After pressure testing the cooler and hoses it appears I have a oil leak at the seal between the 16mm to AN-8 steel adapter and the 1st gen early model cooler threaded bungs. When the system was first put together Stat-O-Seals were used but they began to leak after about 5 weekends even after subsequent tightening. It appears the flange on the fitting has an OD that is not much bigger than the rubber insert of the Stat-O-Seal.

Yesterday, after putting everything back together and using aluminum crush washers it leaks even worse. OEM crush washers are NLA. I have not tried Dowty seals and am concerned because the AN sized units have an ID that is a bit larger than 16mm. There are metric sized pieces but Google showed only a place in the UK and Australia.

Any ideas?

 

when you tightened the new fittings onto the bungs, you cracked the bungs. this is very comon. the fittings do not need to be tightened much past snug (once bitten twice shy on this). you will need to remove the oil cooler and have the cracked bungs tig welded or replace the oil cooler. when you remove the oil cooler you'll be able to see the cracks. may be even more noticible if you remove the fittings from the bungs. often times you'll see the split is completely through the bung and into the threads..if you need pics of a cracked cooler let me know. i've got three on the shelf

 

A relatively easy way around this is to get two weld on -8 AN fittings - http://www.holley.com/997108ERL.asp - and have the bungs cut off and weld these in their place. I had dj55b weld these on mine and have had no problems at all. Not one drop has leaked since this has been done. This is quite an improvement since you dont really need to worry about cracking the bungs anymore, as well as not needing washers either.

 

The cooler was removed, inspected and pressure tested using the old sta-o-seals. No cracks, no leaks. Since the stat-o-seals will eventually leak as proven before I replaced them with crush washers. They leaked immediately.

I have ordered some Al 16mm to AN-8 adapters and dowty seals from Summit. If those seals fail I will remove them, screw in the adapters and weld them.

Any precaustions for welding anodized fittings to the oil cooler?

 

i would just make sure the fittings and the oil cooler are both clean bare metal before welding. this is an excellent alternative.

 

or you can just upgrade to a second gen oil cooler. trochoid has an excellent write up on how to do it.

:AA: