Need some help identifying a vacuum hose on a '91 318is...

[RossfromAZ]

Hi all,

I would like to replace the brake booster vacuum hose; however, I can't seem to figure out what part to order. On realoem, the particular hose assembly on my car is not depicted, and the ones that *are* seem to be greyed-out for whatever reason (https://www.realoem.com/bmw/enUS/sho...diagId=34_0703) — quite confusing.

Attached below is a picture of the hose assembly in question — thanks in advance:

[DEV0 E30]

It's hard to tell from the angle, on your "check valve / non-return valve" how many directions does it go in? Can you spot a part number on any of the pieces?

EDIT: Since some items are no longer available (NLA) --- I should have just given you this link --- Mike's detailed build/log is full of great information like this.

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Another Realoem-like resource, it's in another language but you can cross check part numbers: link

Realoem from a euro car part numbers: link

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I believe you'll be able to get everything from FCP (I simply like their return policy).

Various check/non return valves from FCP: link

Brake Booster search yielded these: link

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Looking at your username, welcome, I'm also in Arizona. There are a few of us still active on here that are local to you most likely.

[RossfromAZ]

It's hard to tell from the angle, on your "check valve / non-return valve" how many directions does it go in? Can you spot a part number on any of the pieces?

Realoem from a euro car part numbers, showing one that goes three ways: link

This thread may also help: link

======

I believe you'll be able to get everything from FCP (I simply like their return policy).

FCP: Two way non-return valve: link

Various check/non return valves from FCP: link

Brake Booster search yielded these: link

Thanks for replying,

I should clarify, I *do* have what I believe to be the correct check valve (it is one direction, btw) already in my shopping cart; however, the hose leading to the engine is confusing me:

• What, if any, function does this plastic piece perform (circled in green)?
• If the aforementioned part *is* necessary, what is the part number (I wonder if this may not be the correct part to begin with)?
• Can this assembly be replaced with just a simple vacuum hose? (circled in red)

Edited image is attached below, thanks again:

[DEV0 E30]

Hey Ross --- I edited my post --- I'd follow what Mike did:

EDIT: Since some items are no longer available (NLA) --- I should have just given you this link --- Mike's detailed build/log is full of great information like this.

===

• That's the check valve, it basically ensures air only goes in one direction to give vacuum.
• That part appears to be NLA --- I'd use the part number Mike used in his thread.
• Yes --- you can use any vacuum line that works/fits there, I wouldn't spend the money personally on specific vacuum line that is cut/formed to that space if BMW even still sells it.

[RossfromAZ]

Hey Ross --- I edited my post --- I'd follow what Mike did:

EDIT: Since some items are no longer available (NLA) --- I should have just given you this link --- Mike's detailed build/log is full of great information like this.

===

• That's the check valve, it basically ensures air only goes in one direction to give vacuum.
• That part appears to be NLA --- I'd use the part number Mike used in his thread.
• Yes --- you can use any vacuum line that works/fits there, I wouldn't spend the money personally on specific vacuum line that is cut/formed to that space if BMW even still sells it.

Thank you so much, DEVO — answered all my questions!

Embarrassingly, I was conflating the check valve with the t-elbow that connects to the booster itself; of course, it is the mystery plastic piece in question that is the check valve, duh, my inability to locate the part number (due to NLA status as stated in your link) added to my confusion as to its function.

I will go with the solution found in Mike's forum post.

Best regards,
Ross

[DEV0 E30]

No problemo.

I see you're in Tucson - if you find yourself in Phoenix, feel free to post or follow along to this thread:

https://www.r3vlimited.com/board/for...rounding-areas