Home Forums Articles How To's FAQ Register
Go Back   Xoutpost.com > BMW SAV Forums > X5 (E53) Forum
Arnott
User Name
Password
Member List Premier Membership Search Today's Posts Mark Forums Read

Xoutpost server transfer and maintenance is occurring....
Xoutpost is currently undergoing a planned server migration.... stay tuned for new developments.... sincerely, the management


Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 01-25-2018, 08:21 AM
Member
 
Join Date: Jun 2017
Location: Australia
Posts: 88
FourPointEight-is is on a distinguished road
Brake pedal hard

I seem to have lost about 80% of my power brake assist in my E53 4.8is. The car will still stop but I have to REALLY stand on the pedal to get any braking at all, it isn't effortless like it used to be.

If I brake gently (like coming up to a stop sign or lights) the pedal still feels somewhat "Normal" for the first 20% or so of its travel, but then suddenly the pedal becomes very hard - like I'm trying to compress wood. The brakes still work but require considerable effort to apply.

If I brake hard (like an emergency stop), the pedal goes down "normally" but then it suddenly firms up and kicks back against my foot at which point it feels like I'm trying to compress wood. Again, applying considerable effort, I can stop the car.

When stopped, I am having to apply considerable force to the pedal to keep the car stopped. I also feel a slight pulsating coming form the pedal as well (but its barely perceptible).

Does this sound like a brake booster issue? From the reading I've done there are recalls out for brake booster/vacuum line/check valve on the E70 X5s which share the braking system (parts and all) with the E53, but apparently E53 4.8is are not eligible?

Follow up question - if I need to replace the booster, is it worth also replacing the master cylinder or am I safe to reuse it? Is it possible to recondition the brake booster or is it a "throw away, get new" type part?

Lastly, if I replace the break booster and/or the master cylinder, I guess I need to bleed the whole system. Will ISTA be able to do this for me? If not which software do I need to do this?

Last edited by FourPointEight-is; 01-25-2018 at 08:29 AM.
Reply With Quote

Sponsored Links

  #2  
Old 01-25-2018, 09:02 AM
upallnight's Avatar
Member
 
Join Date: Aug 2012
Location: Cook County
Posts: 6,145
upallnight is on a distinguished road
Check the vacuum hose for a leak. No vacuum means no Power Brake.
__________________
2006 Infiniti G35
2001 BMW 3.0I E53 X5 Build date 08/2000
Lotus Europa 1970 Destroyed by fire
Lotus Europa 1970 S2 Renault Powered
Lotus Type 52 1970 Twincam Webers Powered
PORSCHE 911 Targa 1982 The Garage Queen
Audi Avant donated to Kars for Kids
BMW 525IT Sold
Audi 4000CS Quattro Sold
Jensen Healey Lotus Powered Sold
Opel 1900 Sold
Triumph Spitfire 1971 Sold
Triumph Spitfire 1968 Sold
Plymouth "Cuda" 340 Six pack SOLD
Reply With Quote
  #3  
Old 03-23-2018, 12:21 AM
Member
 
Join Date: Jun 2017
Location: Australia
Posts: 88
FourPointEight-is is on a distinguished road
Exclamation

Hi Guys, I finally got some time to look at this. The brake fluid is clean and not filthy plus the level is good indicating it was flushed in the recent past.

Unfortunately it appears that there is definitely some "foreign contaminants" inside the brake booster - video below. Also, there is some sludge build-up inside the vacuum hose as well - photo below. This must've been caused by a failed check valve.

Here is a look inside the brake booster with my snake cam: https://streamable.com/qunk0



To rectify this, I plan to change the following parts:
- Brake Booster
- The vac line from the vac pump @ front of engine -> booster

Questions:
- What is the best "pressure bleeder" to buy?
- Do I have to replace the master cylinder? It adds quite the cost to the project.
- I'm tight on funds right now, is it worth grabbing a booster from a wrecked X5 (after verifying that it is oil free of course) and just replacing the vac line or am I asking for trouble doing that?
Reply With Quote
  #4  
Old 03-23-2018, 03:15 PM
Member
 
Join Date: Feb 2018
Location: Georgia
Posts: 45
ID4.8 is on a distinguished road
Funny I see this now, I noticed this on mine just a few days ago. Do you hear a whooshing noise as you hold your foot on the pedal? I have the exact same symptoms as you and didn't even think about a vacuum line being an issue. Now that I have that in my head it would make sense based on the noise I'm getting as I hold my foot on the pedal.
Reply With Quote
  #5  
Old 03-23-2018, 03:40 PM
upallnight's Avatar
Member
 
