oil pump rebuild

Jimbo

1978 260z in yellow
Club Member
i have a gasket and bolt kit from mike to fix a very small weep from the oil pump.
if anyone has any advice and tips on how best to remove the pump and pointers on things to look out for and check the pump while its off the car.
i have read the haynes manual on the subject but im finding having to remove all the distributor and lining up the shaft between pump and dizzy a bit daunting.
how difficult is this job and is it best left to someone more experienced?:bow:
 

jonbills

Membership Secretary
Site Administrator
It is very easy. Nothing at all to taking it off and putting it together again just means setting engine to tdc, lining the dots up on the pump&drive and slotting it in (with a bit of a twist as you go). You know when you've got it right because the distributor tang is in the right place.

In terms of checks while it's off, you can easily remove the pressure relief valve cover and check
The plunger moves and all is clean, but if you want to do more and take it apart you'll need another gasket and the fsm instructions for checking clearances - which is also easy but not sure if Haynes covers it
 

Farmer42

Club Member
It is very easy. Nothing at all to taking it off and putting it together again just means setting engine to tdc, lining the dots up on the pump&drive and slotting it in (with a bit of a twist as you go). You know when you've got it right because the distributor tang is in the right place.

In terms of checks while it's off, you can easily remove the pressure relief valve cover and check
The plunger moves and all is clean, but if you want to do more and take it apart you'll need another gasket and the fsm instructions for checking clearances - which is also easy but not sure if Haynes covers it

Ditto, what Jonbills has said. If you are careful removing the pump without allowing the drive shaft to drop out, it should be easy to put back in the right place. A tip is to put a bung into the hole to stop it dropping. Get the engine to TDC on no. 1 cylinder first and make sure it doesn't move.

If you do take it apart and feel inclined to check the tolerance measurements for the rotors they are:

Rotor End Clearance - 0.0024" (0.06mm)
Cover to body clearance - 0.0016-0.0032 (0.04-0.08mm)
Rotor-Tip Clearance - 0.0047 (0.12mm)
Outer rotor to body clearance - 0.0059-0.0083 (0.15-0.21mm)

The are taken from the 'How to rebuild your Nissan & Datsun OHC Engine' book.

Check for grooves or scoring on the outer rotor and casing by scraping your nail across the area and if you can feel a ridge, chuck it and buy another one. You could try to remove them with fine emery cloth but you risk increasing the tolerances and making an oval so I would avoid if possible.

When you put it back together if it is ok, you should see 2 arrows on the rotors these must line up and they should not be visible when you put them back into the body.

Good luck.
 
Top