Why you must change the oil pressure relief valve spring

[ukkid35]

The is where the spring resides, in the oil feed line for the oil pump



If the spring fractures, and you fail to remove all the fragments, then this happens



The problem is that it is impossible to disassemble the oil pump without the casing failing



Not a problem if new casings exist - but they don't

So the only way to repair the oil pump is by finding a donor AJP8 engine - not quick, easy or cheap

Edited by ukkid35 on Thursday 22 July 21:05

[PhilF329]

I hope that isn’t yours that you refer to

Are there any drawings available for the AJP? I know when parts are made for historic aircraft restorations they typically use a 3D scanner to make a digital model and use that to program the CNC, but I would expect you also need tolerances for an oil pump

[spitfire4v8]

I used to change the spring every major service, and always advised others to do the same - they're peanuts in price compared to the possible outcome. It's a bit like fuel pipes though, everyone knows they should be checked and changed but service centres still ignore them. The only loser is the car owner. Always ask if your oil spring is being replaced at the major service, if not ask what else they aren't doing.

[julian64]

With the relatively low value of second hand Cerbs, I fear this sort of failure is going to cause more and more of them to finally retire from the road.

[Jhonno]

spitfire4v8 said:

I used to change the spring every major service, and always advised others to do the same - they're peanuts in price compared to the possible outcome. It's a bit like fuel pipes though, everyone knows they should be checked and changed but service centres still ignore them. The only loser is the car owner. Always ask if your oil spring is being replaced at the major service, if not ask what else they aren't doing.

Who would you recommend as a spring supplier Joolz?

[DuncanM]

ukkid35 said:

The is where the spring resides, in the oil feed line for the oil pump



If the spring fractures, and you fail to remove all the fragments, then this happens



The problem is that it is impossible to disassemble the oil pump without the casing failing



Not a problem if new casings exist - but they don't

So the only way to repair the oil pump is by finding a donor AJP8 engine - not quick, easy or cheap

Edited by ukkid35 on Thursday 22 July 21:05

Bit terrifying that!

Was there a batch of dodgy springs at any point?

[spitfire4v8]

The early silver spring was very prone to failure, the later black springs less so, but it still happens.

new springs are 7 pounds plus vat from racing green. buy one and put it in your car when you next take it for service, no excuse for the service centre not to fit it then.

Edited by spitfire4v8 on Friday 23 July 13:43

[DuncanM]

spitfire4v8 said:

The early silver spring was very prone to failure, the later black springs less so, but it still happens.

new springs are 7 pounds plus vat from racing green. buy one and put it in your car when you next take it for service, no excuse for the service centre not to fit it then.

Edited by spitfire4v8 on Friday 23 July 13:43

Oh thank you for this, I have a black one in a packet here, and it was a black one I last changed .

[Mr Cerbera]

Just in case anyone who reads this doesn't know....

[url]

[julian64]

God I'm old

https://www.pistonheads.com/gassing/topic.asp?t=62...

[Flatplane8]

I remember when this was all fields.........

[julian64]

The sad thing is that this is the first year, first time I have put my Cerb on sorn. Its been on the road legal every other year I've owned it. This is the first year where events have conspired to leave her in the garage.