1995 Silverado Z71 Brakes

[zthatzmanz28]

We just replaced our rotors, front pads, rear shoes and master cyclinder.

 

After bleeding the brakes the pedal is spongy and still travels almost to the floor. The vehicle stops but there is no pedal left.

 

Hmmmmm. Do we need to look at the booster or could it be the hydroboost unit? How can we tell which part is causing the sponginess and save ourselves the cost of playing musical part replacement--if that is possible. Truck has 190K miles.

 

THANKS

[StoneyPgh]

Did you bleed the master cylinder first before connecting the brake lines? If not, that's probably your problem and there is still air in the lines.

[r1byker]

Did you bleed the master cylinder first before connecting the brake lines? If not, that's probably your problem and there is still air in the lines.

 

+1. That's usually done before it's even installed on the vehicle. If you did do that, then you've still got air in the lines and you just need to keep on bleeding until you get it all out. Did you start at the farthest wheel from the master cylinder first? Good luck; I've gone through almost a quart of brake fluid when bleeding and that was on a Honda Accord.

[zthatzmanz28]

Started farthest from master (passenger side rear) went through nearly a quart of fluid. Pedal is fine when truck is not running, but once started the pedal is mush...master cylinder was leaking into booster.

[xrbeav]

So did you find your issue? Or was it the booster?