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I'd say your beast is bled out.

However, check out post #3 here.

If that doesn't get it I would probably throw in the towel and get a used hydraulic half from Adam (Clemster).
 

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Discussion Starter #62
Can I, Should I, take the hydraulic half off and clean the passageways and poppet valves? Or have it rebuilt locally or get a used one from Adam (Clemster)?



I am guessing that if a valve is stuck open, or closed, the fluid will move through the hydraulic half and back to the reservoir allowing the brake pedal to travel to the floor (not allowing full pressure to the calipers)?



Any advice is helpful here...
Thanks!!!
 

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Yes but not on this model. Did it to an E34 540 I had, but then stopped pushing fluid back up and never needed to do it again. Not sure I figured anything out, but it set the stage for figuring out the vanos when I got my E39 M5. I usually have a spare parts car, and in my E34 days I had 3 or 4 so swapped parts for diag.
 

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So MAJOR success on my side! Indeed turned out to be the hydraulic unit half of the ABS system! I was able to determine this conclusively after I got plugged in with INPA. While cycling all of the ABS valves, got to the left-rear outlet and. . . no clicking!!! Removed the electronic front part and hooked it up to my spare unit and ran through everything again and all valves clicked properly, so then I went ahead and opened the lines, swapped in the good hydraulic unit, re-bled everything, and now brakes work properly again! Posting here in the hope this helps someone, key point being it was easy to hear which valve was non-functioning when cycling all of them in INPA!
How did you go about cycling the ABS with INPA?

These are the options that I have. Does it look the same for you? If yes, which sequence do you follow to activate the valves - first intake RR, exhaust RR, then RL, etc... ?

 

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Discussion Starter #67
How did you go about cycling the ABS with INPA?

These are the options that I have. Does it look the same for you? If yes, which sequence do you follow to activate the valves - first intake RR, exhaust RR, then RL, etc... ?




That is a question I would like the answer too also. When I did mine from this screen, I assumed one would have a power bleeder connected, pressurized, bleed nipple open and work the corresponding vents, etc... for that nipple. Can someone confirm this. I had search the web high and low for instructions on this and for other parts of INPA.
 

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Discussion Starter #68
I have been pondering what my next step should be to get to the bottom of this brake pedal to the floor issue.


It seems that there must be air in the system that allows the pedal to go way down. I don't know if the DSC hydraulic valve block is at fault (valve stuck open or close). When I use INPA to activate all the solenoids, I do hear them click and the pumps pump. I would like to send the whole DSC unit somewhere for testing, both the electronics and the hydraulics as an assembly. Can anyone suggest such a shop in the USA for this?


If not, I am thinking I should separate the electronics from the valve body and try and open it up. I would be looking for sludge and anything that would prevent free movement of the valve pistons trap air. Has anyone opened one up? Any info/tips?


What about re-bleeding the DSC to remove all air and the whole system once it is reinstalled?


Any information would be a big and much appreciated.
Thanks!!!!!!
 

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Discussion Starter #70
Have you inspected the pump?

I have not other than activating the two pumps and hearing them run. But please tell me how this is done and what to look for in order to determine if the pump is good or not. Details and pix or where to find them would be very helpful.


Thanks!
 

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To answer some of those questions, what I did was as follows, although it took a while:
1.) Run pump
2.) Activate intake valve for a given wheel WHILE helper pumps pedal and I bleed at the wheel.
3.) Run pump again
4.) Activate outlet valve for same wheel WHILE helper pumps pedal and I bleed at the wheel.

For some reason I wasn't able run the pre-load pump at all, but I think that would make bleeding very easy. Also not entirely sure this is the 'correct' procedure, but I assume that flipping the valves while pushing fluid through the system must clear most of the fluid through there, surely. I also hear a little bit of squelching from the ABS unit when pressing the pedal, so I think I probably have a little more work to do there myself.

In other news, while I was redoing the whole front suspension on the new car I also installed SS brake lines as well as the bronze bushings for the caliper sliders. The bronze bushing kit was poorer quality than I was hoping and gave me lots of trouble to get right (new SS pins would not slide freely in the bushings even before I installed them on the calipers and required LOTS of sanding/deburing to get proper action), but with everything done on the front now my brake feel is again considerably better, so I guess it was worth it. But I would caution anyone considering the bronze bushings to THOROUGHLY inspect/rework them before committing to installing them!
 

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To be honest it sounds like you checked everything , it was a final thought on things that people tend to overlook. There is a compressor pump, that sits near the horn where the drivers sides fog light is, it has weird conditions on when it activates first start(maybe) vehicle speed ect so it might explain why it just appears after a while. Anyway I'd check and see if you see any fluid coming from it.
 

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The two companies that come to mind are Module Masters and BBA Reman. I'm sure there are several others. You might call them and explain your issue to see if they can help. They need to know you don't have the trifecta lights.
 

