Spongy Brakes

[GLFloyd1]

I have a 2000 Silverado 1500 replaced calipers, master cylinder, and ABS Pump/Modulator. Bled all four calipers. Brake pedal spongy and has very little pressure and travels all the way to the floor. What am I missing here?

[MT-2500]

Originally Posted by GLFloyd1

I have a 2000 Silverado 1500 replaced calipers, master cylinder, and ABS Pump/Modulator. Bled all four calipers. Brake pedal spongy and has very little pressure and travels all the way to the floor. What am I missing here?

May need better bleed out.
Like pressure bleed and scanner ABS bleed.
How did you bleed it?
Any abs codes or fluid leaks?

[GLFloyd1]

Thanks MT 2500.. I took it to two separate shops. There are no ABS Codes. Not sure what method they used to bleed the lines. I am baffled!!!

[j cAT]

Originally Posted by GLFloyd1

I have a 2000 Silverado 1500 replaced calipers, master cylinder, and ABS Pump/Modulator. Bled all four calipers. Brake pedal spongy and has very little pressure and travels all the way to the floor. What am I missing here?

they/you need a scan tool GM abs controller . this is used to bleed out air trapped in the ABS valve module section. also you never push back the calipers with the bleed screw closed. if you do this can happen.

another reason for spongy brakes is worn rotors and pads. too much piston extension will cause a soft pedal and harder stops. the less fliud in the calipers pistons the better the braking ...

2000 SIL. 5.3L 4X4.

[GLFloyd1]

Where can I find one of those GM scan tools? Is it easy to use?

[MT-2500]

Originally Posted by GLFloyd1

Where can I find one of those GM scan tools? Is it easy to use?

Round up 3 to 5 to 10 grand$ and start asking around at tool dealers
Or go to a good repair shop that has one and pay them a hrs labor to do it for you.

[j cAT]

Originally Posted by GLFloyd1

Where can I find one of those GM scan tools? Is it easy to use?

I forgot to say make sure you have no leaks. these vehicles have defective brake lines with rust issues. these lines fail in the rust belt after 5 years. the inspection of these lines can be hard. the line running to the rear rusts out next to the fuel tank so check that area. any small leak will cause your problem.

[cbenslay]

Originally Posted by j cAT

they/you need a scan tool GM abs controller . this is used to bleed out air trapped in the ABS valve module section. also you never push back the calipers with the bleed screw closed. if you do this can happen.

OK, I have changed my brakes pads for years and I've never opened the bleed valve when I've used a clamp to push the piston back. I was never taught that! Is that new since we have ABS nowadays? That may explain my spongie brakes on both vehicles! Is there anything I can do now besides have them bled at a brake shop somewhere? Is there a code I need to look for.

I was searching for "master cylinder" because I thought that was the issue...

Thanks,
Chuck

j cAT - No need to respond. I just read your bleed procedure on another thread. Thanks!

[phipps]

I have never opened my bleeders when pushing the pistons back in and have never had a problem.