To Replace Oil Pump or Not To Replace Oil Pump?

[88mancheman]

Hey all I’ve been pondering this question for a while now, Ive been in need of an oil pan gasket replacement for some time now but it hasn’t been till recently that the leak has gotten bad enough to warrant being fixed, now here is the kicker, I’m at about 220k possibly more lol (odo stopped long time ago) she runs good has great oil pressure 35-55psi all the time, solid 14-16 vac at idle and sounds healthy.... but along with the RMS that isn’t leaking yet inner me feels like I should replace the oil pump while I’m down there... what are your opinions on replacing it?

[Minuit]

I'd at least replace the gears. There's a kit you can buy with the gears and gaskets.

 

Sloppy gear clearances caused the oil pump in my 89 to lose its prime, causing a sudden complete loss of oil pressure. That engine was already garbage so it wasn't the end of the world, but if the engine was good that would've been a real shame.

[omega_rugal]

 

18 hours ago, Minuit said:

I'd at least replace the gears. There's a kit you can buy with the gears and gaskets.

 

this. clean any sludge that may be stuck there, check for worn gears, replace gaskets...

[AZJeff]

Oil pumps are pretty cheap.  They run $25-75, depending on brand, on Rock Auto.  If there is any doubt, spring for a new pump.

[88mancheman]

I'd at least replace the gears. There's a kit you can buy with the gears and gaskets.
 
Sloppy gear clearances caused the oil pump in my 89 to lose its prime, causing a sudden complete loss of oil pressure. That engine was already garbage so it wasn't the end of the world, but if the engine was good that would've been a real shame.

Is there any advantage to rebuilding the pump VS replacing it? Seems like the new Melling’s ones are only $12 more

[Minuit]

10 minutes ago, 88mancheman said:

Is there any advantage to rebuilding the pump VS replacing it? Seems like the new Melling’s ones are only $12 more

Not really. I think I remember it being quite a bit cheaper to rebuild it back a couple of years ago when I was doing this on my 89. Does the new pump come with the pickup tube? For $12 more if it comes with the tube, I'd go for the new one.

[ghetdjc320]

17 minutes ago, Minuit said:

Not really. I think I remember it being quite a bit cheaper to rebuild it back a couple of years ago when I was doing this on my 89. Does the new pump come with the pickup tube? For $12 more if it comes with the tube, I'd go for the new one.

Especially if the pickup tube is pre-installed lol. That’s a tedious job. I tack welded mine in place once I got it installed so I knew it would never budge

[omega_rugal]

if it works as it is a simple rebuild is enough, cleaning and a new gasket, even the cleanest pump gathers dirt after all these years, gaskets go bad overtime, its inevitable

 

if you go for a new pump make sure you get a good brand, there are many chinese knock off around you don't want

[88mancheman]

Not really. I think I remember it being quite a bit cheaper to rebuild it back a couple of years ago when I was doing this on my 89. Does the new pump come with the pickup tube? For $12 more if it comes with the tube, I'd go for the new one.

I had completely spaced the fact that a new one would need a pickup tube aswell that is an extra $20 lol

[88mancheman]

Especially if the pickup tube is pre-installed lol. That’s a tedious job. I tack welded mine in place once I got it installed so I knew it would never budge

I think I might end up going with a new Mellings pump just for piece of mind, but I’ve heard a few horror story’s on the forums of the pickups not sealing 100% on the new pumps is there some trick to getting them to seal? Some sort of anaerobic sealer & a good tac weld I’m guessing?

[ghetdjc320]

It’s a press fit. An open ended wrench that barely slips over the tube normally works. Put the pump in a vise and use the open ended wrench to tap the tube into the housing. Or better yet, get the tool for it. Once it’s all the way in you can hit it with a single rack weld for added security but it’s not a necessity. 

[silvertwinkiehobo]

Don't forget to prime the pump; I use some kind of honey oil, like Hy-Per-Lube to prime it. I add enough to fill the top of the pump, then turn it backward for the gerotors to suck in the oil. Also, while down there, rotate the crank, look carefully for any indications of any damage on the rotating assembly.