Rear Main Seal Leak 88 760

DeRail · Post by **DeRail** » 29 Mar 2009, 19:44

Slight update, I've been researching the PCV system on my 760 and what I've discovered is that there is no breather box like the 4cylinder, simply the breather on the top of the oil cap. Also, as far as the oil leak, I'm beginning to wonder if it really is the RMS, because I was looking where the oil stain is on the driveway the other day.

I noticed that it appears to be about where the splash shield underneath ends. I'm wondering if there's a leak in the front of the engine and it's leaking down into the splash shield. I looked at the distributor cap and I didn't take the plastic shield off, but it looked like there was oil leaking, I could see fresh oil on one of the hoses under it.

Before I started to try to do my own work, I had a mechanic about a year ago do a new cap/rotor. Is it possible the oil would be leaking from the distributor cap, or would it be from further down the distributor?

Thanks

Post by **billofdurham** » 30 Mar 2009, 12:40

That is what I call an easy PCV. When things get choked up wash out the filler cap or, in extreme cases, replace it. No need to take half the engine off to get to it. Ah, the good old days.

Having said that my first two cars had no PCV system just an open ended pipe down the side of the engine. At times more smoke came out of that than from the exhaust. The even older days!!

The distributor on the 700 series in general is prone to leaks. There are two O rings on the distributor, a large one on the housing where it sits in the engine and a small one on the end of the shaft. The big one is most likely to leak. There is also a centre shaft seal inside the distributor which is very difficult to change, if you can get one. If the centre shaft seal is the culprit you will have oil inside the distributor and it will be leaking from the cap.

The seals and O rings are not listed on VADIS but they may be available at:http://www.rprusa.com/index.html.

Bill.

DeRail · Post by **DeRail** » 30 Mar 2009, 22:24

Bill, I am lucky, so far this vehicle has been very easy to work on for a beginner. I've done a little research into removing the distributor to replace the seals. Do you think I'll have to re-time the engine if I mark where the distributor is sitting before I take it off? I've never done anything like this before, but is there any way to be sure which seal it is before I pull the distributor out?

Thank you!

Post by **billofdurham** » 31 Mar 2009, 12:15

You can eliminate, or otherwise, the centre shaft seal by removing the cap. If there is oil in the distributor then it is most likely that seal that is gone. Next check around the body of the distributor where it sits into the engine. If the large O ring is the problem you will have oil on the outside of the engine at that point and running away from it. The small O ring can't be checked without removing the distributor but its main purpose is to stop oil going up the shaft and into the distributor. So, no oil in the distributor would indicate that it is OK.

Marking the position of the distributor will help to keep the timing right, however (there's always one of these), pull the distributor straight out, note the position of the plate, rotor and offset drive cog. Draw a diagram or, in these technological days of digital cameras, take a photograph so you can reinstall everything correctly and not 180 degrees out of alignment. The distributor may be tough to remove as the body is aluminium and may be stuck in place. It will come out, usually in a rush and with battered knuckles on your hand.

When replacing the O rings use a little Vaseline to help get them on. Put antiseize on the bolts and a film of antiseize on the distributor body to make it easier to remove if you need to do this again in the distant future.

Bill.

DeRail · Post by **DeRail** » 02 Apr 2009, 19:01

Little bit of an update

Took off the small plastic housing on the dizzy cap and it appears there is oil coming from the underside of the housing that touches the engine. My question is: do you think I'll have to remove the radiator to pull the distributor out far enough to replace the seal? Also, I was looking around the engine bay for sources of leaks and noticed on the right side of the engine there is some sort of what looks like a drain, with two bolts and what I would think is a gasket. There seems to be oil coming out of there as well, any idea what this is so that I can get a new seal for it and look it up in the manual to see how to fix it?

Sorry for all the questions, I'd just like to nail these oil leaks down because whilst I'm not losing a noticeable amount of oil, I'd like the peace of mind

Thanks!

Post by **billofdurham** » 03 Apr 2009, 12:25

What is the clearance between the distributor and the radiator? There is not much behind the distributor to pull out. The time allowed for distributor R & I is less than 0.4 hour so it can't need too much other work done.

I like the photo. I haven't a clue what the part is but the picture is very clear.

Bill.

DeRail · Post by **DeRail** » 03 Apr 2009, 16:54

Bill, I'll have to check the clearance. I've never pulled a distributor so I wasn't really sure the length of the unit itself. Also checked with RPR Volvo and they are unable to get a hold of those seals... I've sent an email to FCPGroton so hopefully they can locate them.

billofdurham wrote: I like the photo. I haven't a clue what the part is but the picture is very clear.

Thanks, I used my buddy's Apple iphone to take it

I'll have to do some more digging and see if I can't find anything on it

How safe is the VADIS that they sell up on ebay? I'm looking to grab a copy because the instructions and stuff would be handy IMO and I wouldn't have to keep asking you guys for part #'s.

And as always,
Thank you Bill and MVS!

Post by **billofdurham** » 04 Apr 2009, 12:19

VADIS is good for part numbers for the older cars but has no repairs for them. For later models the repair sections are very good.

All VADIS discs sold on eBay seem to have come from one or two originals and have been passed around by others jumping on the bandwagon to make a few pennies.

They have always been cheaper on the UK site and are even cheaper now for US buyers because of the exchange rate.

However, you would only be buying for the part numbers for your car and that bit in your photo isn't listed!

Bill.

DeRail · Post by **DeRail** » 04 Apr 2009, 21:55

Hi Bill,

I know that VADIS doesn't have that thing on the engine listed, but I was just thinking instead of calling up the dealer or a partshouse and asking for the whatchamacallit between the two dohickeys. But, maybe I'll just hold off on that.

Once I find out if I can get the seals, I'll report back

thanks!

DeRail · Post by **DeRail** » 30 May 2010, 14:58

Well, I got to work on the AC today but it seems I've run into another issue (what else is new!

)

I found the leak and it is in the u-bends of the condenser, so the unit will need to be replaced as far as I know. While I was under there I noticed that there was a considerable amount of oil coming from the space between the distributor and the engine. I contacted rprusa last april but they didn't carry the part. Any recommendation on what I should do to either locate the correct o-ring or find a replacement? No oil in the cap itself, it's just coming out that outer lip.

Thanks,
Darrell

Rear Main Seal Leak 88 760

Re: Rear Main Seal Leak 88 760