Oil pump overhaul - thoughts on acceptable marks?

[MLCstag]

I've taken the opportunity to overhaul the oil pump and fix a leak whilst changing the exhaust. Now having dismantled and cleaned the oil pump to examine it I have found that the wear is well within the ROM limits However, the end face of the rotor has some score marks from cruddy oil (this is a common issue I have found as I overhaul engine parts as the engine has stood for long periods in its life).

So, my question to you all is what are the thoughts on the acceptable amouts of scratching? Also, can the ends be dressed to take away the scores?

Thanks in advance.

[Ian Durrant]

You can lap the end plate on a sheet of glass with wet and dry laid on it to get rid of the score marks. Other than that if the pump measures as too worn (ROM and Haynes give details on how to check with feeler gauges) then you need a new pump anyway.

[Lingen]

Hopefully you will find that the wear on your pump is within acceptable tolerances, but I would like to offer a word of warning if fitting a new one. Using the bolts that attach it to the block, get four appropriate nuts and washers, and do them up tight to pull the pump together as it will be when fitted. Then check to see that it is still free to rotate. It is not unheard of that they get so tight when compressed that they can shear the drive when starting the engine.
I wonder how I know?
Mike.

[jleyton]

I see that you say your wear is well within the ROM limits but I can appreciate you wanting to get rid of the score marks on the rotor. If you do as Ian has suggested I'd recommend doing the same to the alloy pump body to avoid creating too much end clearance - if that makes sense ?

Cheers

Julian

[Ian Durrant]

Unless my memory of the stag pump is very faulty, lapping the alloy end plate won't create any extra end clearance? if the rotors are scored then I think a new pump is in order anyway.

[jleyton]

You're absolutely right Ian that lapping the end plate won't create extra clearance.

However rubbing away the scores on the rotor could create extra clearance between the rotor and the end plate and it will be necessary to fractionally reduce the height of the alloy BODY (and the circular rotor) to overcome this (and then be especially careful of what Mike has warned of)

Cheers

Julian

Ps We may be at slightly cross purposes ! MLCstag was talking of scoring of the rotor, rather than the end plate, which could be removed as you suggest.

[MLCstag]

Hopefully you will find that the wear on your pump is within acceptable tolerances, but I would like to offer a word of warning if fitting a new one. Using the bolts that attach it to the block, get four appropriate nuts and washers, and do them up tight to pull the pump together as it will be when fitted. Then check to see that it is still free to rotate. It is not unheard of that they get so tight when compressed that they can shear the drive when starting the engine.
I wonder how I know?
Mike.

Thanks to all for the advice. I've put the pump back on having done not much more than a clean and new sealing rings. My rationale is that the clearances were fine and the scratching on the rotor was more of a cosmetic concern and I can't see it reducing oil pressure.

Now the concern is priming and confirming the pump is running as I do not have a pressure gauge fitted. I read somewhere on the forum that cracking the seal on the oil filter and turning it over until oil weeps out is a good way to prime the pump. It will also confirm the oil pump is pumping, but is this really necessary?

Brian

[MLCstag]

Pictures

DSC08798.jpgDSC08799.jpg

A couple of pictures of the marks for anyone else in the same predicament.

[tractorjames]

When I change the oil, I disconnect the coil and turn over till the light goes out, then turn over for another few seconds then fire up! I believe others have made up a longer shaft to run the pump up off a drill.

James

[wilf]

I prefilled my oil pump with oil before refitting it. It solved all the priming issues as I got oil pressure very quickly after spinning her over (all plugs out)

[V Mad]

I think Vaseline works well

(for priming the oil pump )

[jleyton]

I'm a great believer in running up the pump first on the pump drive.

You only need to remove the dissy and fit a battery drill, with a hexagon socket, onto the pump drive. You can then run the pump to your heart's content and rest assured that the oil is being pumped to all the important places, whilst no parts (crank, pistons cam gear etc) are moving unlubricated.

You have to run it anti clockwise and I use vaseline as has been mentioned.

Good luck. Cheers

Julian

[MLCstag]

I'm a great believer in running up the pump first on the pump drive.

You only need to remove the dissy and fit a battery drill, with a hexagon socket, onto the pump drive. You can then run the pump to your heart's content and rest assured that the oil is being pumped to all the important places, whilst no parts (crank, pistons cam gear etc) are moving unlubricated.

You have to run it anti clockwise and I use vaseline as has been mentioned.

Good luck. Cheers

Julian

Think I need to give this a try but need to get a bent spanner sorted for that awkward distributor bolt! Time I got round to it.

Cheers for for all the suggestions. I also used Vaseline and filled the pump with oil

[jleyton]

No need for a bent spanner, just unbolt the coil and then it's easy to remove distributor.

To make things easier for the future you can reshape the coil retaining holes into an inverted U shape and then you'll only need to slacken the bolts to remove coil.

Cheers

Julian

[MLCstag]

No need for a bent spanner, just unbolt the coil and then it's easy to remove distributor.

To make things easier for the future you can reshape the coil retaining holes into an inverted U shape and then you'll only need to slacken the bolts to remove coil.

Cheers

Julian

Like that one Julian, thinking outside the box. I've had the coil off a number of times and its a 'b' to get the bolts back in. Why didn't I think of the inverted U hole idea.

Brian