Melling problems

[dusterny]

My engine has new Melling oil pump on it. A friend and I took a new pump out of the box poured some oil in it and installed on engine. We used no silicone just paper gasket and some oil. Install was done so we were going to prime pump before firing engine. Had trouble getting shaft into pump so filed a lead on hex. Got it to go in and put electric drill on it and spun it. No oil pressure. Pulled prime tool out and first half inch of hex is rounded off. Oil pump won't turn at all. Looks like engine has to come back out and oil pan off. We can't think of anything we did wrong or why a new pump is bound up. We followed all torque spec. Did we screw up someplace? Done this with lots of oil pumps and not had problem till now.

 

[dodge freak]

Maybe some junk felled in to the pump. Where did you get the pump from / places like Summit-Jegs allow returns and you might haven't gotten a returned pump--that somebody messed up.

My old engine teacher from the 80's told us you should always take the cover off a new pump and check the clearances. Claims they are not always right. Do I, nope but if you do have to yank the motor back out I bet you look over the oil pumps better from now on, lol.

Did you spin the pump gears or just pour the oil in, you should had spun the gears too.

 

[fishy68]

This is why I disassemble and check all oil pumps. Can't take anything for granted anymore. Last Melling pump I bought was really sloppy machined. I noticed it right when I took it out of the box. Rattled like it had rocks in it. I use Sealed Power pumps now. Their mounting flange is even thicker and heavier made than a Melling pump. BTW: you should be able to drop the pan and change the pump. I did on my Cuda. It's tight but do-able.

Only thing that might have happened is when you installed it you didn't get it seated into the main cap good. I had one not seat in the cap and bind up on me once but I noticed it cause the pump wouldn't tighten down correctly.

 

[dusterny]

I might try to drop the pan with engine in the car at this point I have little to lose. Do you have room to take whole pan out ? I am really wanting to know what went wrong.

 

[fishy68]

If you unbolt the motor mounts and jack the engine up as high as you can the pan will come out. Watch the dist when you jack it up. I had to pop the dist. cap off cause it was hitting the firewall. You also have to drop the center link. I popped off the center link and tie rods as a whole unit. Made a lot more room.

 

[moper]

Yeah, check every pump and the last couple I've tried to make sure teh oil pump drive goes in easy. The last one I did I needed to lightly de-burr the hex on the pump for the drive. I've also found chips in them, especially the pressure relief.

 

[alsdemon]

same deal with a melling pump was in stalled in a 351m very little use, pump locked up broke dist. gear took year or 2 to find out what was going on. installed used o/e pump from a job my step dad got me.:cheers:

 

[slippery440]

I am his friend that installed the pump. I am a dumb farmer that trust professional people to stay within the specs. Once I get the pump out and find out what happened I will have Bucky post.If its a junk pump I really hope Melling has a good PR program.I will make sure that they will compensate Bucky or have a real pissed farmer with access to a computer.

 

[Cudafever]

I am his friend that installed the pump. I am a dumb farmer that trust professional people to stay within the specs. Once I get the pump out and find out what happened I will have Bucky post.If its a junk pump I really hope Melling has a good PR program.I will make sure that they will compensate Bucky or have a real pissed farmer with access to a computer.

It my be a bad pump, BUT i thing fishy68 hit it on the head!

Only thing that might have happened is when you installed it you didn't get it seated into the main cap good. I had one not seat in the cap and bind up on me once but I noticed it cause the pump wouldn't tighten down correctly.

I have done this my self, only, i didn't notice that the pump wasn't tighting down correctly and also didn't pay any attention to the small snap sound that happen as the pump bolts were tighten.

Lucky i tried to prime my motor on the eng stand.
Couldn't get the priming hex in the pump Pulled it back down and ended up having to buy a pump.

 

[slippery440]

We took the pump out and suprise it turns just fine. I am not stupid so I put it back in finger tight and had Bucky ingage the pump prime stick and it turned easy. Then I tighten it down and the junk set up. Took it out and put the old pump in tighten down hard and worked great. I don't rebuild motors for a living but when I do I expect the parts to be machined right.Bucky is going to a local parts store and get a oil pump. The old one was bought from Indy Cly. So now we see how they treat him when he wants his money back. I want to say up frount it is not their fault at all that the Melling pump is junk. Its no wonder that it cost so much to have a motor built.

 

[1wild&crazyguy]

I had this happen on a 390 ford, the pump 'during priming' slowed and locked up.

poor clearance.

never happened before or after again.

I was surprised being that they've made a great pump for decades.

 

[moper]

I havent seen issues with the bore where the drive snout of the pump seats.. But if it worked lose, and didnt tight, I'd look there on the new pump for a shiney spot or something that wouldnt allow it to seat. Good luck on the refund. I'd bet they'd send you a new pump but they really don't like credits...lol.