Oil Pressure Gauge Pipe Leak

[Bass1st]

My 4 1/4 sprang a leak today under the dash, depositing oil on my nice new shoes. It looks like its leaking at the bulkhead end of the pipe, where the pipe enters what looks like a nut.

Before I start messing with it, is there anything I should know about the pipe or the connection itself? Not sure if anything is soldered down there for example.

I did have the dash out to repair the light switch so I guess either something as loosened up or broken.

[Bass1st]

I took the pipe off and it looks like it had been repaired previously, and not particularly well.

I will try and source a replacement pipe.

Does anyone know the part number or what type of threads are used?

[Christopher Carnley]

The pipe extends from the oil pressure connection on the main feed on the side of the crankcase.

The bulkhead connection is a nipple silver soldered onto the pipe, 4 mm copper in this case, with a back nut.

From memory,as it is 8 years since I fitted one, the threads are 1/4" BSF, British Standard Fine.

All smaller threads are BA, British Association, on the Derbys, they are 1BA and odd sizes down to 7BA.

[Bass1st]

Thanks, that's great. The photo matches the end of the pipe at the gauge. The end at the bulkhead also has a retaining nut but seems to have a tapered end, rather than a flat surface?

[Christopher Carnley]

That is how it was made. There is a complementary shaped recess in the nipple, for location and sealing.

Don,t file it flat.

[Bass1st]

OK, thank you. I can see the corresponding shape at the bulkhead. Just hope I can find a replacement. The Bentley spares scheme have been unable to help.

[Christopher Carnley]

Try Fiennes Parts, new owners new website.