Cobra4B

Just curous.... I'm guessing even after bench bleeding the master there will be a little air in the system from connecting the lines.

If I bled the fluid through the calipers then wouldn't air go into the ABS and not come out?

Must I take it to the stealer and get a Tech II bleed?

davidfarmer

no, not usually. Unless the ABS module is active when you bleed it, the air bubbles should just float on by.

Cobra4B

Oh... awesome

astock165

I took my m/c off two winters ago to change the bias spring and clean out the reservoir. When I put everything back together all I did was bench bleed the m/c and then bled the whole system. Everything seemed fine.

As long as you don't let the calipers drain and you get a good bench bleed on the new m/c you should be fine.

Aardwolf

When I changed the M/C on mine I left the lines just barely cracked at the master. Then had someone slowly press the brake pedal so a small amount of fluid was forced out, I closed the lines before the pedal got to the floor. I figured some air may have got there while hooking up the lines.

davidfarmer

let me clear up, you will get air into the lines, which must be purged, but in my experience, the bubbles will NOT penetrate into the EBTCM solenoids unless to run the entire system pretty dry. A full (ie several bottles) bleed is necessary to clear out the system, but I've not had a problem with bubbles getting into the abs valves.

Worse case, if you have a spongy pedal, you find someone who has a TechII after the fact. Brakes will work with bubbles, just not as effectively.

2000BSME

has anybody said to bleed in the opposite direction to avoid this problem?

If you get air in the lines from replacing the master cylinder, push the pots into the caliper futher to bleed the air back into the resevoir.

Problem solved.

Kinkajou

Unfortunately I had to do this job several times because of master cylinder going south.

Service manual suggests that after bench bleeding the MC, install, then start by bleeding the ABS that is located in the rear compartment behind the drivers seat.
Then right rear , left rear, right front and finally left front .

It is time consuming but I did it using a Mighty Vac, I found it to be very usefull, just have to keep an eye on fluid level.

If this does not make it right you might have air trapped and maybe need to repeat the procedure or use the Tech 1 to redo the procedure.

2000BSME

I like your screen name, I just rented a series of Japanese anime, called Samurai 7, with one of the characters called Kinkajou, but I doubt that's how you came about your screen name.

rbl

Has anyone tried introducing new fluid from the caliper BACK to the MC? We do that with the airplanes and it pushes the air up easily and completely eliminates the air. Not sure if it will work on the Corvette w/valves???

2000BSME

see post #7.