I need confirmation that my symptoms are brake bomb related.
1. I get a recurring noise from the engine bay near the pentosin reservoir every 7 seconds when stepping on brake. I checked to make sure no air in the system by checking for bubbles in the reservoir when pumping the brake.
2. Brake is soft but no issues with stopping.
3. I know I am missing one of the rubber seals that sandwich the filter (the top one)...not sure if that could cause the repetitive sounds.
4. Groaning when turning steering wheel.
Thanks in advance for ur advice.
Sent from my SM-G950U using Tapatalk
When you slam on the brakes and it stops today, The Accumulator is fine! It will be stiff hard stopping with a delay when it go's south from my experience, If the pentosin level and filter is ok, There is a post on adding a small cut in the top of the reservoir to relieve some air pressure and the winding noise has left in several cases.
Too low pentosin level?!
My brakes were soft but braked like you described although the ABS never activated. The reason was I had never ever changed brake fluid. Not too much air in the system but water in the fluid. After changing ABS worked and brakes were stiff/hard and did their job much better.
Last edited by peake; 12-11-2017 at 11:20 PM.
Could the noise be the pre-charge pump running? Removing the relay would test this (and probably be rather dangerous) - K94:
http://www.meeknet.co.uk/e31/Timms_B...lay_Finder.htm
Last edited by Timm; 12-13-2017 at 03:25 PM.
Timm..2007 E64 650i Individual Sport..1999 E31 840ci Individual Sport..ex owner of 2000 E38 740..1999 E38 740i V8 M62..1998 E38 735i V8..1993 E32 730i V8..1988 E28 518i
My BMW Repair YouTube Channel
My Current 840ci Sport Individual
My Current 650ci Sport Individual
My E31 Repair and Information Website
My E38 Repair and Information Website
My E63/E64 Repair and Information Website
Chase - Heroes to a generation
If the booster 'bomb' is original, it is - at a minimum - 20 years old!! That rubber diaphragm does not last forever. Mercedes has used these accumulators for self leveling and to augment the hydraulic suspension in cars for quite a long time. Ten to fifteen years is considered a reasonable lifetime in that community. I always replaced mine at around 12-15 years on the Benzes.
I replaced this pressure accumulator on the e31 a few weeks ago. I've noticed improved braking and less hydraulic fluid/pump noise. Working slowly (on a lift), probably took about 2 hours for the job.
Gary
Last edited by Gary Knox; 12-12-2017 at 09:24 AM.
Gary Knox
'97 BMW 840 Ci
'03 MB SL55 AMG
'07 Mini Cooper S hatchback
'09 Aston Martin DB9 Volante
'13 Audi A8
'90 MB 560 SEC and '94 Porsche 928 GTS recently departed but long enjoyed
50 or so others over the past 70 years of driving
No, I meant K94.....
Timm..2007 E64 650i Individual Sport..1999 E31 840ci Individual Sport..ex owner of 2000 E38 740..1999 E38 740i V8 M62..1998 E38 735i V8..1993 E32 730i V8..1988 E28 518i
My BMW Repair YouTube Channel
My Current 840ci Sport Individual
My Current 650ci Sport Individual
My E31 Repair and Information Website
My E38 Repair and Information Website
My E63/E64 Repair and Information Website
Chase - Heroes to a generation
The K94 is present in the 840 but is it also present the the older 850?
If you have slip control 5 then you have K94 - otherwise the relay is part of the hydraulic unit Y1
Timm..2007 E64 650i Individual Sport..1999 E31 840ci Individual Sport..ex owner of 2000 E38 740..1999 E38 740i V8 M62..1998 E38 735i V8..1993 E32 730i V8..1988 E28 518i
My BMW Repair YouTube Channel
My Current 840ci Sport Individual
My Current 650ci Sport Individual
My E31 Repair and Information Website
My E38 Repair and Information Website
My E63/E64 Repair and Information Website
Chase - Heroes to a generation
Bookmarks