should never use any silencer goop or anything like that on the pads. The factory doesn't use it, totally unnecessary, huge waste of time and money and makes a mess. Don't use cheap pads: Use Raybestos, Wagner or Bendix. Take 'em out of the box and install them. If you're using new, (or rebuilt) calipers, new clips, lube the guide pins, and have a good non-directional finish on the rotors, they will not squeek or drag.

 

After driving it to work today and checking it periodically, I have concluded it was just a new brake wear smell. I pulled the brakes back off and did not observe any glazing or premature wear.

I did not observe any glazing on the parking brake shoes either.

On the brake silencer grease, I have to disagree with you Captian. When I worked at a GM dealership(Pontiac, GMC, Saturn, Buick, ETC) I recall a bulletin on the use of silencer grease for a certain vehicle(granted not the blazer). For the purpose of parts settling when they first make contact. Example would be as the piston on the caliper first makes contact with the pad, it allows the piston to better settle into an initial "flush fit" and disperse the pressure across the entire piston/pad as well as allowing the movement of the pads into an equal position. Thus preventing uneven wear.