94 C-1500 ABS system

[big2bird]

So I'm doing a brake job on a 94 Chevy C-1500 truck with ABS today. The right front caliper is dragging REALLY bad, but the hose was just changed. I figure it's the caliper or hardware hanging up. I started with draining the system out the bleeders, like I always do. As soon as I pop the hose on the right front, the pads loosen right up. The master is open, because the reservoir bled right out. Is there a residual valve in these systems?
There might be a obstruction in the old caliper, but this kinda has me stumped.

 

[69427]

So I'm doing a brake job on a 94 Chevy C-1500 truck with ABS today. The right front caliper is dragging REALLY bad, but the hose was just changed. I figure it's the caliper or hardware hanging up. I started with draining the system out the bleeders, like I always do. As soon as I pop the hose on the right front, the pads loosen right up. The master is open, because the reservoir bled right out. Is there a residual valve in these systems?
There might be a obstruction in the old caliper, but this kinda has me stumped.

Is this a 4W ABS? (My '93 1500 just had the rear wheel ABS.)

 

[big2bird]

So I'm doing a brake job on a 94 Chevy C-1500 truck with ABS today. The right front caliper is dragging REALLY bad, but the hose was just changed. I figure it's the caliper or hardware hanging up. I started with draining the system out the bleeders, like I always do. As soon as I pop the hose on the right front, the pads loosen right up. The master is open, because the reservoir bled right out. Is there a residual valve in these systems?
There might be a obstruction in the old caliper, but this kinda has me stumped.

Is this a 4W ABS? (My '93 1500 just had the rear wheel ABS.)

Yes. This AM I found some tin foil, no doubt from a brake fluid can seal, at the bottom of the reservoir circuit in question. I am going to replace the master, and power flush the whole system before adding the slaves.
I believe firmly the foil worked its way down the system. perhaps scoring the M/C lip seals as it went. I can even see some foil debri stuck at the M/C intake.:suicide:

 

[big2bird]

Is this a 4W ABS? (My '93 1500 just had the rear wheel ABS.)

Correction. Yes. Traced the lines. The modulators only affect the rears.
Changed the M/C, pressure bled the system, and am still getting slight bubbles out the reservoir. The rears actually came up fast. The fronts, PITA.

 

[clutchdust]

there should probably be another section of threads devoted to why you don't let someone else work on your vehicles. bubba strikes again!

 

[mrvette]

Is this a 4W ABS? (My '93 1500 just had the rear wheel ABS.)

Correction. Yes. Traced the lines. The modulators only affect the rears.
Changed the M/C, pressure bled the system, and am still getting slight bubbles out the reservoir. The rears actually came up fast. The fronts, PITA.

Is it a disc/drum or 4 wheel disc???

 

[big2bird]

Is this a 4W ABS? (My '93 1500 just had the rear wheel ABS.)

Correction. Yes. Traced the lines. The modulators only affect the rears.
Changed the M/C, pressure bled the system, and am still getting slight bubbles out the reservoir. The rears actually came up fast. The fronts, PITA.

Is it a disc/drum or 4 wheel disc???

Disc/drum