Bleeding your brakes with AST.

[lkwd318ti]

Hey everybody,
I was reading the Bentley manual, and they were saying not to bleed the brakes if a car has AST and/or ABS.
They said "bring it to an authorized BMW dealer."
Do I really have to do that or can I just bleed them normally?
How do you guys do it?

Thanks in Advance.

-Randy

[1996 328ti]

You can bleed your brakes anyway. Just be sure that the reservoir doesn't run dry. There is a way to cycle the ABS pump so you get all the fluid out. You remove a relay and short two pins. I could look it up if anyone is interested. I've been getting my brake fluid flushed 3 times a year for 8 years and have never had a problem.

[cali-ti]

if you could look it up, that'd be great. i personally would like to have that info.

THREE times a year? wow. is that because you track it?

[1996 328ti]

THREE times a year? wow. is that because you track it?Yes. I have them bled after my 2nd or 3rd driving school, depending on track and weather conditions.

I had posted it to bf.c. :)
I HAVE NEVER DONE THIS but this is how my previous independent shop did it.
Remove the ABS relay closest to the firewall and fender and short pins 30 and 87. This will cycle the ABS. I guess the ignition needs to be in the on position. Never let the system run dry.

[lkwd318ti]

I'm planning to do a full fluid flush on my car.
Do you have any tips?
As usual, this site is always helpful.
thanks alot again.

-Randy

[track3d]

Get a pressure bleeder! $45 at www.trackhaus.com

Worth every penny!! I used mine last week on a 97 Nissan and the pedal feels like new again.

[316i compact]

I am going to change brake fluid as well, i'll change from Motul DOT4 to RBF600, and i need some help on how to clean the system from the old fluid, before filling with the RBF600!

[Mallard]

what happens exactly if the system runs dry?

[tastade]

I think the best way is to buy (or make) a one man bleeder (or have a friend help) from a car parts store, about $5 to $10. It is just a bottle and a hose that you hang above your brakes. You attach that to the bleeder bolt as instructed, loosen the bleeder bolt (don't remove), and go pump the brakes a few times, add fluid to the brake resevoir and drain the bleeder bottle as necessary. Never let the brake fluid in the resevoir run low (then you don't have the whole ABS problem).

You repeat this at every corner until all the fluid runs clear. Retighten the bleeder bolt after you are done with the corner. Run in this order: back right corner, back left corner, front right corner, and front left corner (work your way closer to the brake booster). The one man bleeder prevents air from entering the system through the bleeder bolt, if you don't use a bleeder you should run the hose off the bleeder bolt into some brake fluid. Make sure to try out your brakes before driving anywhere.

[mohaughn]

Pumping the brakes with the bleed screw open doesn't really work. Each time you release the brake pedal the fluid will get sucked back into the caliper.

The right way to manually bleed brakes is the open the bleed screw. Push the pedal down. Close the bleed screw. Release the pedal. Repeat.

I still think the easiest way to change brake fluid is with a mity vac hand pump. This way you can crack the bleed screw, and apply a vacuum at the bleed screw to pull the fluid out. The only downside is that, unlike a pressure bleeder, you need to check the reservoir to make sure it does not get to low. I think I paid 15$ for mine from Sears.

[tastade]

Pumping with the bleed screw open works fine if you use the one man bleeder, it prevents it from being sucked back in, I had no trouble getting my brake fluid all clear. Your method sounds easier though if you have someone to monitor the fluid level.