Suburban Brakes

[Gary R.]

We have a 1999 Chevy Suburban 2500 with a brake issue. It does has the infamous Hyra Boost power brake system.

When you depress the brake pedal, it goes straight to the floor, with the brakes activating (sorta) at the very bottom of the pedal travel.

Inspection of the master cylinder revealed a leak at the fluid reservoir, so off the the parts store for a new one. After I bench bled the new master, I installed it, and preceded to bleeding the wheel cylinders.

The pedal still goes to floor, as it did before, never did pump up.

I'm beginning to think the issue may be the hyda boost unit itself.

Any other members have this issue?

Thanks for any help, it is appreciated!

[campfire]

We have a 1999 Chevy Suburban 2500 with a brake issue. It does has the infamous Hyra Boost power brake system.

When you depress the brake pedal, it goes straight to the floor, with the brakes activating (sorta) at the very bottom of the pedal travel.

Inspection of the master cylinder revealed a leak at the fluid reservoir, so off the the parts store for a new one. After I bench bled the new master, I installed it, and preceded to bleeding the wheel cylinders.

The pedal still goes to floor, as it did before, never did pump up.

I'm beginning to think the issue may be the hyda boost unit itself.

Any other members have this issue?

Thanks for any help, it is appreciated!

Hello I work for NAPA and sounds like the hydra boost has gone bad.

[chuckster57]

I have worked on cars "on the side" for 40+ yrs and if the master cylinder leaked on the booster side, it probably took it out too.

[Gary R.]

Thank you guys, that's what I was thinking too.

I'll grab a new one from NAPA the next time I go to town, and let you know how it turns out.

[campfire]

Thank you guys, that's what I was thinking too.

I'll grab a new one from NAPA the next time I go to town, and let you know how it turns out.

Thank you for your service . NAPA will be able to help let them know you are a retried fireman may be a good discount for you

[Gary R.]

Update: Turns out the ABS unit needs bled too, and I don't have the tool to that. So we had a tow truck load it up and take it to the repair shop. The folks there had it ready for us same day, and did not have to replace anything, just the brake bleeding.

All good now!

[tech740]

I drive a 2012 Suburban 2500 for work had the same issue. It was booster after they did the master cylinder

[chuckster57]

There is a number of years for Chevy that requires a “scan tool” that can command the ABS module to bleed the brakes, yours is one of them. I forgot about that because I don’t have that tool, and haven’t dealt with that many chevys of the affected years. Glad you got it all taken care of.