CIS Valve
 

Hi Guys,

I just had a new pop off valve installed in my 1980 SC. Recently I tried to start it and had no luck. when messing around in the engine bay I happened to remove the air box cover and noticed that the valve which normally sits at the lid of the pop off valve had come out of its normal housing. When I put it back the car started with no problems at all.

It happened again tonight but not to the same degree as above. tried starting. no luck. thought I would check the pop off valve again. It had moved a couple of mills from where it normally sits. pushed it back in place and car starts!

My questions are two fold.

1. is this a common problem I need to get used to.
2. are there any fixes?

would appreciate any advice you guru's can offer to a newbie!:)

Pop valve........
 

Find a good epoxy glue like JB Weld or similar. Your problem is having good adhesion between the pop off valve and the air box. However, if you are experiencing back fires with a properly installed pop off valve, consider checking for unmetered air source in your system. I have installed my pop valve ('78 SC) in the early 90's and haven't done anything to it till now (knock on wood). Many have experienced valve separation like you had and I don't expect mine to last forever too. Keep us posted.

Tony

You could use acetone to clean the parts before mating.

Use the 24 hour JB Weld.

Do you mean, the top portion of the Pop-Off valve is coming off of its hinge or the whole assembly is popping off?

Thanks guys. Will try it out.

Don - no, not the entire assembly. Just the rubber(?) o ring which seals the o-ring. Will try to take a pic for you.

Cheers - and have a great Christmas!

Put a little Dow Corning 111 o-ring grease or similar on the o-ring, it may help seal it up.

+1 Dennis.

You have a Merry christmas as well.

hi guys,

Was hoping for the best because the o ring had not jumped out of its housing for a bit but it happened again this morning.

This time however, I was prepared. I could not find any JB weld (bob) or Dow Corning 111 (dennis) so I put some "selleys multi grip" on and glued the o-ring into place.

I cant tell whether it is epoxy based. the packaging says that it contains acetone though. and it is also for most plastics and rubber.

The back of it does say that it will not join polythylene or polypropolene which may be a problem?

In any case, I've glued the o ring in and am hoping for the best!

If I've made a grievous error please tell me. Also, if there is no chance the glue is going to stick let me know also. better to know that not know!

hope you are all enjoying the holiday season. thank you for any advice you can offer.

If this fails to work, I'll need advice on how to get the glue out!!

cheers
j

I don't thnk that will solve your problem of the O-ring not sealing to the lid.
O-rings dry out over repeated heat cycles and shrink. The dow corning O-ring lubricant(s) 111 or 55 actually penetrates the rubber and allows it to swell up and seal.
I sent a new O-ring I had to a pelican a while ago when he was having the same problem you are.
Should be simple to find one at a hydraulic shop along with some o-ring lube.
Just pop yours out and take it with you.
Post #6 has the dimensions you are looking for in this thread:
http://forums.pelicanparts.com/porsche-911-technical-forum/719223-bad-pop-off-valve-gaskets.html

Hi porsche guru's. Sorry for the delay in getting back and closing this off. the good news is that I've been driving the car for some time now and the glue I used seems to have fixed the problem!

If it comes off again, at least I have some alternative solutions!

thank you.