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Discussion Starter #74
I just removed the drivers side front panel and I see the Compressor, DSC. I went through INPA and activated all of the 'pumps' listed while sitting next to the Compressor, DSC. I did not hear or feel any activity from it. I checked the ABS/ASC fuses (10, 21, 38) and they are all good. Are there other fuse(s)? Which one/where is it? What would turn it on so I can make sure it works?



Looking at this Compressor, DSC where the hard brake lines go in, one is marked HZ and the other is BA. Can someone tell me which is fluid in or out? I want to put the Power Bleed on and crack the outlet hydraulic line to bleed it. Should I do the same to the six lines going to the DSC Hydraulic Unit?


I would like give the above a shot before removing the DSC Hydraulic Unit and sending it to BBA Reman. They said they can test the electronics and the hydraulics together as a unit to insure All is working as it should.


Thoughts and opinions welcomed!!!!
 

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By WDS the fuses are 30 31 and 108. If they were bad you would have trifecta lights I'm sure. If pump wasn't turning on I would expect you get a code. I don't know why you can't activate it with INPA. It is also known as the precharge pump.
Have you looked for DSC fault codes with INPA?
The two lines for the pump go the MC and MC reservoir. Not sure which is which but you should be able to sort that out just by following them back. My guess would be the line from the reservoir is into the pump and return is to the MC.
 

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Discussion Starter #76
I checked for any codes with INPA, none were found.



Today I took a look at the DSC Compressor.


First I cracked open each hard line fitting at the compressor and say brake fluid come out. Not surprise as there is a lot of brake line up above with/should have fluid within them.



Next I pulled the connector apart (near the compressor, what crappy plastic where the mounting tab broke!) and check for continuity through the compressor its self, and I did get a buzz from the meter. Next with INPA up and running and meter connected to power input to the compressor, I activated the compressor and got voltage showing. I reconnected the cable and activated the pre-charge pump (compressor) and I could clearly hear it running.


I will check with my neighbor to see when he could be my assistant (bleed screw turner) and bleed the whole system.


I will report back...
 

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Discussion Starter #77
Yesterday and today I had my neighbor give a hand with my brakes. We used ISTA+, latest version, to do the DSC venting. Ran the program twice but did not see/feel any change.

I also tried cracking each hard line coming off the Master Cylinder one at a time while the Power Bleeder was hooked up and my helper had pressure on the MC. I Did not see or hear any air escape, only some fluid weep before re-tightening the fitting.

Today while doing another ISTA+ purge, my helper spotted something odd after he closed the bleed nipple on the caliper. There were a large number of air bubbles coming out of the nipple hole that after a while stopped. With the nipple closed, where could the bubbles be coming from. The bubbles were definitely coming out the hole. I tried to capture a pix, but could not time it right. Because of the curve of the tube from the nipple, there was a couple of inches of brake fluid hanging there. I pressed very hard on the brake pedal to see if the fluid would move or more air come out. Did nothing, just sat there.

I will see about purchasing new nipples, clean the seats, etc... But I don't see the problem. There are no fluid leaks anywhere in the system.

This seems like the Oak Island mystery... more questions than answers!
 

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Was this done during the lunar eclipse?

I guess I would replace that nipple and rebleed. Have you checked all the soft lines for cracks/leaks?
 

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Yesterday and today I had my neighbor give a hand with my brakes. We used ISTA+, latest version, to do the DSC venting. Ran the program twice but did not see/feel any change.

I also tried cracking each hard line coming off the Master Cylinder one at a time while the Power Bleeder was hooked up and my helper had pressure on the MC. I Did not see or hear any air escape, only some fluid weep before re-tightening the fitting.

Today while doing another ISTA+ purge, my helper spotted something odd after he closed the bleed nipple on the caliper. There were a large number of air bubbles coming out of the nipple hole that after a while stopped. With the nipple closed, where could the bubbles be coming from. The bubbles were definitely coming out the hole. I tried to capture a pix, but could not time it right. Because of the curve of the tube from the nipple, there was a couple of inches of brake fluid hanging there. I pressed very hard on the brake pedal to see if the fluid would move or more air come out. Did nothing, just sat there.

I will see about purchasing new nipples, clean the seats, etc... But I don't see the problem. There are no fluid leaks anywhere in the system.

This seems like the Oak Island mystery... more questions than answers!
Mine do that, too. The X5 and the M5. I mean air bubbles form in the bleed line. I never really thought they were coming from the nipple, though, so maybe it's different.
Was this done during the lunar eclipse?

I guess I would replace that nipple and rebleed. Have you checked all the soft lines for cracks/leaks?
The super red wolf blood eclipse?!?
 

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The super red wolf blood eclipse?!?
I think OP will be howling at the moon if he doesn't solve this soon lol.

OP, with all the bleeding you have done and still seeing air bubbles, it sounds like you have a leak somewhere and air is getting pulled in when the brake pedal comes back up. I think I might replace all the bleed nipples and rebleed looking for bubbles again with a helper. Also check all the soft lines for cracks, possibly replace them as well.
 
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