Brake bleeding trouble, 95Qa

[aaronl]

Ok, I commited the sin of sucking air into the master cylinder when doing a brake job and flush. Yes, I do have the FSM and am following the FSM procedure.

I have used almost 2 quarts of new fluid flushing and bleeding. I am not getting any air out of the calipers any more. I "flushed" the fluid in the TCS resivoir by sucking it out with a hand vacum pump then refilling and starting the engine, at least 6 times.

My problem is that I continue to have to bleed the TCS. Over the past week I have done this maybe a 100 times. I open then close the TCS bleeder, engine off. Start engine, run till TCS light goes off. I do this till I see no bubbles when opening the TCS bleeder. If I pump the brakes many times or drive the car for several miles, the SLIP and TCS lights will come on (I can hear the pump cycling). TCS code is 18. Bleed the TCS again and all is ok until I drive and pump the brakes a lot. I don't see any leaks in the system. The fluid levels don't change (except when opening the TCS bleeder).

Yes to all of you that will say "tsk tsk you &%#* up". I know that. What do you think I need to do now? I have read all the posts that have "Bleed" and or"brakes".

Thanks, aaron

Modified by aaronl at 2:54 PM 3/10/2007

Modified by aaronl at 2:54 PM 3/10/2007
Modified by aaronl at 2:56 PM 3/10/2007

[Q45tech]

We use a BG brake machine which pressurizes the mastercylinder and has a giant res of brake fluid feed to master cylinder under pressure and vacuum the fluid out at each bleed port sequentially [manually change ports]...............this could be used on ABS and TCS ports.

[qship96]

except the 94-96q dont have abs bleeder ports!

[Q45tech]

You can always add ports if you desire.............another cost saving deletion on 94................actually the way ABS works you are less likely to get bubbles there than in TCS.

The newer integrated models are even worse you need a Phd to get them back to normal if abused by air bubbles.

Believe me we would have not spent $3,000 for a brake flush machine that was unnecessary, nor 3 Consult II @ $7300 ~~$22,000...........why our labor rate has gone to $85 just to pay for new equipment.............we have another $30,000 on the wishlist.

[aaronl]

Thanks for the replies guys. I think I am getting closer after another day and 10+ cycles of bleeding the TCS. Pedal feel is better and TCS/Slip lights didn't come on after the last two drive tests.

Has any one tried a slow gravity bleed on a Q?

Thanks, aaron

[maxnix]

You can always add ports if you desire.............another cost saving deletion on 94................actually the way ABS works you are less likely to get bubbles there than in TCS.

The newer integrated models are even worse you need a Phd to get them back to normal if abused by air bubbles.

I thought you had said a Consult is necessary to activate the ABS unit to cahnge the fluid.

If so, how could new fluid with air bubbles get in the ABS in a straight brake fluid replacement?

[aaronl]

Original post was on the 11. One full week of bleeding the TCS morning and evening about 20 times and I have all the air out.... I was begining to think I had to be sucking air with out leaking fluid some how. But eventially with patience, I finaly have good brake feel and and the TCS pump doesnt run when I start the car.

aaronl

[Q45tech]

It scares me that members might not be as diligent as you were in correcting the problem. Especially that generic mechanics would leave the job half done as 20 bleeds x $85 is a high price to pay to get it right.

We see it all the time where customers come in from other shops with air in systems from the stress of $99 brake jobs.

Actually expensive brake flush machines save labor [don't need a helper]and but minimum wage people are expendible vs our $20-$25 per hour technicans.