Last year I replaced my oil pump as preventative maintenance during a rear main seal install. The oil pickup tube has to be press fit into the pump. Tribal knowledge is to heat the pump inlet, freeze the pickup tube, grease both, and install with a wrench as shown below:
It DOES NOT work without damaging the flange / lip on the end of the tube (flange seen in photo #2). I tried 3 different tubes and 2 different pumps. I'm assuming that somewhere along the line the manufacturing tolerances changed to where the fit is now much tighter, or that the High Volume oil pumps (seen in the photos) have looser tolerances. Note: the High Volume pumps require beating your oil pan to fit properly.
The only way I was able to install the tube was by using a $80 installation tool seen below (I tried a similar & cheaper version but it also did not work).
Update: Sorry guys, but the tool has gone missing and I am no longer able to lend it out.
Not trying to hijack, but I think this is relevant to this post.
I thought I read here that it wasn't suggested to use hi-volume oil pumps in the 4.0L.
Can someone verify that?
Brings back memories when I did that many moons ago. Did not know of that tool back then. I used a piece of metal conduit notched to fit that lip, tapping and rotating finally got it flush.
Not trying to hijack, but I think this is relevant to this post.
I thought I read here that it wasn't suggested to use hi-volume oil pumps in the 4.0L.
Can someone verify that?
That is the conclusion I came to last year as well, though I don't remember the specifics. I remember reading you have to beat / bend your oil pan to make room, and some saying it's not a good idea for an engine not built for the increased flow.
Quote: The high volume pump is good if you build the engine for it. You would need a higher volume pan, and then open up oil passages to allow flow to get to the parts you're worried about. A high volume pump should be used when you need to get more oil to the bearing surfaces, usually to the valve train. In addition, you would need to do clean up on the head to make sure oil can flow back to the pan easier. Installing a HV pump and not doing any other work will result in pump drive gear issues.
Unfortunately the knowledge of others is all I had to go off of with this. When I do my stroker build I'll do more research and have a better understanding. However, the logic in that thread makes sense. By all means if you disagree please explain. The more info on this the better.
I just had a buddy use his mutant strength to assemble mine. It's a standard Melling and pushes plenty of volume. 70~75 PSI cold while putting out to the main road in the mornings isn't uncommon.
I just had a buddy use his mutant strength to assemble mine. It's a standard Melling and pushes plenty of volume. 70~75 PSI cold while putting out to the main road in the mornings isn't uncommon.
LOL! I have no doubt your buddy is strong, but I'm really starting to think Melling changed the diameter of either the pickup tube or pump inlet. In almost every past account I've read, people were able to push it in by hand, or use a wrench. The fitment on the multiple pumps and tubes I tried was tight enough that the first pickup installation tool I used crushed the tube's flange / rim simply due to an open end (see below). I'll put it this way... replacing the upper control arm bushings on the axle is repeatedly stated to be a pain in the *** due to the tight tolerances. I just did mine the other weekend, and it was insanely easy compared to the pickup tube.
