Hi Scott,

 

I have used the MDS inline fuel pump (very similar to the ones Tracy sells).  I have used them for over 10 years and never had them leak.  They use (what used to be called "Saginaw fittings - I think because they were metric and used in Automobile fuel systems" - with the small "O" ring.  In fact, it looks exactly like the summit racing part.   There is always the possibility you got a defective fitting or an old  "O" ring.

 

Ed

From: Scott

Sent: Wednesday, June 29, 2011 9:56 PM

To: Rotary motors in aircraft

Subject: [FlyRotary] GSL393/74028 Fuel Pump Replacement/Fuel Leak

I have inline fuel pumps from Tracy from a while back.  They were from Napa and were the 74028 flavor( http://www.summitracing.com/parts/CRT-P74028/?rtype=10 seems most like them currently ) Tracy used to provide. The fixed hose barb side of course does not leak, but on the screw fitting side I have a 10mmx1.0( http://www.summitracing.com/parts/RUS-670480/ ) with an o-ring and everytime I think I have the fuel drip fixed and start the pump without the engine it doesn't leak.  But, after a short engine run the drip returns.  As I burned out one of the pumps already( important safety note make sure the fuel selector valve is not off while you have the pump turned on and are checking for leaks ) and will need to replace it what other inline pumps have folks been using?  The 74028 flavor fuel pumps, the 10mm fits but does not seal.  I did not use thread tape or other thread sealer.  And no amount of tightening seems to keep it from leaking again. Thoughts on a fuel pump substitute?  Way to seal that fitting to the existing 74028 pump? Thank You. -Scott http://n820wa.blogspot.com/2011/06/engine-runs.html