1998 V70 XC Leaking engine oil cooler lines

[scot850]

The 2 engine oil cooler lines from the radiator, are leaking from the join in the little manifold below the crank pulley. They are sealed with an 'o' ring which slides over the end of a metal pipe with a ridge on it to stop the o-ring sliding up the pipe. Both pipes are help in place my a small metal plate that sits behind the ridges of the 2 pipes and bolts in place with a single bolt. These O-rings have been replaced twice in the last few months and it leaks again soon after. The dealer mechanic says I need to replace the pipes to fix it, but I struggle to understand why they should leak at all.

Has anyone come up against this problem and know of a possible fix, or can suggest a fix?

I really don't want to shell out $250 on 2 new pipes.

Thanks,

Neil.

[jreed]

I have a '97 855 which may be slightly different from your '98, and I didn't have leakage at the oil thermostat as you are describing, but I have replaced the oil cooler lines and can see why they might be prone to leakage if they are damaged or not cleaned up and reinstalled correctly with the right o-rings. I wrote up a description of the removal and replacement of the lines (linked below) that shows a lot more detail on the lines and o-rings as well as the clamp that holds the lines in the oil thermostat.
There are a few possibilities for the leak. If you disconnect your lines from the oil thermostat you'll be able to see if the tube walls are scratched or you have damaged o-rings or a bent clamp, or the sealing surface on the oil thermostat is damaged. Do you have seeping or leaks in any other part of the lines? If so that might change the direction you would want to take to make a lasting repair.

https://www.matthewsvolvosite.com/forums ... 4&p=282639

[scot850]

The lines themselves are bone dry. There is a weep from around where the lines enter the thermostat housing (thanks for the correct name). I'm guessing as the dealer has had 2 goes at it, it is time for me to do it correctly and pull the lines and look at the suggestions you have made. Many thanks.

Neil.

[cn90]

I outlined my experience in the thread below. Brand-new O-rings installed by dealer leaked after 2 years, so I had to redo it myself.

Even with new green O-rings and retaining plate in place, I could still rotate the metal lines. So it was not a tight fit. If it is a tight fit, I should not be able to rotate the metal lines.

The bottom line is: if you flip the retaining plate around (see the photo from 08 Jan 2014), it should improve the situation.

https://www.matthewsvolvosite.com/forums ... =1&t=36007


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Anyway, at the moment I have no leak, but if I have to redo this again, I have a few ideas:

1. Inserting a very thin washer between the "flange" on the metal line and the green O-ring, or...

2. Inserting a thin washer between the retaining plate and the "flange" on the metal line.

The idea is to put a bit more pressure on the green O-ring for a better seal. Anyway, this is just a thought, see photo below:

Washer.JPG (15.66 KiB) Viewed 519 times

[scot850]

Funnily enough I was thinking the same as you on this. First thing will be to remove the bolt, flange and pipes to see what base material I'm working with. The foreman at dealer said that over time, the original 'o'-ring becomes hard and leaves a little depression on the pipe and so doesn't put sufficient pressure on the 'o'-ring to seal properly, so replacing the pipes is what they do. I think with a little experimentation, a fix would work, but looking at how it all fits together first will set me up for which way to go. I will photograph and post how it goes, so if what I do works, then we have a write up.

Thanks again cn90!

Neil

[scot850]

As I had to order parts from Tasca for our 06 XC70, I ordered new oil cooler pipes as well. They are half the price in the US than in Canada, so if I don't need them I'll sell them.

Neil.

[cn90]

FYI,

Oil cooler or Trans Cooler lines can be rebuilt at home for $10 (for both) using generic oil hose sold by the foot at local parts store.