Rear Cam Seal "how To"

[JBVolvo]

Please Note: This is being preformed on a 96 Non Turbo 850. A turbo may have tubing that will need to be removed to gain access.

There are 4 Cam Seals. 2 Front (same 2 seals for the front), 2 Rear (same 2 seals for the rear)

In this how to, I'm replacing one of the 2 rear seals, underneath the cam position sensor. The other REAR is located behind the cap and rotor.

It can be VERY DIFFICULT to diagnose this as the cause of the leak due to the way it routes the drip around to the back of the engine. Some have a weep hole as well, although I didnt see one on mine. Even after I'd removed the cover the first time, there were only trace amounts of oil inside the cover. It'll only leak while you are driving due to the fact that it's the only time it sees pressure. Mine dripped down through the bottom of the cover, and the lower mounting bolt threads were wet. The oil dripped down onto the drivers side CV joint, and collected underneath at the gasket between the engine and transmission (where I noticed it for the first time) leading me to fear the worst of a RMS leak. Instead I was psyched to find it was an easy to replace $3 cam seal which I purchased via FCP, which was replaced shortly after with a Volvo seal.

A few CRUCIAL POINTS before you start:

1. Although FCP sells an "OEM" seal, it's not a Volvo seal, and there are some differences to its design. The Volvo seal appears to be more of a thoroughly designed seal, and perhaps more rugged. Take it for what its worth. I prefer the Volvo seal.

2. It is IMPERATIVE to make sure you seat the seal FLUSH with the outside edge of the housing, and its IMPERATIVE that you seat it EVENLY with a large socket to tap it in, or something similar. THERE IS NO WAY TO REMOVE IT FOR A "RESEAT" if you fail to do it correctly. You end up compromising the seal on removal.

There is a VERY good chance it will leak if you miss either of these two points. If its recessed, it's likely it will leak.

Before I start, this is a pretty simple job even for your first time if you pay attention to the points above....to prove it, I went to a HomeDepot parking lot during my 45min lunch break and had plenty of time to spare (even with taking pix for you bitches, gotta love camphones).

Location of cam position sensor (shown with a black cover in this photo):

Location of BOTH rear cam seals (this how to is only for the seal under the cam pos sensor):

Start by removing the two T40 torx mounting screws on the Cam Sensor Cover.

They sit at 1oclock, and 7oclock, and you may gently bend the bracket fastened at 1oclock to gain better angle:

Here's a shot with the cover off (old seal, trace amounts of oil even though it still leaked all the way to the undercarriage):

Once you've removed the cover, you'll have access to the 10mm bolt in the cam.

A 3"-6" extension will make it easier. Take note what position the scoop is in so you can put it back the same way:

After you've completely backed out the bolt, carefully remove the bolt with its washer, and scoop (for lack of a better word):

With these three parts out of the way, you'll have access to the seal. Either hook it gently from the inside being carefull not to damage the sealing surfaces, or you may start a screw within the seal and pull it out that way:

Here's a shot of the seal removed. Clean up the seal surface and inspect for damage:

The seal goes in with the concave side IN:

Use a little motor oil on your finger to lubricate the mating surface of the seal:

IMPORTANT: Use a large socket or something similar to tap the seal in evenly until its FLUSH WITH THE OUTER SURFACE or you WILL have leaks:

The "scoop" is keyed on the backside, so if you took note as mentioned of its GENERAL positioning beforehand, you should be fine. Otherwise, you're a dope and it's 180degrees off:

I'm not sure what exact torque is for this 10mm bolt, you'll have to look it up, but its not a heavy torque at all.

Once its all back together, start the car, take it for ride and look for any signs of leak.

[Oreo931]

Finally, you posted a worthy thread in the 1998 and prior section!

J/K man. Very nice write up. I didnt realize how easy this was!

[Ihatespeedbumps]

/

[JBVolvo]

I think the only thing missing from this DIY is when replacing the seal, you should take note of exactly where the old seal sits. The new seal should be installed in the same position. Otherwise, great write-up.

why is that? the seal is the same all the way around...there's no rotation position the seal itself sits.

I mentioned which side faces in towards the engine as well.

if you're speaking of the "scoop" position, I mentioned that

[Ihatespeedbumps]

why is that? the seal is the same all the way around...there's no rotation position the seal itself sits.

I mentioned which side faces in towards the engine as well.

if you're speaking of the "scoop" position, I mentioned that

[Mike_P]

Nice write-up JBV. I could not find torque values for the 10mm either, but you will find they are on fairly tight when you remove them.

If you do the intake rear seal at the same time, remove the distributor cap and rotor/shield first. You can remove the air box prior to this to create more room. Once cap/rotor is off the procedure is basically the same as the exhaust seal. Only difference is that the hardware at the end of the cam is the rotor mount plate. It is keyed (as is the plate on the exhaust cam)so as long as you seat the key on reinstall you are good, there's no special orientation to worry about.

Also note that JBVolvo has an N/A. If you have a turbo I think there's more piping running through that area that will potentially be in the way

[ozzimark]

nice. i have a mysterious leak that i need to track down. glad to know that if it's the rear cam seals, that's an easy job

for the turbos, the intercooler piping takes all of 2 minutes to take out :lol:

[Yellow95]

Can the seals be pushed in too far or do they seat against something.

Gary

[JBVolvo]

Can the seals be pushed in too far or do they seat against something.

Gary

No, you push it in as far as it'll go, and it stops against another edge inside.

Not sure what Ihatespeedbumps was referring to.

Also note that JBVolvo has an N/A. If you have a turbo I think there's more piping running through that area that will potentially be in the way

thanks, I updated the how to and added that to the beginning

[Mike_P]

Can the seals be pushed in too far or do they seat against something.

Gary

They will rest against the back side of the bore (you can see it in the pics). I struggled with this when I did mine and ended up seating them fully - I didn't want any oil to pool up behind the seal.

Edit - sorry JBVolvo, we must have posted at the same time....

[JBVolvo]

They will rest against the back side of the bore (you can see it in the pics). I struggled with this when I did mine and ended up seating them fully - I didn't want any oil to pool up behind the seal.

Edit - sorry JBVolvo, we must have posted at the same time....

its all good....is this worthy of the "How To" section? would've been nice to have ahead of time

[Ihatespeedbumps]

No, you push it in as far as it'll go, and it stops against another edge inside.

Not sure what Ihatespeedbumps was referring to.

I haven't done any in a while, I must have confused myself w/ something else. Didn't mean to sound like an arse.

[Sandro Seminara]

From looking at the first picture, I'm not sure where the cam seonsor are exactly. Where should I look?

[JBVolvo]

From looking at the first picture, I'm not sure where the cam seonsor are exactly. Where should I look?

added a picture to show where its located on the engine.

in the photo, theres a black cover where the cam position sensor really is.

[Kashif]

Alvin this would be a great one to "pin"