[dmtnt]

When replacing the master cylinder, obviously you're going to get air in the lines. I've always heard that introducing air into the line going into the ABS unit is bad, but not sure why. Is there anything special I need to do (i.e. Tech II bleed) or can I just bleed the crap out of it to get the air past the ABS unit? Thanks.

 

[GNX Guy]

Bleed like you would any other car. No problems for me doing it that way on my car and several others I've done work for.

Joe

 

[GSMZ06]

You can also "bench bleed" the new master cylinder to minimize the amount of air introduced into the system.

 

[2K3ZO6]

I just did the bleed/ABS flush last Thursday. I had Sean at LG Motorsports flush the ABS with the Tech 2 tool. The service manual says to use the Tech 2 tool to open the solenoid valves, when you have the system drained. Its about 75 bucks not including fluid.

It appears from the other posts that it seems to work without the Tech 2 proper method.

Ask yourself this, are you comfortable going into that hairpin turn off the main straight at 140MPH+, THINKING i got all the air out of my brakes?

I know that 75 bucks lets me sleep a whole lot better.... Brakes, tires and steering is not the area to cheap out. MY .02

 

[dmtnt]

Thanks for the input guys. When I first purged out the crappy stock fluid a long time ago, I had it bled with a Tech II to make sure any stock fluid in the ABS unit would be purged as well. My question is whether or not air can be introduced into the ABS block from replacing the master cylinder and whether or not it will just bleed out normally.

 

[2K3ZO6]

I wouldn't think it would induce air into the ABS. BUT, have said that, I have heard my ABS unit making that groaning sound when I was doing a caliper bleed. I think the groaning sound is the solenoid valves actuating.

You will have codes in the system that will need to be cleared anyway. (Low brake fluid level)

 

[Subdriver]

Dmtnt,
Probably the technically correct answer is to get a tech II bleed...

That said, I rarely have time to do that. While I haven't had my master cylinder out, I have had the ABS block out several times for various motor pulls, which probably gets you to near the same point. After such an evolution, I bleed the system thoroughly then drive it easy and active ABS a few times to cycle the solenoid valves. Then I bleed again. After that I take it easy my first track session, normally a warmup, and then bleed again.

:cheers: