Guy's just installed a melling high volume oil pump on my 2000 5.3, just started it up for a sec and no oil pressure, everything went pretty smooth I thought, new green o-ring, did drop the pan, shimmed the pump .002 and .003, the only thing I can think of is maybe a screwed up the o-ring on the install, but I thought it was fine, the reason for replacing the pump was sometimes the truck would develop a lifter tick from time to time ( which has been discussed on here) other than that the pressure was good, the only other thing is maybe the shimming? just looking for a little insight. THANKS!

 

Tried pulling the fuel pump relay and just cranking it for a while to see if it will build pressure?

 

No I haven't but I will. THANKS!

 

Are you going by the guage or an oil pressure tester? If you're going by the guage you have to give it time to come up, especially with a new dry pump. As FFDP, said try priming the system and see if it comes up quicker!

 

That's what I'm going to try this morning, maybe I'll get lucky. THANKS!

 

Keep us posted, hope it just needs a good prime.

 

No luck with the priming guy's, just going to tear it back down, you would think though you should have some pressure? THANKS!

 

Sounds like you may have a oring issue.

 

I just saw a similar issue from a local shop that pulled the pump and the spacer plates for a double roller were installed incorrectly so check those if you have a double roller.

If that was the only thing you changed then definitely o-ring, but don't forget to check the front plug too

Also - I packed my pump with petroleum jelly to help with priming - instant oil pressure almost

 

Sorry guy's been out of town a few day's, I found the problem and it was my screw up, the flange that's on the pickup tube that bolts to the pump is not flush, when I took it apart it was like this as well, dumb *** me put it back that way, stupid, just wasn't thinking and this is the first one I've done ( well done a camshaft swap on my LS2 69 Camaro)So got it tore down and ordered a new melling pickup tube, something just isn't quite right about the old one, going to start putting it back together tomorrow, I'll post back up. THANKS!