98 Brake issue

[James Russell]

I have an issue that I need some help with. I have a 98 Tahoe 5.7 v8 and did a brake bleed on to but after putting new fluid in the reservoir the brake pedal would go to the floor with no pressure at all. My mechanic says it's the ABS module that's broken. Does anyone have any ideas of why this might be the reason? TIA!

 

[OR VietVet]

Welcome to the forum from Oregon.

Explain, step by step, how you did the brake fluid bleed and why. Trying to fix something or just maintenance?

 

[James Russell]

Welcome to the forum from Oregon.

Explain, step by step, how you did the brake fluid bleed and why. Trying to fix something or just maintenance?

first, opened the reservoir to the master cylinder then put new fluid in, then we tried to bleed the right rear wheel and the wheel cylinder broke so we could only bleed the three others. after we bled them and had new fluid in the lines then we went tp pump the pedal there was no pressure in the lines. Also, we tried to bleed the ABS but couldn't because the mp doesn't work and the ABS module doesn't work. I've always had spongy brakes since I brought them in the summer. replaced all the drums and disks and still a spongy pedal. So I thought it must be air in the brake lines so we bled them. doing this made it worse.

 

[OR VietVet]

Sounds like you induced more air in to the system and sounds like you already knew you have ABS problems. The brake system is the most important system on any moving vehicle. You need some new parts and have a qualified tech do it or help you. I am only assuming your bleed procedure is all wrong as well. Others can chime in but this is just IMO.

 

[drakon543]

so the wheel cylinder is bad or the bleeder broke. either way your trying to bleed a brake system using only 3 sides? little confused there so i need some further details. next up the abs system has issues have you pulled the abs fuse and or unplugged the abs module. your just fighting yourself if your trying to fix the brakes with half of it broken still trying to do something. how low did the fluid get prior to or during the bleeding. even if the abs system is inoperable and you introduced air into that part of the system you might have ***** yourself. without the abs functioning correctly you can't trigger an abs cycle during bleeding to bleed air out of the abs.

 

[Jason in DLH]

There’s a chance you can pull air in through the master cylinder if you let the fluid go below the low level line while bleeding. When you filled the MC up with new fluid during bleeding was it ever below the “Low Level” mark?

 

[exp500]

And if you pushed pedal all the way to floor M/C is suspect too. Install new wheel cylinders- Both. bleed again with a 2x4 on the floor. That is the Minimum.Gonna take 2 quarts.