94 fullsize blazer abs problems

[jrmbrown93]

Hey I have a 1994 fullsize blazer and its having brake problems thinking the abs unit might be bad what's the difference between a 1994 blazer abs unit and a 1995 tahoe abs unit

 

[someotherguy]

Most likely a lot of difference. Prior to 1995, only the SUV's got 4 wheel antilock (4WAL); pickups got rear wheel only (RWAL). The older 4WAL units were huge Kelsey-Hayes units with an external combination valve (proportioning valve and brake warning light pressure switch.) In 1995 pickups went to 4WAL as well and it's a much smaller fully integrated unit. I am about 99% sure you can't swap them.

With that said the old style 4WAL units are pretty problematic once they get old. You didn't mention your symptoms but if it's just unexpected ABS activation then be sure your sensors and tone rings are clean. If that doesn't solve it then have the system scanned. Not all scanners can read the ABS unit. If you get a whole pile of codes related to the unit itself, it usually means it's bad. Sometimes it's just grounding issues but I think those are the minority.

Richard

 

[jrmbrown93]

The pedal is really low have replaced the master and booster

 

[someotherguy]

Adjust the rear brakes.

Richard

 

[jrmbrown93]

Just readjusted them and it jas new pads and shoes thinking the master might be bad

 

[someotherguy]

Problem was there before the new master cylinder or only after?

Lots of new master cylinders are bad right out of the box, especially if it's not really new, just a rebuild.

Richard

 

[jrmbrown93]

Before that's why we replaced master cylinder and it was a reman

 

[someotherguy]

These days a lot of people are finding when they replace a master cylinder, they have to go through several before they get a good one. Replacement parts just getting crappier and crappier. May not be the problem with your truck but it happens often enough I'd be willing to bet a few bucks on it, ya know?

Richard

 

[jrmbrown93]

Yea I mean its lasted for almost a year