I've been having this problem for awhile, but it seems to be getting worse. When I step on the brakes, my pedal goes halfway to the floor, but if I pump, it becomes real firm on the second pump.

Also, when I've slowed to about less than 5 mph, I'll get a little ABS noise and I can feel a little pulse in the brake pedal.

Anyone have similar problems? Does it sound like ABS unit or brake booster?

thanks,
Ken

 

You may have air in the lines... Try bleeding your brakes and see if that fixes it.

 

If you do not have someone who is able to help you bleed the breaks, look into getting some speedbleeders. I just ordered mine the other day.

 

Can you see any leaks under the car? If no, then it's most likely your ABS unit or the master cylinder. If air was in the lines it wouldn't get firmer after pumping, it would have a continues spungy feeling.

-J

 

I guess I should have given more info originally. I have experienced this before and after I upgraded to the 929 master brake cylinder. Also bleeding makes no difference. The pedal becomes very firm after 1 or 2 pumps. I'm sure it is either the ABS unit or the booster, but I'm just wondering if anyone knows before I go spending money . I'm starting to lean toward the ABS unit though.
Thanks!

 

Did you bench bleed the 929 MC?

 

I have the same problem with being spongy on the first push. I was thinking it was just some flexing and I needed some stainless brake lines.

 

check your fluid levels... my money is there's air in the system. bleed it and get back to us.

 

Did you address the recall that locates the one-way check valve to the other vacuum hose?

 

Yes, I performed the bench bleed on the 929 master cylinder at install.

I have stainless steel brake lines.

I just installed new brake booster hoses with check valve.

Fluid levels are fine, I've bled the lines numerous times.

I'm almost ready to pop for an ABS pump to see if that cures problems.

Thanks!

 

1funr1 i was just wondering do you have a bigger picture of your sig?