Join Date: Aug 2012
Location: Cook County
Posts: 6,145
upallnight is on a distinguished road
Wow, that snake cam is like watching a colonoscopy on a BMW.
__________________
2006 Infiniti G35
2001 BMW 3.0I E53 X5 Build date 08/2000
Lotus Europa 1970 Destroyed by fire
Lotus Europa 1970 S2 Renault Powered
Lotus Type 52 1970 Twincam Webers Powered
PORSCHE 911 Targa 1982 The Garage Queen
Audi Avant donated to Kars for Kids
BMW 525IT Sold
Audi 4000CS Quattro Sold
Jensen Healey Lotus Powered Sold
Opel 1900 Sold
Triumph Spitfire 1971 Sold
Triumph Spitfire 1968 Sold
Plymouth "Cuda" 340 Six pack SOLD
Reply With Quote
  #6  
Old 03-23-2018, 05:53 PM
Member
 
Join Date: Jun 2017
Location: Australia
Posts: 88
FourPointEight-is is on a distinguished road
I don’t have any vacuum leaks from what I can see. My vacuum pump is dripping some oil but this is a 15 year old car so not exactly out of the ordinary. I think the sludge inside of the pipe and the orange mist and debris inside the booster body indicates the seals on the oil pump went bad causing oil to go through, contaminating the lines and the booster with oil. The oil will cause the seals to swell and fail.

My initial symptom was the brakes felt terrible but still stopped the car. I didn’t read too much into it because they still worked fairly well. Then eventually the pedal started getting hard to press. Usually hard pedal equals vacuum or Booster problems.

Some X5s have actually been recalled but many (who apparently used the same parts) haven’t.

BMW, in notifying the National Highway Traffic Safety Administration, said only vehicles equipped with V8 engines are affected. BMW, in its NHTSA filing, said the "brake vacuum pump may leak a small amount of lubricating oil into the vacuum hose (which) could result in contamination of the brake booster."Feb 15, 2013

http://www.autonews.com/article/2013...oreUserAgent=1

Quite an expensive repair. The booster itself is around 250-300 (TRW). If you want to replace the master cylinder (you might as well when you’ve got everything apart) is another 150. The vacuum line itself will be another $50-100 or so. Plus 3 hours of your time to replace it, then god knows how long to bleed the system properly (it requires at least a pressure bleeder AND INPA for bleeding the ABS pump)
Reply With Quote
  #7  
Old 03-24-2018, 06:14 PM
Member
 
Join Date: Feb 2018
Location: Georgia
Posts: 45
ID4.8 is on a distinguished road
I'm really wondering if I'm having a vacuum pump related issue then. My pedal goes soft after a hard stop or if I sit in stop and go traffic it gradually loses pressure then builds back up, then goes soft again after more use.
Reply With Quote
  #8  
Old 03-24-2018, 06:32 PM
Member
 
Join Date: Jun 2017
Location: Australia
Posts: 88
FourPointEight-is is on a distinguished road
Unhook the vacuum line from that booster and have a look. Only takes a minute. It should be clean. Any gunk or orange colour inside like mine above is bad news.
Reply With Quote
  #9  
Old 03-24-2018, 07:24 PM
Member
 
Join Date: Feb 2018
Location: Georgia
Posts: 45
ID4.8 is on a distinguished road
Does it just pop right off?
Reply With Quote
  #10  
Old 03-24-2018, 07:44 PM
Member
 
Join Date: Jun 2017
Location: Australia
Posts: 88
FourPointEight-is is on a distinguished road
Yes. I used a short rachet handle wrapped in a rag so as not to damage anything.

It helps if you remove the trim immediately above the wiper but I’m sure it can be gotten to without doing that.

Just found this article: https://www.productsafety.gov.au/sys...%20Booster.pdf

E53 not eligible by the looks of things despite using the smamw engine, same lines and same booster/cylinder etc. Nothing like giving the middle finger to your loyal customers
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On





All times are GMT -4. The time now is 01:42 PM.
vBulletin, Copyright 2018, Jelsoft Enterprises Ltd. SEO by vBSEO 3.6.0
2017 Xoutpost.com. All rights reserved. Xoutpost.com is a private enthusiast site not associated with BMW AG.
The BMW name, marks, M stripe logo, and Roundel logo as well as X3, X5 and X6 designations used in the pages of this Web Site are the property of BMW AG.
This web site is not sponsored or affiliated in any way with BMW AG or any of its subsidiaries.