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MG MGB Technical - Oil Pressure Relief Valve

Hi All, Not posted on here before (being a midget owner!) but tonight working on my sons 1977 MGBGT we needed to change the oil pressure relief valve but the valve itself wouldn't come out. It appears jammed just where the threaded portion of the hole starts and where the oil gallery is. We tried using a strong magnet but again it wouldn't come out and the end of the magnet broke off and is stuck inside the valve(!) so the car is unusable. My question is how do we get the valve out? Can we reach it by removing the sump and getting to it that way, or is there an easier way? (I'm hoping its not more involved than a sump off job!)

Many thanks, Chris
Chris Hale

You can"t get at it by removing the sump or anything else. Try to get the broken magnet out with long nose pliers. If you"r successful use a piece of round hard wood dowel, very slightly tapered at the end and drive it into the valve. Then gently work it back and forth until it comes out. You will need perciverance but it"s really the only way. Otherwise its engine out to gain better access. Jim
jim soutar

Thanks for the advice Jim. We'll try some long nosed self grip pliers tomorrow and then the dowel technique. Hopefully that will be successful. Chris
Chris Hale

Two ideas that come to mind - if you have a pair of snap ring pliers, you might be able to get a grip on the inside of the valve. Or, barring that and all else, start the engine and let the oil blow the valve out.

Wayne
Wayne Pearson

Another approach is to get a tap started in the valve and rotate it out. RAY
RAY

Had the same problem on my engine. I used a piece of wood with a little epoxy on it, after thoroughly degreasing the stuck valve. Let it cure overnight, and then pulled the valve out.

Tore


Tore

I suggest that you start searching the archives as to how to get the new one IN as well, as that can be something of a challenge...

N
Neil

Thanks for all the suggestions. We managed to sort it tonight. Collected the broken off magnet from inside the valve by use of a large roll pin with hot glue to attach to the magnet and pulled it out. The valve came out by using a large tap with insulation tape round it to grip the inside of the valve. The valve body was scored. We replaced the whole set up but the problem which we wanted to sort still remains which is relatively low oil pressure especially when warm (circa 25 PSI @3,000 rpm).

Chris
Chris Hale

I'd whip the sump off and change the big end shells. Maybe change the pump rotors.
Paul Hollingworth

Replacing the oil pressure valve is "clutching at straws". With oil pressure that low, warm, indicates an engine with excessive ware. Budget for an engine rebuild ASAP. Continued use will only increase the bill. Replacing the big end shells and oil pump will only buy short term relief.

Richard.
RH Davidson

Have you tried another gauge on the engine? It sounds like it always reads low. It would be a pity to rebuild the engine only to find the gauge was reading low...

Mike
Mike Standring

This thread was discussed between 20/04/2009 and 22/04/2009

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