Build9A

Build9A

Well Known Member
Vans Oil Cooler (stewart/warner) mistakenly reported as positech

I've been flying for just about 5.5 hours in my RV9A with left rear baffle mounted oil cooler. I removed the cowling today and noticed a fair amount of oil that appeared to be leaking from the first crease/seam in the bottom of the oil cooler. It was hard to tell because oil was thrown around to make it difficult to determine the real source of the leak. It could have been coming from the lower fitting, but I have removed the cowling on 3 previous occassions to adjust other stuff and it was not leaking from the fitting on previous inspections. Has anyone had problems with the Vans supplied oil cooler? I am going to remove it tomorrow and was wondering if I should send it back, trade it in, go with a different cooler or do some more detective work. I'm 90% sure it's the cooler leaking. thanks, Jack N489JE 5.6 hours
 
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Be Careful

Your symptoms are so similar to mine of last year it is scary. I came to the same conclusion that you have and I still don't know if it was the right conclusion. I replaced the oil cooler (the other type - Niagra I believe) with a new positech and in messing around trying to prevent getting RTV in the end of the hose I hand tightened the fittings and never torqued the lower one. On the next flight I blew out all of the oil by 2,000 ft. and barely made it back to the airport. The engine siezed on the landing roll and I had to pull it clear of the runway. Complete engine rebuild, new chankshaft, all four rods, Prop disassembly, $8,500 and 2 months later I was flying again (with a third oil cooler). I also replaced the oil lines and the fitting installed on the end of the lower hose at the oil cooler may have been leaking. What ever you do (in the way of changes to try and fix the problem), be sure to run the engine with the cowl off before flying to enable detection of gross problems before the situation becomes life threatening. There are oil cooler shops that will test the oil cooler and your hoses for leaks that is probably what a wise person would do. I have to give you the bad news the the shop I went to in El Monte, CA wanted more for the process than a new Positech oil cooler. Like I said BE CAREFUL, this is a very big deal - and watch your oil pressure like a hawk.
 
I had a similar leak that I determined to be comng from the top fitting. I found it by tie-wrapping a piece of shop rag to each fitting before flying. The resulting oil soaked rag segment pinpointed the source of the leak.

Ben Beaird
Plymouth, WI
-6A
 
oil cooler is stewart warner not positech

I mistakenly reported that the problem was with a positech oil cooler. It is a stewart warner, just in case anyone has had similar issues with the correct brand. sorry for the error. Jack N489JE
 
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