Ok I have a silverado 1500hd6 with a 6.0 and the other day I had no oil presure and then it would jump to 30 psi. So I bought a presure switch and that wasn't it either. Now im replacing the oil pump since I don want to pay a shop $350 in labor. So I know I have to drop my transfer case. But when installing the pump do I have to remove the coolant and water pump?

 

Unfortunately to remove the timing cover, you will need to remove the waterpump and drain the coolant...

 

have you checked your oil level? i've seen low oil cause erratic oil pressure.. obviously

 

Yes I did. I even put new oil and filter in just yo make sure it wasn't a collapsed oil filter. From what I read and the symptoms my truck has it sounds like a broken o ring. Can this be installed with out removing the timing cover? I rather keep it as simple as possible since I only have about 2 hours each day I can work on it.

 

Ok dude....the only thing you can do WITHOUT removing the timing cover is remove the crank pulley. You got some work to do, get it done.

 

I believe the o-ring can be changed by pulling just the oil pan and not the front cover. If you need to change the pump and you need to pull the front cover, which means pulling the water pump, crank pulley, etc.

 

Well dropping the fronttransfer diff tonight. Will just unbolting the front diff and supporting it with a jack and lowering it be enough to remove the oil pan or do I need to unhook the axles?

 

I've changed oil pump and oring many times on the 4x4's without dropping the front diff, just have to remove most of the front bolts on the oil pan and loosen the back ones. The front cover definitely has to come of to do it this way.

 

op your original problem sounds like the pressure relief valve in the pump is sticking open (possibly some trash got past the pickup screen).

 

Ok so I bought a melling m295 oil pump. Pretty much a stock replacement right? Also ut came with 2 different size orings. From what I read I want to use their green one right? Its smaller but thicker. Also I have a new gm red o ring. Can I use both the gm red o ring and the melling green one to insure that it wont break in the future? Also when I pulled out my coolant it was green shouldn't gm have the red coolant? And I bought new water pump gasket. Can I reuse my oil pan and timing cover gasket?