1996 850 GLT Need to find vacuum leak >> found

[erikv11]

Yep, the red arrow is correct.

[mecheng]

Thanks! I'd be interested in hearing how anyone was able to replace the elbow. In is reinforced with steel so I'm not sure how anyone was able to apply enough force in that area

[erikv11]

I think you will find that most people just go with a separate line, the elbow is PITA. Or replace the elbow when doing the PCV job, the manifold is unmounted from the engine at that time.

[mecheng]

The previous owner gave me the service records for the S70. I found the invoice for the Volvo dealer replacing this elbow, they did it with 1hr of labour charge. Not sure how they did it in 1hr, maybe they removed the manifold.

Anyways, I hope this clears up the repair for the future owners who get a P0172 code. Thanks all

[joe_pinehill]

I tackled this problem last night, I had a bad feeling it would be a bitch and I was right; even though it looks easy.

First thing I did was remove the upper radiator hose to get access to the elbow. I was able to remove the elbow with a angled needle nose pliers on the manifold side. The other end of the elbow was stuck to the hose. I hosed it down with Liquid Wrench and after about 20 mins of trying to pull it off it finally came apart slowly in pieces because it was so brittle.

I tried installing the new elbow; well there was a lot of swear words. I felt like punching the sweedish engineer who designed this hose system. Getting the elbow onto the intake manifold was a bit tricky but I was able to do it. Getting the other end of the elbow onto the hose is virtually impossible because it is a tight fit and you need to find a way to hold the hose and push against it. Good luck, there is no room. Maybe with two people, but I'm doubtful.

So I caved and ran a new line to the PTC valve. I'm not 100% sure I connected it to the right port but I believe I followed the line correctly (not easy to do because it is hidden).

Does this appear correct, see Red arrow.

Was it hard to route the hose to the flame trap nipple? Seems very tight with the throttle body linkage.

I dont have any signs of needing a pcv service, but i do need to replace this line.

[erikv11]

mecheng has a turbo, so the line doesn't go to the flame trap on his car but to the PTC - somewhere else.

On an NA when routing to the flame trap nipple: yes it is tight in there, you will likely need to pull a few things apart first. I would probably take out the air cleaner box, that just takes a couple minutes, then go from there. Also the cover on the throttle body if it is still there, the distributor cap maybe.

Do be careful with the nipple at the flame trap housing, it can be fragile. If you break it off, then you need to get a new plastic housing.

EDIT: Some of the pics in this thread may be useful to you, https://www.matthewsvolvosite.com/forums ... 1&start=35.

[joe_pinehill]

I was more wondering about space to route from the nipple then out from under the TB linkage, the line would be going opposite the OEM line running under the intake, and then the run the right side of the intake manifold (RH wrt to the driver) seems the easy part. i'll give it a try tomorrow.

[erikv11]

I usually get the new vac line (5/16 rubber works well) attached at the manifold first, then route it over to the flame trap however you want (I usually go at least under the fuel rail cover, much like the OEM routing), then cut it to length and attach it at the flame trap nipple. It's not a bad job. And usually I just leave the remnants of the old line in there, unless doing a full PCV job.

[dosbricks]

On both our NAs I got rid of the nuisance of that elbow on the left side of the manifold by substituting a hard plastic vacuum elbow with a different diameter fitting on each end. Larger end matched to a short piece of fuel line to connect it to the manifold. Smaller end attached to 1/8" fuel line under the manifold to the flame trap. All connections secured with band clamps.

Fuel line far outlasts rubber vacuum hose where it is exposed to oily vapors like in this PCV application, and the plastic 90 degree vacuum elbow will outlast a half-dozen of those rubber OE elbows. Not glamorous, but who sees it?

mecheng, I hear you when you say it's virtually impossible to get the OE elbow off the hard plastic line and then grip the latter to get the new one on. This whole PCV system was, in my book, not a stellar piece of mechanical engineering.

[JimBee]

On both our NAs I got rid of the nuisance of that elbow on the left side of the manifold by substituting a hard plastic vacuum elbow with a different diameter fitting on each end.

dosbricks: please include a link or specific source and make of the plastic elbow you used.
Thanks,
Jim