Lisa N Greg Highsmith

I just bought a 1994 blazer and am having some issues with the brakes. When I first apply the brakes for normal stopping it will jerk to the left extremely hard but after a split second it will straighten out and come to smooth stop. The person I bought it from just replace both front calipers and pads. The brake pedal feels real squishy like it is air in the lines. I flushed the fluid and bled the brakes and the problem persists. I pulled the brake hose off of the right side and tried putting a new one it but since it has 8 inches of lift I found out I have to special order a new one. I blew through the old one and had plenty of air passing through it so not sure if the hose is bad or not and it is a steel braided hose so I heard they do not go bad often. When I bled the lines I had plenty of pressure on all of the lines except the right front line and had very little on that one. So I am guessing it is blockage in the metal line from the master cylinder to the brake hose. My question is where to look if the new metal line and hose does not fix it when I get it in. I wouldn't think it would be the master cylinder since all of the other brakes are working fine.

tech2

if the new flex hoses do not change anything...do a suspension check and make sure there is no play in the ball joints, steering linkage, control arm bushings. any play will cause a directional change when you brake.

Lisa N Greg Highsmith

So I have traced the blockage to this but I am not sure what it is. I thought it was an ABS control modulator but when I look that up to see how much it costs it comes up with something different. Can anyone tell me for sure what the name of this is. I know that when i break the lines loose going into it from the master cylinder I get plenty of fluid pressure but when I break the line loose going from this box the right front brake caliper I get very little fluid pressure at all.

tech2

its the electronic brake control module and brake pressure modulator valve...also known as the abs module and pump.

any abs codes?
so when you check the l/f outlet from the pump, its good?

Lisa N Greg Highsmith

Yes so I checked the line coming out of the master cylinder going to that electronic brake control module and had plenty of fluid and then checked the line coming out the electronic brake control module going to my caliper and had very little fluid coming out.
No codes at all

tech2

with a scan tool, do a abs pump autobleed procedure