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MG TD TF 1500 - Pressure relief valve seat

Hi

Just curious how you would replace the relief valve seat.
http://www.mgbits.com/contents/en-uk/p7231_Seat_-_Relief_Valve.html
I can't see how you would remove it, replacing wouldn't be a problem. Has anyone done this?

Barry
B Bridgens

It can be withdrawn by the use of a 8mm stud.
Bela

Hi Bela

Thanks for the tip, I assume that the stud bites into the old seat so you can pull it out.

Barry
B Bridgens

Do you mean the oil pressure relief valve or the oil filter bypass valve?

The pressure relief valve ball seats directly into the oil pump end plate in all engines. It does not have a removable seat. It can be accessed by removing the big brass plug underneath the oil pump.

The oil filter bypass valve seat is a removable brass plug which is pressed into the cylinder block behind the pump on early engines and can be removed with an 8mm thread with 1mm pitch. On the later engines the whole valve is incorporated into a big brass plug inside the oil filter casting and can be unscrewed as a unit. I don't play with the later engines much so I have never dismantled a late style filter bypass valve.

Bob Schapel
R L Schapel

Hi Bob

It's the relief valve seat in the oil pump end plate. This
http://www.mgbits.com/contents/en-uk/p7231_Seat_-_Relief_Valve.html
I figure it must be replaceable as I have just bought one. I think now that Bela must be thinking the bypass with the 8mm stud.
It must be removeable the end plate is cast and the seat is brass or phosphor bronze.

Barry
B Bridgens

Hi Barry,

Wow, I have been "playing" with these engines for about fifty years and I have never noticed that the pressure relief valve seat IS an insert! I learn something new every day! I always just lap a spare ball onto the seat with grinding paste. If your seat is not badly damaged that might be the easiest thing to do. If it is damaged it might be able to be machined back a bit and the spring stretched or packed the same amount as the seat has been cut back. If you want to replace the seat perhaps you could tap a thread inside it (if it is not hardened) and pull it out with a bolt. I would like to bet that very few people have actually REPLACED the seat!

Good luck with the job.

Bob Schapel
R L Schapel

Hi Bob

That's maybe why scouring the internet comes up with nothing. That means it has never been done or it is is so easy that nobody bothers to show you how, I suspect the former. I have bought the seat as I build up parts for my engine rebuild when the car goes for its paint job.

Barry
B Bridgens

Hi Barry,

Yes, I agree with you. I doubt that you will have to use the new seat. Thinking about it I am guessing that they are hardened because otherwise they would have seated the ball directly in the cast iron.

Bob
R L Schapel

This thread was discussed between 24/04/2016 and 27/04/2016

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