I have a Dodge Travco motorhome with. 440. It seems to have developed an oil leak somewhere around the oil pump. It looks like it could be the oil pump cover gasket or coming from the cap for the pressure relief ? It does not seem to be pump to block. I can't seem to find that gasket, only pump to block. Should I mess with the oil pump or replace it ?
If I replace it should I use a stock Napa one, a Melling HV or high pressure ?
It's in a motorhome. I used a Melling pump on a Ford years ago and it lacked pressure and cost me a set of bearing so not in love with them but that was a long time ago. Also motor runs pretty good overall but has 102k miles and she runs high RPMs on the highway being no overdrive and 4.56 gears,

IIRC there are two 'O'-rings that seal the cover to the body. A large one and a small one. The large one is available from almost anyone. I would think you could match the small one from an 'O'-ring assortment. Unless you have insufficient oil pressure, I can't see replacing the entire pump if a couple 'O'-rings will do the trick. I can't say this for sure but if you still have a burning desire to replace the pump, I think the only vendor left is Melling.

Try tightening the bolts first. As mentioned above, the cover uses o-rings. The relief plug uses a gasket. Personally my suspicions would be a) loose bolts b) oil filter gasket c) pump to block gasket. Other than the space shuttle, I've never known o-rings to fail.

I have, but at 5000 psi. And that is rare.

So, I'm with you, An o-ring is so over designed for this application, hard to imaging a failure there.

Hence my thought that it was the O-rings. Loose through bolting would guarantee a leak at the block gasket. We'll see.

O-rings sometimes like to fail with age as they are sometimes a bit "cooked". Anybody seen the oil filter adapter O-ring split on Chev 4.3 and v-8's? Or that distrib/oil pump drive O-ring on 2.8, 3.1, 3.4 chevs etc?

There are three O rings and a paper gasket.

Two O rings between the body and cover of the pump.

One O ring on the "snout" of the pump where it fits up in the block.

A paper gasket between the pump body and the block.

If the o ring on the snout fails, the paper gasket can only slow down the leak, it's not enough to stop it. And it is not a pressure leak, but a weeping kind of a deal. Usually it fails before the other two.

I would think that with 100,000 + miles on the motor home if your going to pull the pump to change gaskets and O-rings , I would just replace the pump with as stated above a Melling HV .

The two halves of the pump have virtually ZERO space between them. The chances of those rings failing is virtually nill. Likewise with the top o ring - very close fit and no pressure on it. My money's on a gasket leak. And a blown gasket would yield more than just a drip !! tighten the bolts, filter and pressure relief cap.

Take the pump off and take it apart, you should be able to determine where the leaks are
You don't say what year it is but I would bet money that it is at least 38 yrs old, I believe Mopar quit making the BB motor home chassis in the 1979 when they went bankrupt the first time
I have had the bypass valve plug, fitting, start to back out on new pumps on the dyno, they get warmed up and start seeping a tiny bit until I see it, I tighten them up and that stops it
Yours may be a gasket or o ring, let us know what you find out, maybe even a rocker arm cover gasket

Change the oil filter and make sure you don't have an old gasket sitting on there

What he said,pumps usually don't leak !

The part number for the pressure relief valve cap is FEL-PRO 3122,Mopar #618622

what Cab said, find the location first

Ok, thanks guys. The pressure relief cap was able to go another flat without gorilla force so maybe that will help but gonna clean it off again and scrutize it more.
If I have to pul the pump, anything I need know ? Anything gonna fall out ?
It looks pretty straight forward. Just take the longer bolts to block out and off it come correct ?

Once the bolts are loose and the oil filter is remove you MAY need to twist the pump a little to break the block to oil pump gasket free
Once it is out and you want to put it back in slide it up into the block and try twisting a little each way as it goes in to try and help it get the oil pump drive into the oil pump gear
Hopefuuly that chassis will allow you to drop the pump out without a hassle

If you go with a new pump, disassemble it, inspect and clean it before you install it.

You will be really annoyed if some machining debris jams up the rotors and it twists off the pump drive.

Kevin

You may need to pull the intergear to ease pulling it but see if the big block guys say that is needed or not. On a SB, on installing the pump I snug the 2 bolts lightly snug then drop in the intergear then torque the 2 bolts for dead on hex alignment. might be a good idea for a BB.

i have replaced bb pumps without pulling the gear.

Me too, a bunch of times, twice at the races

Ok thanks. There is plenty of room to work on it.