Bleeding brakes on a 97 Tahoe.

[kobuzz]

Trying to get pedal pressure on a 97 Tahoe. Had a rear wheel cylinder blow out and lost fluid. Installed new wheel cylinders on both back brakes and new front Disc pads. Bled brakes like I have done for last 25 years and couldn't get any pedal pressure. Installed new master and re-bled 5 different times and still no pressure. Goes to the floor. Any ideas? Only thing I am not familiar with is the Tahoe has a hydro boost brake system. Is there a different method I need to use to get pedal pressure? The brake pressure was fine before the wheel cylinder blew out. It is not leaking fluid anywhere so I doubt air is getting back in the lines. Bench bled the master and also gravity bled the whole system.

[NoClassic]

I would suspect an issue with the ABS module.

[BP]

Is it a diesel? That's the only one that should have hydroboost. The brake circuit is pretty much exactly the same regardless though. It'll either have a vacuum booster or a power steering fluid adding pressure behind the master cylinder.

You should find someone with a Tech2 or ABS test software with a comparable scanner and use it's bleeding function. It can be done without a scanner but it's a pain in the ass. You'll never get it bled properly without bleeding the ABS modulator.

http://www.aa1car.com/library/abs_bleeding.htm

[kobuzz]

Sorry for the late reply but it turns out there is a valve on the ABS module you also have to bleed. Got good brakes now. Thanks for the help!

[4EyedTurd]

Good to know, is that something you need to do on all abs cars?

[BP]

Good to know, is that something you need to do on all abs cars?

Generally speaking no. Most ABS systems run on a separate hydraulic circuit that only connects to the regular brakes when activated. So if you replace a caliper, master cylinder or other normal items you only need to bleed the affected circuit. If you somehow managed to activate the ABS with a massive leak though you may need to.

[4EyedTurd]

Thanks