ABS Flush???

[volavet]

I am going to have my brake fluid changed. The speciality shop I am going to take it to says they flush the whole system to get every bit of fluid out and flush the ABS system clean, rather than the normal dealer simply draining the fluid. However, another shop told me that is a bad idea, and that you are asking for trouble flushing out the ABS system. Any comments or advice you can give me would be appreciated. I do not want to hose up the uber expensive ABS pump which went on my VW and cost $1800 for the part alone.

Thanks.

 

[1stC3Vette]

Are you changing the type of fluid or just flushing the system with the same? If the same, I would not mess with the ABS. There have been too many posts about spongy brake pedal feel that may be ABS related.


Good luck,
Dino

 

[PLRX]

I flushed the system before, slowly and one caliper at the time. The ABS is a microprocessor, leave it alone. Once driving on the desert the computer activated the ABS over 15 times and magically it ended having a firmer brake pedal. Was this an ABS bleed? I will never know but it did it. You do not need a shop to flush your brakes, get a 12 pack and knock it off yourself. Have Fun

-Pedro

 

[c4cruiser]

To flush the ABS system, a Tech II with the brake module is needed. That allows the service tech to run the ABS pump so that the new fluid is passed thru the ABS unit. When I had the fluid flushed on my 92 for a track day a couple of years ago, I went to the dealer and asked to have the ABS flushed along with the regular flush and they did not recommend doing the ABS. I aked why and was told that there is a risk of getting air pockets in the pump lines and even spilling fluid in the compartment. The pump has a bleed port on the side of it but it's not like a bleed valve; there's no easy way to hook up a drain hose.

Everytime you start the car and move forward, the ABS does a self-test and that energizes the pump and fluid will flow between the pump and the master cylinder reservoir. When the ABS is activated in a braking situation, the pump runs and some fluid moves. So normal operation of the car will move fluid thru the pump. Once you flush the lines, drive the car a couple of days with a half-dozen engine start/stop cycles, then use a turkey baster to suck most of the fluid out of the M/C reservoir and refill with fresh fluid.