Quick question guys. I am changing the oil pump on an lq9 with a melling m295 (original replacement).

The stock O-ring is red but the pump came with a green and black one. The green is the thicker one. The diagram shows that I should be using the green one but it's really tight in the pump. Should i force it in there or reuse the red one?

 

Lube up the green one and wiggle it in there ever so gently. I just installed a green Melling o-ring in my truck. It went in no problem.

 

Lube the O ring as suggested above. The O ring is determined by the pickup tube. From everything I have read the trucks came with a necked down area where the O ring goes, and the cars are straight. I would use the thicker one, and make sure it seats in properly.

 

I used the green one on my install holds great

 

Like said, match the oring to the tube not the pump.

 

Thanks guys the green one went in good.