Airtex E3372M Fuel Pump Failure

In mid-2010, the fuel level gauge sending unit for our 2000 Pontiac Montana became completely unreliable; the gas gauge would swing from full to empty and back, randomly, at any time.  Money is never all that freely available around here, so it was obvious that this would be yet another do-it-yourself repair, and after some careful shopping online I found an Airtex E3372M fuel pump from a supplier on eBay for about half of the cost that local parts stores were asking.  Since all of the aftermarket brands were priced about the same nearby, I didn't think there would be a tremendous difference in the quality - and we certainly couldn't justify paying well over $300 for an AC Delco or Delphi unit.  (The price at the dealer was even more exorbitant, as expected.)  The pump arrived, and with the exception of the fact that the supplied gasket was much too small (I had to obtain one from the dealer in order to be able to install the pump) the repair went smoothly.  The Airtex pump's pressure was within spec, and the fuel level gauge was working properly again.  The only thing I noticed right away was that the Airtex pump was significantly noisier than the original one, but as it wasn't at a level that was audible when in motion, I didn't really care.

It operated well for about two and a half years.

On Friday, January 11, 2013, while we were on the road from Houston to Atlanta, it began displaying failure symptoms.  The first sign of trouble was stalling immediately after starting in Montgomery, Alabama.  After checking several things under the hood, the engine started and ran near-normally, so we continued the trip.  There were intermittent hiccups at times throughout the weekend, but we managed to make it back home on Monday.  And then, on Tuesday, the failure went past the point at which the vehicle could continue to operate; I barely managed to get it back into the driveway.  A test of the fuel pressure found it was sitting at under 20 psi when the pump was running, and it fell to 0 immediately when the pump shut off.  That pressure is supposed to stay at over 20psi when the pump stops, as an aid in quickly restarting the engine. 

Once it had been confirmed that the problem was in the pump, a replacement was obtained (NOT an Airtex this time). The tank was drained, and the failed pump was removed.  As soon as it was out of the tank, the exact failure became obvious.  The flexible hose that connects the actual pump to the mounting flange had slipped off of the nipple on the pump.  The reason why this was possible was disturbingly obvious; the nipple had no barb of any kind to help retain the hose in place.  This is a clear error in the pump's design; that pressurized connection is pretty much guaranteed to come undone without a barb to provide a physical barrier to hose slippage.  It was not a question of whether the unit would fail, but of when.  Had I noticed this flaw when I was installing the Airtex unit, I might very well have rejected it and sent it back - but unless you're aware of the mistake, and know where to look, it's not obvious. 

Most of the parts stores that sell this pump provide a one year warranty on it.  As the failure involved is a slow one, that means they will get very few of them back under warranty.  Frankly, in my opinion, these pumps should be recalled and replaced with ones that have the defect corrected.  A failure in this part in traffic could easily result in an extremely dangerous sudden stall in traffic, possibly placing the driver and other occupants of the vehicle in considerable danger. 

It is possible that Airtex may have corrected the flaw in later production, but I have not attempted to determine if that is the case.  Certainly, they are still using the same part number for their current units, so I would not expect it. 

I will note that a careful inspection of the replacement - obtained from NAPA, and showing the Carter brand name - revealed that Carter does, in fact, include an adequate barb on their pump output nipple.

Here's a photo of the failed Airtex unit showing the hose that had disconnected itself, and the nipple onto which it had originally been clamped:

Note that the hose nipple (which is just above the end of the hose in the photo) is completely smooth; there's no barb or ridge of any kind there, which there very definitely should be.

I would strongly recommend close inspection of any Airtex brand pumps for this design fault, and unless there is some other mechanism provided by which the hose is affirmatively retained in place, I cannot recommend the use of these units.  The pinch clamp, in the absence of a barb, clearly was not enough to keep the hose from slowly slipping off of the nipple under pressure.  Although there might, theoretically, be some kind of adhesive that could also help to retain the hose, I would hesitate to trust that in the presence of the very active solvent that is modern gasoline.