TR6 TR-6 Fuel Pump Diaphragm Failure [Red-type]

[TRopic6]

I finally installed the fuel pump I rebuilt over a year ago, and in less than 30 miles the diaphragm started leaking. I smelled fuel and found it wet underneath and dripping onto the oil cannister from the weep hole in the pump body.

I had used a kit with a red diaphragm, and it looks like the fuel (ethanol?) somehow separated the rubber stuff from the inner material. You can see where the rubber has seperated and even torn on one side. If you have one of these red ones, better keep an eye on it.

Brosky - great step-by-step on your Fuel Pump 101. I see your kit used a black diaphragm. It looks more substantial than my red one, which seems kind of thin and apparently the fuel started dissolving it (not exactly a good property for a fuel pump). Any problems with yours?

I put the old pump back on, a small, weird after-market one that looks like it was intended for an early Spitfire. It's 20+ years old but at least it works. Anybody else run into a problem with new diaphragms breaking down under ethanol gas? I hope the material in the valves will be OK.

Jeff
74 & 74.5 TR6

 

[Adrio]

I ran into the exact same problem with three kits last summer. Two of them were red ones like your (I bought them from Moss who asked for them back so they could analyze them) and one was a black one I got locally. All three failed exactly like yours did and also in about 30 miles or about half an hour. There is a thread on here about it. Remember to change your oil as some of the fuel may have found its way into the oil sump and now you wont have the proper lubrication from the oil. I found a lot of gas in my oil all three times.

I suspect the ethanol as well.

Moss gave me two new pumps free of charge in exchange for the two failed rebuild kits I bought from them. I have not heard anything back about the analysis. However A friend of mine (who sometimes is on here) has since bought kits from them and the kits seem to have a different diaphragm. I need to ask Frank how many miles he has on the new kit.

I am curious to hear if others are in the same boat.

 

[mrv8q]

FWIW, I believe M*ss was selling the red diaphragm, and T*F was selling the black diaphragm. I rebuilt mine, using the black, but have yet to try it out. Is there higher ethanol content in HA gas, than that stateside?