Our cars are getting on so, while I was doing the DISA and VANOS valve upgrades, I went over the the external hoses. What I found may well be typical of cars from that time. The first picture shows the vacuum brake booster hose....looks reasonable...until you turn it 90 degrees and then not so good. The hose was almost entirely collapsed, leading to very little vacuum being induced. Fortunately there was still enough to operate the brakes. Note: For whatever reason the photos have loaded opposite to their number, so look at the second picture first. :headbang:
Word of warning.....
- Thread starter rdgreen
- Start date
ph001 said:
Unfortunately you need a flexible hose between the engine take off and the brake booster as the engine isn't solidly mounted to the chassis and the booster is. Obviously the original has lasted for some time, but nothing lasts forever......brake lines next for a check.
Interesting that BMW issued a TIS technical bulletin to dealers about this apparently common condition of squished vacuum hoses, quote
"A deformed vacuum hose still has sufficient reserves for the brakes to function correctly, in no instance is the braking effect jeopardised by the deformation. In case of customer complaint, do not replace the vacuum hose!
Technically they are almost certainly right, but it makes them look like a cowboy shower of s4it!
"A deformed vacuum hose still has sufficient reserves for the brakes to function correctly, in no instance is the braking effect jeopardised by the deformation. In case of customer complaint, do not replace the vacuum hose!
Technically they are almost certainly right, but it makes them look like a cowboy shower of s4it!
Ewazix said:Interesting that BMW issued a TIS technical bulletin to dealers about this apparently common condition of squished vacuum hoses, quote
"A deformed vacuum hose still has sufficient reserves for the brakes to function correctly, in no instance is the braking effect jeopardised by the deformation. In case of customer complaint, do not replace the vacuum hose!
Technically they are almost certainly right, but it makes them look like a cowboy shower of s4it!
Hose.PNG
Think my car has this. I noticed feeling in the brakes was lacking, and then I remembered road side assistance did remark something about a deformed hose under the bonnet (when they were checking my broken alternator). It just looks like the one in the picture.
Think its wise to replace ASAP, did I see correctly the partno is 34336763992?
When changing, do I need to order other parts as well?
Many thanks in advance!
Think its wise to replace ASAP, did I see correctly the partno is 34336763992?
When changing, do I need to order other parts as well?
Many thanks in advance!
mpc007 said:
To be honest I just went to the local auto spares outlet and bought a vacuum hose of the correct diameter that followed the contour almost exactly. Part number is ZHB12EFV and it cost me less than $20 (about 12 pounds) all up with a couple of hose clamps to replace the BMW ones that you will need to cut off carefully. You could buy the genuine BMW ones....but you would probably need to mortgage the house first.
rdgreen said:mpc007 said:
To be honest I just went to the local auto spares outlet and bought a vacuum hose of the correct diameter that followed the contour almost exactly. Part number is ZHB12EFV and it cost me less than $20 (about 12 pounds) all up with a couple of hose clamps to replace the BMW ones that you will need to cut off carefully. You could buy the genuine BMW ones....but you would probably need to mortgage the house first.
What fou you mean by cutting them off? Is there pressure on the hose when removing it? :roll:
mpc007 said:rdgreen said:mpc007 said:
To be honest I just went to the local auto spares outlet and bought a vacuum hose of the correct diameter that followed the contour almost exactly. Part number is ZHB12EFV and it cost me less than $20 (about 12 pounds) all up with a couple of hose clamps to replace the BMW ones that you will need to cut off carefully. You could buy the genuine BMW ones....but you would probably need to mortgage the house first.
What fou you mean by cutting them off? Is there pressure on the hose when removing it? :roll:
You need to cut off the hose clamps holding the hose on because BMW use clamps that are single use only. If you have pressure on a vacuum line you have other issues to worry about......
One would assume BMW have tested the hose to breaking point otherwise they would recommend replacing,,,,,,, hopefully,,,,,, ???Ewazix said:Interesting that BMW issued a TIS technical bulletin to dealers about this apparently common condition of squished vacuum hoses, quote
"A deformed vacuum hose still has sufficient reserves for the brakes to function correctly, in no instance is the braking effect jeopardised by the deformation. In case of customer complaint, do not replace the vacuum hose!
Technically they are almost certainly right, but it makes them look like a cowboy shower of s4it!
Hose.PNG
Yeah, they're not that expensive. I could order one for ~20 EUR from a dealer so did that. Hope to see it arrive soon, now having seen this topic 
Guess maybe best bet to remove the clamps carefully is just to saw them off with a small iron handsaw?
Edit: Just had the part delivered so decided to have a go at it. Had an argument with the OEM single-use hose clamps, until I found out that indeed the easiest way is to pry up the end where it falls over the little ridges. It then releases and you can easily dispose them with pliers. The one way return valve at the end of the brake booster came with the hose when pulling it loose, but it did look OK so switched it over to the new hose. Then reinstall the hose, making use of some easier to use clamps (in my opinion). Did a quick test drive, brakes seemed a bit better than earlier (felt a bit numb) but have to drive longer to make up the conclusion. For anyone who noticed; my DISA valve is currently unplugged because it rattles. Its on my list to look into it, but in order to prevent it falling apart while working I decided to shut it down for now.
Guess maybe best bet to remove the clamps carefully is just to saw them off with a small iron handsaw?Edit: Just had the part delivered so decided to have a go at it. Had an argument with the OEM single-use hose clamps, until I found out that indeed the easiest way is to pry up the end where it falls over the little ridges. It then releases and you can easily dispose them with pliers. The one way return valve at the end of the brake booster came with the hose when pulling it loose, but it did look OK so switched it over to the new hose. Then reinstall the hose, making use of some easier to use clamps (in my opinion). Did a quick test drive, brakes seemed a bit better than earlier (felt a bit numb) but have to drive longer to make up the conclusion. For anyone who noticed; my DISA valve is currently unplugged because it rattles. Its on my list to look into it, but in order to prevent it falling apart while working I decided to shut it down for now.
I bought the BMW hose for $20 from ECS Tuning.rdgreen said:mpc007 said:
To be honest I just went to the local auto spares outlet and bought a vacuum hose of the correct diameter that followed the contour almost exactly. Part number is ZHB12EFV and it cost me less than $20 (about 12 pounds) all up with a couple of hose clamps to replace the BMW ones that you will need to cut off carefully. You could buy the genuine BMW ones....but you would probably need to mortgage the house first.
