mushy brakes, firm brakes, mushy brakes...wtf??

[Mike 92 XLT]

My brakes are acting really strange. Sometimes they will feel great, with a nice firm pedal and very linear action, and some other times, the pedal is really mushy and the brakes don't engage until the pedal is close to the floor. The fronts and the rears have both been recently replaced, as has the master cylinder. The strange thing is, it behaved the same way with the old master. Did I get a bad new one? Or is there air in the lines someplace? The brakes always work fine, it's just the pedal feel that varies.

peace

Mike

 

[flatlander]

It sounds like you have air in the lines to me.

 

[JoeC5]

yeah, I agree with flatlander. You probably have a lot of air in the lines. Bring it back to the place where you got the brakes done and have them bleed it for you free of charge. They should do it right the first time.

 

[chrisb87]

If air was in the lines then the brake pedal would go damn near to the floor every time. With what u wrote the brakes were acting this way before replacement of the rotors, pads and brake master cylinder and reservoir, tells me right off the bat that air in the brake lines is not the culprit By a long shot. What it does tell me is that your vacuum hose going to the brake booster needs to be inspected and replaced and if that doesn't do the trick ( which probably wont) the brake booster is failing or has failed altogether and will only work partially after things warm up and the seals inside the brake booster that are shot have expanded. Its a very time consuming job cause the dash will have to be pulled away from the firewall to be able to remove the old one and to install the new/ refurbished one. I see now that this was posted in 2001 so if anything take this for future reference If this problem happens again in any vehicle that you may own with the same problem