What Is This Box With Brake Lines?

[zthatzmanz28]

So I have swapped out the hoses, lines and master cylinder. STILL spongey less brake.

 

What is this Kelsey-Hayes box that the master cylinder connects to? Does it have a fuse? Is it replaceable? Does it have a name?

 

Could it be the source of my brake trouble?

[zthatzmanz28]

So it is part of the ABS? the pump or something? Can it be repaired? Does ANYONE know what other models / years will interchange with the 1995 ??

[Zembonez]

What you describe sounds like the ABS system. Two things. Have you done a COMPLETE brake fluid flush and made sure you got all of the air out of the lines? Have you made sure that your rear brakes are in good shape and are adjusted properly?

[zthatzmanz28]

Rear brakes have been adjusted, I have gone through over a quart of fluid. I understand there may be a way to bleed the kelsey hayes unit or use a scanner to reset some value?

[Bowler807]

Have you recently replaced the brake pads? I have found that many aftermarket brake pads are "soft". What I mean is they cause a spongy brake pedal. The pads compress into themselves before compressing on the rotor.

 

If yes, I suggest you replace them with the genuine GM pads.

[redvett]

To properly get all ait out of the ABS module you need to use a Tech 2 to toggle the ABS module while bleeding the system. Check the FSM on the procedure.

[hayring]

I'm too fascinated by this to not pass it along: 2001 Suburban 2WD, 205+K mi.. Problem started w/calipers needing replacement due to sticking. Replaced all 4 disk calipers & pads. I also replaced the master cylinder & vacuum booster in quest for a stiff pedal. BTW, I had the Kelsey-Hayes ABS module reconditioned @ about 150K mi.. After repeated system bleeds, eventually getting solid stream w/no air at wheels, the brakes would feel pretty good, but after a day's use, the sponginess returned. Resolved that I needed to bleed progressively from MC down, I was looking for brake line ID for the ABS pump, and stumbled across a post in a forum that mentioned needing a "Scan Tool" to bleed the ABS unit. It was mentioned that the shadetree mechanic's alternative to the tool was to cycle the ABS unit manually. I drove the car onto a gravel road, and slammed on the brakes hard, thereby engaging the ABS feature. PRESTO!!!! The pedal feel immediately returned to normal. I thought air must have been injected into the wheel lines, so I did a bleed on all 4 wheels again, but got absolutely no air, and brakes have been fine since.