Oil cooler adapter and seals/gasket ...

[TouringBubble]

I'm battling an oil leak that seems to be from the oil cooler adapter I've installed. I got the standard one that comes with only the paper gasket and has the two 3/8 NPT ports. I made the call to use the rubber seals in my gasket set in lieu of the paper gasket thinking they would provide a better seal. These are the orange colors gaskets that seemed to fit the adapter great.

But ... oil leaks heavily when running and is thrown all over the left side of the engine by the fan.

What is the recommended sealing option for this part? The included gasket? Different seals? A combination of the two. I've seen arguments for all options.

The case is a type 1 from a '72 model I believe. The ports on the case seem to be 8mm out from the pump side and 10mm in from the cooler. The adapter has stepped 10mm inlet and outlet.

[FJCamper]

Hi TouringBubble,

Those oil cooler single paper gaskets have always puzzled me. We're all used to the factory seals.

Anyway, I have installed the cooler adapters with paper gaskets and gasket sealer, and it worked. I have also cheated, however, and used fat rubber O-rings in place of the factory seals, with the paper gasket, and that worked as well.

On my first encounter with the single gasket, and with no instructions, I did try both the gasket and factory seals and it leaked. That's what led me to finding some O-rings that fit, and finally, on another install, just using the gasket with nothing but Permatex.

It occurs to ne that if you are trying to use factory seals, you'd have to space the end of the adapter level with a washer, so that as you tighten it down, the seals are compressed evenly.

I wish I had better info for you. This is just a report on my experience with the single gasket.

FJC

PS: We have a private track day at TGPR on 16 August, all day. I can get you in.

[TouringBubble]

Thanks for the info. A universal o-ring might be a better option than the paper gasket alone. I'll see what I can scrounge up at the parts store.

Not sure I can swing the track day with such short notice and the lingering issues with the car. I've got to lick this oil leak as well as whatever fuel/air issue I have that's causing the AFRs to go nuts. I appreciate the invite and definitely keep me in mind for upcoming events. I'm sure I'll have a spare set of tarmac tires to use for these things sometime soon.

[Marc]

I've had a variety of such adapters, from the very first ones on the market which were dead-flat, small-passage and could only work with a gasket through the newest style which are intended to use the 021 117 151A seals, and I have never had an issue with leakage...I'd have to see what you're working with to analyze what's wrong.
A properly-designed late-style adapter should have three "bumps" in the casting to stand it away from the case by the same amount as a stock doghouse adapter; otherwise it'll need spacers as Frank alluded to for that purpose.
If it lacks the bosses, the pragmatic/expedient fix is to go with a cardboard gasket. First be sure that it is dead flat by surfacing it on sandpaper backed by a glass pane. You can source legitimate gasket paper from your F.L.A.P.S. - but the cardboard used on the back of a notepad works almost as well. Cut it to the rough shape of the adapter footprint, making it extra-wide in the area where the passages go. Make the three holes for the mounting hardware (a paper punch is an easy way if you don't own gasket punches) and put it in place, then use a ball-pein to tap around the perimeter of the passages to mark them (the extra width prevents puckering at the edge while you do this, it can be trimmed off later) and trim them out with an X-acto knife, nail scissors, or razor blade. Don't go overboard on the sealant - in fact you should avoid applying any within ~1/8" of the passages - because excess could get into the passages.

[TouringBubble]

Mine does not have the bosses and I have sanded it flat already. I guess that is the issue. I saw no deformation with the seals I used, so I assumed the seals were not being compressed enough, rather than being compressed too much.

I believe I have the gasket that came with the adapter. I'll give that a shot today.

Thanks again for all the help!

[Marc]

I have seen a flat-bottom adapter that used the 021 seals without spacer washers - they made the holes in the adapter deeper rather than provide the bosses. If you have one of those turds, it may not be compressing the seals enough. It could be milled off, but that'd probably cost more than another adapter...and the gasket should work on it.

Now, why are you using one of these adapters in the first place? The stock "doghouse" cooler and fan shroud are superior to almost every alternative, if more cooling is needed a stacked-plate cooler can be installed inline with a full-flow filter. The original use of these adapters was to allow plumbing an oil filter in series with an external cooler in place of the in-shroud singleport coolers of the day. We all thought that was the way to go for a few years, back in the `60s/early`70s - My first VW pal's dad was a machinist at Boeing and made the adapters for us on his lunch hour - but as it turns out this "fool-flow" plumbing is a terrible thing to do.

[Piledriver]

Those adapters can be "fixed" to be actually useful devices...
makes for a great oil entry point from a full flow loop.
The "fix" involves drilling across the passages at the front port, this allows the factory pressure relief to still function...
Either of the NPT ports can be your return point, can also be used for a turbo oil feed or gauge port.
(easier on a T4)

http://www.shoptalkforums.com/viewtopic ... 1&t=139939

[Marc]

...makes for a great oil entry point from a full flow loop.
The "fix" involves drilling across the passages at the front port, this allows the factory pressure relief to still function...

Yes. They also can be used on a dry-sump setup (again by drilling them out or milling a slot to cross-connect the two ports - the latter is slightly less restrictive). But you still don't want to use a singleport shroud because without the restriction of the stock cooler far too much air goes to #3 & 4 cylinders, raising the head temps on both sides. A "doghouse" shroud will still distribute air evenly with the cooler removed. You can simply make a metal blockoff plate to insert in its place (if you think you might ever want to revert to a stock cooler setup), or skin off the doghouse and block the slit that feeds it from the fan.

[TouringBubble]

Basically it's my lack of knowledge on the subject and also the lack of a proper doghouse setup when I started. The original engine had the original doghouse setup but that engine is long gone. The engine I used to start with had no tins, but I believe it did have the doghouse cooler setup. However, I didn't know to hold on to it.

Yes, my adapter is the crap one that has the holes machined deeper to avoid use of the spacers I believe. There was a casting flaw at the edge of one of the places where the seal goes that I was able to sand out. I spent a while sanding it and got the entire surface flat and the flaws gone. At this point I used only a gasket made from the rubber/fiber paper found at the local parts shop. I added a thin layer of gray Permatex to both sides and it's still leaking. I tried to locate some fat o-rings as Frank suggested but to no avail.

My last ditch effort will be to one again try the seals I have that were not being crushed enough, but in conjunction with the gasket and probably black Permatex. With the amount I've shaved off of the casting the seals may decided to work this time. If not, I'll be looking at other options.