Soft Brake Pedal

[90Gmc]

On my GMC I have a very soft brake pedal its like 3/4 to the floor and it finally

 

stops I have had new brakes, new lines that have been bled and still the problem.

 

They have even been adjusted and still the same problem wut could this be? If this happened to any one else please write or if you know ho to fix the problem.

[elgineddie]

Howdy,

Do you have vacuum booster or the hydro booster brakes? My 2001 has the hydro booster and the brakes were getting very spongy even after I put new rotors and pads all the way around, changed the fluid to the Blue Racing stuff and bled em all out. I couldn't figure it out. Then my power steering pump took a crap which basically took the power out of my power brakes thanks to the dumb hydro booster. After the power steering pump was replaced, the brakes were nice and stiff... like new!

 

Hope this helps. If you don't have a hydro booster all I can think of is flushing the old fluid out and bleeding your system. If that don't do it I think a master cylinder rebuid may be in order.

 

Ed

[az'03Silverado]

My '03 Silverado C1500 is the same way. If you look at the size of the brake lines, though, and also consider the 4-wheel disk brakes with two-piston calipers, you'll notice that the brake system has a lot of volume so the pedal will go farther than on an older truck with drum brakes in the rear.

[mhraracing]

Howdy,

Do you have vacuum booster or the hydro booster brakes? My 2001 has the hydro booster and the brakes were getting very spongy even after I put new rotors and pads all the way around, changed the fluid to the Blue Racing stuff and bled em all out. I couldn't figure it out. Then my power steering pump took a crap which basically took the power out of my power brakes thanks to the dumb hydro booster. After the power steering pump was replaced, the brakes were nice and stiff... like new!

 

Hope this helps. If you don't have a hydro booster all I can think of is flushing the old fluid out and bleeding your system. If that don't do it I think a master cylinder rebuid may be in order.

 

Ed

Hmm.... My buddies 01 Dually Dmax has the same spongy brakes. He did all the same stuff and still cant figure it out. I never thought of the power steering pump. I will let him know about yours.

 

Thanks!!

[Metz Motorsports]

I had the same problem on an older Tahoe. New pads, shoes, calipers, the whole nine yards with no improvment, ended up having the brake fluid flushed and the problem was cured. Weird how that works.....

 

-Jason

[NOS#9BIGMAC]

my 90 GMC brake pedal goes 1/4 to 1/2 way down but my fluid is dirty as mud. gotta flush it this weekend but they don't feel spongy pretty firm actually. I'm to drunk to have any Ideas....burp

[90Gmc]

Would it work the same because I have drums in the rear.