T5Mika

I managed to let air into the RF-LR ('01 vert) brake circuit when changing the fluid and the reservoir ran too low.

I flushed 1/2 gallon of fluid through the system with the Motive bleeder and did the abs bleed with tech 2. But the pedal was spongy at a cold start and the brakes were pulling. I bled the brakes again, and the same story. After a few heavy brake applications the pedal is firm again and all corners are modulated by the abs. The LF-RR rotors are hotter by about 50 degrees after heavy braking, so there's gotta be air in the system yet.

What am I missing? I thought I knew how to bleed brakes, but I must be doing something wrong.

racebum

if air is introduced into the system you have to get it out of the abs. if you have a tech 2 you can cycle and bleed, if you don't you sometimes can do it by bleeding, going for a drive, pounding the brakes into abs, going back home, rebleeding and repeat till you're good.

50deg is not a really large temp diff by the way. i'm guessing you ran the brakes to 500-600deg?

you can also try driving if it's close, go 1k miles and retest, see if the air has worked its way out of the abs and either into the lines or master. in other words, drive and rebleed after a month of driving

Tomm1011

Jack up and put rear on jack stands. Start engine ,put in gear and accelerate to 11 mph. Because front wheels are not turning traction control will activate, bleed brakes and refill mc. A couple of trys should do it. Worked for me.

T5Mika

I would think that the tech 2 abs bleeding is better than tricking the traction control. I can try it though.

Cutlassmaster

Did you remove master cylinder and bench bleed it? If you had air in it and did not beanch bleed it, could still be some in it.
Chris

Meta

Yup, that'll do it. You have to bench bleed the master cylinder if you run it dry. No other way to get the air out.

Ray 2000 C5 FRC

LMDNC5

Tech 2 ABS function bleed is the way to go or any scan tool with ABS capabilities.

lionelhutz

It doesn't sound like you have anything to worry about. Keep driving it.

racebum

it's basically the same thing only the tech 2 is much more efficient. so many things can cause a 50deg variance you may be completely fine. just the shape of the road can do it when more weight is on a tire than another. also i hope you're talking 50deg left to right front to front, rear to rear. if you're comparing front to rear the numbers are meaningless

T5Mika

Another tech 2 bleed and a huge air bubble out of the LR caliper. Now left to right brake temps are even and the brake balance is good. It just seems to take a few bleeds to get all the air out after farking it up.

racebum

it certainly can, i've experienced similar with, multiple rebleeds, driving awhile then rebleeding. doing what you did. really isn't fun

c51stvette

Clueless here, what is a tech 2 brake bleed?

racebum

it cycles the abs similar to what happens when you pound the brakes. if air is in the system it often hangs up in the abs and you either have to tech 2 bleed or bleed, drive, bleed, drive repeat until the air is gone. by drive i mean pound the brakes so the abs lights up