ABS pressure modulator replacement

[dewberry]

A few months back I had posted that my pump crapped out on me after replacing the throttle cables. Took it to two dealers and both claimed it was just a conincidence that my pump went out just after replacing the throttle cables. My bike being an '02 R1150RS I found a used pump from an '03 R1150RS which according to the online microfiche have the same pump(34 51 7 685 790). The number stamped on my pump is 34 51 7 660 909 N5237P and the used pump I purchased has the number 34 51 7 663 755 E5287. There is a subtle difference between the two but are they interchangeable?

Just out in the garage working on it and the original pump works for the rear brake but not the front. If you tap the rear brake you can hear the pump change tone the front does nothing. The pump is quiet until you hit the brake then it continues to make noise after the pedal is released. Don't know whats going on anyone have a clue.

Bob

[T__]

Bob, have you put a meter on the brake switch to make sure it actually works when you release the brake pedal.. Or,, once the pump is running after you release the pedal disconnect the switch to see if the pump then quits or keeps running.. Sounds a lot like a sticking switch or lack of FULL pedal return even though the pedal is released.. There is a switch to pedal relationship & gap setting in your service manual (might be worth a check)..

 

Twisty

 

[dewberry]

It seems to me that both switches are opening and closing because the tailight does switch on when either the front or rear are actuated. I just replaced the pump with a used one I found. Now I need to bleed the system. Is it normal for the pump to be running after the key is turned on? Don't need to touch the pedals it is running just after you turn the key on. I will check the gap in the rear switch. I now need to find the link to bleed the system.

Twisty thanks for your help!

Bob

[Ken H.]

Is it normal for the pump to be running after the key is turned on?

For a second, yes. Continuously, no.

[Dave Faria]

Give Bob's BMW a call. They have always been free with their knowledge. Dewberry, if you like your bike and plan on keeping it consider the GS-911 by Hex. It can read the faults and clear them on both the EMCS and the IABS unit. They are presently doing a Beta test on software that will also read dynamic information. Ted Porter's "The Beemer Shop" is the USA rep. When I got mine(over a year ago) it cost $199 for a unit that would interface with a laptop and $249 for one that would interface with both a laptop and Bluetooth. Are you near Austin,tx??

 

Dave Faria

Austin, Tx

[dewberry]

Dave, thanks again for the input. I do plan to replace this bike with an R1200GS come spring. I am located in Central Cal, near Modesto. Now that the "new" pump is intalled I think I am going to trailer it into the dealer for bleeding. Is it possible that the faults just need to be cleared since it is a new pump? Going to check the rear brake switch as well. Once the key is turned on it does not go through the diagnostic and then become quiet. The pump stays on from the moment you turn the key on, with or without the pedal/lever depressed.

Bob

[Dave Faria]

Bob sorry can't be more help. But, maybe the pump not shutting off is a good sign. It may be a self check for pressure - just a guess. In any event don't let the pump run dry. The brake fluid lubricates and cools the pump impeller. BMW is like Obama - keeping his cards close to his chest on how it is going to work.

 

Take Care and good luck