1996 850 confusion about vacuum hoses

marcusmcd · Post by **marcusmcd** » 05 Apr 2014, 18:25

When I took this car apart last year I SHOULD have labeled things before disconnecting. A lot of these hoses are rotted and were falling apart. But at this point I'm not sure what goes where and the provided diagram is not very clear, especially since I don't know all the terminology. I have three pictures:

The first shows three nipples near the rear of the engine, plus one new hose draped across the middle, and one old hose snaking up from down below toward the camera. I assume the new hose, which runs to the intake manifold, connects to one of these, but doesn't seem to fit any of them. What connects to the other two, and where does the existing old hose connect?

This shows a larger-diameter hose coming up just behind the radiator, from below the air intake housing, and it appears to run back under the car. I assume it somehow connects to one of the two valves shown in the picture, but the hose doesn't seem to bend in a way that would fit.

This shows one nipple on the intake manifold below the vacuum tree. It also shows two hoses connected, but I am not sure they are placed properly. The diagram shows that one hose should lead from this point to the check valve, which I think is in the bottom right hand corner of the picture, but the nipples are of different diameters.
Also, the vacuum diagram identifies purge, PTC nipple, Bypass valve, pressure gauge, and waste gate, but I cannot identify them on the engine itself. Pretty sure I know where the TCV is since it is the only thing with three nipples.

Any light you can shed on this would be helpful. Thanks!!, Mark

Post by **rspi** » 05 Apr 2014, 19:39

This might help:

The first picture shows the PTC valve missing it's small line that wraps around the motor to the intake's passenger side, along with the larger hose that goes to the oil trap box.

The last picture with the vac off of that valve on the fan goes into the front of the intake below the IAC, you can see the port open.

Let me look at the middle pic again.

Post by **rspi** » 05 Apr 2014, 19:41

That larger loose hose in the middle picture looks like the brake booster hose that travels under the air box. It connects to the brass elbow on the front of the intake under the IAC.

Post by **polskamafia mjl** » 05 Apr 2014, 19:49

I think I can help with picture # 1

: IMG_20140405_182624.jpg (113.83 KiB) Viewed 5373 times

# 1 I believe is for the boost gauge in the instrument cluster

# 2 Is hose 19 in this picture and runs to the TCV

: TCV to Turbo.jpg (137.98 KiB) Viewed 5373 times

# 3 Is part of the PCV system. You should have a hose run from # 3 all the way to the passenger side of the intake manifold. The arrow is pointing to where that hose should connect to.

Post by **rspi** » 05 Apr 2014, 20:11

Nice, where does that BLUE line go?

On the #3 in the pic, that hose is actually lying across the #2 valve. It comes TO LONG in the PCV kit, also, the end is usually to large to fit on the PTC fitting. I usually pull the end off, trim about 1 inch off of the hard plastic tube, then put a silicone tube on the end of it to connect it to the PTC nipple.

Post by **rspi** » 05 Apr 2014, 20:23

Some more pics...

: Vacuum hoses on Volvo 850; hoses.jpg (155.58 KiB) Viewed 5372 times

: Volvo 850 manifold vacuum ports; mani.jpg (71.2 KiB) Viewed 5372 times

Post by **polskamafia mjl** » 05 Apr 2014, 21:24

Blue hose should run up to the fresh air pipe that goes from the air box down to the turbo.

Post by **rspi** » 05 Apr 2014, 22:07

Thanks. That is what I thought

Post by **Ben850** » 07 Apr 2014, 00:24

I was genuinely confused last year. I had no experience with a Turbo 850.
I am better now for learning some of the intricacies from this site.
This is the place.

My 1996 Maintenance is here.
It applies to a wagon or a sedan.

https://www.matthewsvolvosite.com/forums ... 35&t=56550
Good luck.

marcusmcd · Post by **marcusmcd** » 10 Apr 2014, 21:27

rspi: Please remember I'm a novice: What does IAC stand for? I found the brass coupling where the hose you labeled #4 should connect, but it pretty much disintegrated in my hand while trying to connect it. Meanwhile, is there a hose that is supposed to go between #5 and the intake manifold? I might be missing that.

Polskamafia: Thanks for the diagram. You state that the blue hose runs to the fresh air pipe. I am not finding a nipple to connect it to on that pipe. Can you tell me where it should be and/or provide a photo? Same for the red hose; where does it connect? I don't see any likely connectors back there. And where does the bracket #23 in the diagram go?

Ben850: If you have any more photos of where hoses and such should go, please share.

Thanks, all of you. I hope to get this running before my daughter (the intended driver) gets home from college.