Need help with NON-RETURN VALVE in brake boster, Please......

[Akhil]

Hi Guys,

Today I was inspecting engine bay in my 92 525i (M50) and I heard soung of air being blown or sucked. I tried to pin point the where its coming from, then found out it was around NON-RETURN VALVE between intake mainfold and brake booster. I took NON-RETURN VALVE out and compaired it with # 17 in pic here http://www.realoem.com/bmw/showparts.do?model=HD63&mospid=47404&btnr=34_0285&hg=34&fg=25 . I was really surprized to see a tini hole in my NON-RETURN VALVE at the place where #17 in pic has a tube which I believe is to be connected to some where in vacum line, But I have no idea where? Mine was broken all the time and I didn't see any open or unconnected vacum ture around that area. Does anybody know where that line need to be connected or anybody with same year and model can do me a faver and look into his car and let me know where that line will connect? Another question I have is, since mine was broken, means no place to connect the vacume line until I replance that valve, Can I just close that hole with somting to avoid air being sucked from there and the other end of the line where this line connectes?

Thanks a lot in advance.
Regards,
Akhil

[winfred]

it's common for that nipple to get broken off, you can seal it with some rtv or epoxy just don't run the motor till it's cured or you will suck it inside of the valve, i don't think i've ever seen anything connected to that valve

[Akhil]

Thanks a lot winfred,

That makes me wonder, if nothing is connected to that nipple, then what difference it makes if it broken or not? Because either case it will leave a hole for unfiltered air to be sucked in, Right?


Regards,
Akhil

[winfred]

it starts off being capped so it's not leaking till the end gets snapped off, it's not so much the fact it's unfiltered air as it is unmetered air messing up the mixture

[Akhil]

Thanks a lot for your reply winfred,

So for now, until I replace that valve, if I just seal that hole with something, do you think I can drive it? Would it be any bad effect on engine?

Regards,
Akhil

[632 Regal]

youll be good to go, as winfred said seal it with some rtv or whatever.
Thanks a lot for your reply winfred,

So for now, until I replace that valve, if I just seal that hole with something, do you think I can drive it? Would it be any bad effect on engine?

Regards,
Akhil

[Akhil]

Thanks a lot guys for all your help. I found a little plastic thing in my junk box, I don't know what it it, but it has a flat head like rivit which fit on the hole just like a cap and I was able to seal it without using any adhesive. I tested it by blowing air from both side. It let me blow only towards intake side not toword booter side. which I believe is correct and no leak from the hole. And since that platic pthing has flat head I wouldn't have to worry about being sucked into the valve. Now I am gonna put it in my car and let see if that makes any differace in drivig conditions.

Once again Thanks a lot for all your helps.

Regards,
Akhil

[winfred]

that small of a leak won't really effect it while at speed but will mess with the idle