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MG TD TF 1500 - Cap for oil pressure line on TF

While I search for a plug for the water temp port on the thermostat housing, I have a related need for a cap for the oil pressure line. I plan to send all the instrument clusters out for repair/refurbishment. The speedo and tach can be disconnected at the respective instrument and I can still drive the car with no fluid loss to worry about. However, as with the water temp, unless the oil pressure line is capped, that's going to pump oil out. The location is at the connect point where the small copper line from the oil pressure gauge meets the larger oil line coming up from the block. Again it's finding the cap size and threads that's the challenge. Anyone know what that might be or if there is another workaround?

Thanks,

Jim


Jim Rice

Got any MG friends near you with spare parts. Put an oil gauge from any other British car on the end of the line. Same threads and do you really want to drive the car without knowing whats going on with the oil pressure anyway? Late 60's gauges excluded as they were electrical.
L E D LaVerne

The thread on the union is 1/8" BSPP (G1/8"). You need either a cap with a seal or a cap with a 60° cone to match the union which would be better. Easy to make up if you have access to a lathe. I have some here if you cannot source it locally.

Regards
Declan
Declan Burns

Thanks Declan,

That 1st pic of the cap (with a seal) may work. The 2nd pic of the fitting is fully threaded.

Jim




Jim Rice

Declan:

Received the 1/8 PSPP cap today. Threads on just fine!

Thanks,

Jim
Jim Rice

That solves your problem!
Regards
Declan
Declan Burns

I may have a different concern to resolve. I checked the pressure line cap the other day to be sure I wasn't having an oil leak. I didn't see one, but took the cap off anyway and looking inside. There was no sign of any oil. I looked at the now uncapped end of the connector...no sign of oil in there either. I know I have oil pressure as I can see plenty splashing around the rockers when I take off the oil filler cap with the engine running. But now, I'm wondering if the issue may be related to a blockage somewhere in the external lines between the block, head, and gauge...or elsewhere. If I crack open the banjo bolts one at a time at both the block and head, that should allow oil to seep out with the engine running. If that's the case, then it would point to blockage somewhere in the lines. If no leak...then perhaps a blockage in the block itself. I believe the banjo bolt just threads into the block, and that outlet hole is fed under pressure via an internal passage to the banjo bolt? I've looked at the engine exploded views, but can't see where the oil comes from that feeds the banjo bolt and subsequent external lines.

Could use some guidance here before I try troubleshooting.

Thanks,

Jim

Jim Rice

Jim, have you tried just backing off the cap a wee bit while the engine is running to see if some oil shows up? Bud
Bud Krueger

You know...maybe I overthink things at times. I did crack open the oil line to the head and oil flowed immediately. I then tried the upper connection of the braided flex line, and that also started to flow. Is it possible to have an air-lock where it transitions through the connector to the small gauge line and on to the gauge? All the connections are normally tight, so where does any air in the system go? Is there a bleed process I may have overlooked?

Jim
Jim Rice

Compressed air will read the same as oil, no need to bleed.
J Stone

Thanks Bud/JS

I'll check the connector to see if there is any blockage...then the small oil line. If those flow, that just leaves the gauge, which is why I bought the cap in the 1st place. Mainly to have the gauges restored and functioning properly. Jim
Jim Rice

This thread was discussed between 20/03/2022 and 29/04/2022

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