Fuel pump connection thread

[markmark2]

Hi all, one of the female fuel pump sockets has stripped, where the banjo bolt fits into the electronic fuel pump which has a plastic thread. Does anybody know what the thread is and the size please. Many thanks. Mark

[nigele]

I’m fairly sure it’s 3/8” BSPP.

Nigel

[richardthestag]

if the thread in the pump has stripped, forget it and get another. fuel leaks could be a bigger issue than the cost of another decent pump.

Do not recall decent pumps having a plastic head

[mole42]

Strangely, this topic came up in conversation at Stoneleigh. The issue is that the new ECCO pumps from New Zealand supplied by several of the respected parts suppliers have plastic bodies and are therefore unaffected by E10 fuel. BUT, the plastic union threads are likely to strip if torqued enough to stop the seals leaking because the 3/8" UNF unions used with the older Lucas pump are too thick to allow enough thread engagement into the plastic body. An effective way to resolve the problem is to have your local friendly machine shop/model engineer use the lathe to thin the unions by about 1/8" (3mm) by skimming off the faces that meet the seals. The union then screws far enough into the pump body to securely hold.

[DJT]

Richard,

I fitted an ECCO pump to my previous Stag without problem and have had one on this Stag since 2010, again without problem. No leaks or stripped threads. Just followed the instructions supplied with them. Are the newer ones different?

[Philip Wardle]

Same experience as DJT - I wonder if anyone in a position to compare the current ECCO offering with an older one?

[richardthestag]

Strangely, this topic came up in conversation at Stoneleigh. The issue is that the new ECCO pumps from New Zealand supplied by several of the respected parts suppliers have plastic bodies and are therefore unaffected by E10 fuel. BUT, the plastic union threads are likely to strip if torqued enough to stop the seals leaking because the 3/8" UNF unions used with the older Lucas pump are too thick to allow enough thread engagement into the plastic body. An effective way to resolve the problem is to have your local friendly machine shop/model engineer use the lathe to thin the unions by about 1/8" (3mm) by skimming off the faces that meet the seals. The union then screws far enough into the pump body to securely hold.

I do love an upgrade* or improvement*



Maybe dasadrew could stick something in the tech forum around fuel pumps and the issues that Richard raises here.

[markmark2]

Many thanks all for your replies. cheers Mark