Leaky oil cooler seals

[AndyMV]

I was prepping my fan shroud ahead of installing it when I noticed residual oil in the cooler leaking out, not from the hoses but past the seals. I removed the sheet metal as well as the washers/spacers and re-fitted the adapter, but it still isn't right. The seals can be moved around freely even with the adapter snugged up. The seals are 021 117 151, which I'm pretty sure is correct. Pictures below:





It looks like the adapter is sitting squarely on the bosses and not on the raised central piece. Adapter is CSP.

Can anyone shed any light?

Andy.

[risk]

The CSP site shows O-rings used here:

http://csplink.de/hd0VmCzph0

But I'm wondering if you could use the thicker oil cooler seals, or even the case stud o-rings that come with the universal type1 gasket kits..

[Marc]

From the picture it does sorta look like the cooler could be high-centering, if not on the hump possibly at the seam.
Nothing in a stock rebuild gasket set is going to solve this. The case O-rings won't be big enough, and the "thick" seals are for pre-`70 Type III with 8mm oil passages, not 10mm. You'll either need to mill the adapter plate down so it'll work with stock seals, or try to find some O-rings comparable to the CSP ones. Seems to me that if VW thought O-rings would work here, they could've saved some money by using those instead of making dedicated seals, but apparently CSP thinks they know better.

I recommend the high-silicone seals (they have a slick look/feel and are usually brick-red or orange). 021 117 151A.

[AndyMV]

Many thanks guys. The CSP mounting kit is a little confusing. The description says it's for a block-off plate, but the images with the o-rings shows the same bypass plate that I'm using. Are the o-rings meant to be used in addition to the seals??

In case it benefits anyone, the O/D of the recess in the adapter plate (where the o-rings in the CSP hardware kit would sit) is 24mm.

[mark-s]

The CSP hardware is for the block-off plate AND the bypass adaptor. Either way, it fits on the original oil cooler location using the o-rings, not the oil cooler seals. Am I correct in thinking that you're attaching it to the cooler instead of the type1 doghouse adaptor? Maybe the recesses in the adaptor plate are designed for the o-rings and therefore too deep for the standard oil cooler seals, so they don't get squashed enough.

[AndyMV]

That's right Mark, I'm connecting the adapter to the oil cooler, which looks like something it was never intended for. It looks like it may work if I can fill in the recesses somehow, but otherwise I'll have to figure something else out.

[mark-s]

Instead of filling the recesses, maybe you could get some material machined off the face, thereby making the recesses shallower.

I had considered doing what you're doing, but instead went the doghouse adaptor route. If you do a google image search for 'golf mk1 gti oil cooler' you'll see that they use the same cooler, and use an adaptor plate to connect the hoses. I was going to get one off ebay and see if it would be suitable - might be worth investigating.

[AndyMV]

Thanks Mark. I went the machining route. Now it looks a little more suitable. I'll post an update when I try and fit it.

20170426150737060 (Copy).jpg

Andy.

EDIT:

This fix worked just fine in case anyone was thinking of trying it.