Oil pressure relief valve piston identification .

dogdog1 · Post by **dogdog1** » Fri Apr 06, 2012 10:14 pm

Hi , This might sound like an odd question , but when looking down the bore in the oil pump how do you tell if an oil relief piston is actually there ? I can see a narrowing just below the threads and what looks like a second narrowing further down . I cant make out if this is the piston or just part of the bore . It doesn't want to move at any rate . It came with a used Rover V8 I bought . Thanks , Gerry .

ChrisJC · Post by **ChrisJC** » Sat Apr 07, 2012 8:15 am

The piston is cup shaped, so you should be able to see a reasonable step at the top of the cup, then a blind hole the size of the spring.

Presuming this is a distributor driven oil pump?

Chris.

dogdog1 · Post by **dogdog1** » Sat Apr 07, 2012 4:25 pm

Thanks Chris , I must be looking at the piston then , as there is a step behind the threads and then a second step further down . Presumably the bore would be the same width all the way down if no piston was in it ?

ChrisJC · Post by **ChrisJC** » Sat Apr 07, 2012 5:37 pm

I can't quite recall, but I think if there was no piston, you'd be able to see out of the bottom? Not sure about this though.

Chris.

mgbv8 · Post by **mgbv8** » Sat Apr 07, 2012 8:09 pm

Why dont you just undo the cover nut and see if there is a spring and piston inside??