The search function on this site will yield some good conversations regarding the different Y oil pump designs.  Some key words to use would be gerorotor, gerotor, spur gear, rotor, gear oil pump, etc.

Lorena, Texas (South of Waco)

If I am reading your post, right you have installed a new pump and now it will not build pressure?  If that is the case then there are a couple things you need to do and this is based on very recent experience starting a newly rebuilt motor.  The new and clean pumps do not seal well enough to pull enough vacuum at low cranking speeds to pull the oil up out of the pan. So...

-First take the plate off the oil pump and smear a little grease in it. You need to work it into the entire pumping surface. 

- Second Fill the oil filter with fresh clean oil.  this is pretty easy if it is a spin on type not so easy if it is the old canister type

-third  put a 1/4" pipe to hose fitting into the oil gallery of the engine. you can remove the pressure sender switch to do this.  Put a piece of rubber fuel tubing  and a funnel on the fitting.  Pour oil into the funnel and let it run into the engine.  It wont flow very fast once it fills the oil gallery.  It will take about a cup or 2 of oil before you get tired of waiting for it to drain into the motor. Once you get about a pint of oil into the gallery you remove the fitting and replace the sender switch or what ever. 

-fourth crank the engine without the spark plugs in it. It will spin much faster. You should build oil pressure pretty quickly like 10 or 15 sec and you know that you are not hurting anything because the bearings are lubed via step 3.

A pre oiler as described in earlier posts with an electric drill motor to turn the pump will usually work also because it is spinning faster. It will work even better if you put a little grease in the pump.

Doug T

The Highlands, Louisville, Ky.

Have you tried turning the oil pump shaft with the distributor out? I think a 1/4" deepwall socket and long extension will do it. I use a cordless drill for mine. Make sure you turn the same direction as the distributor. If the oil pressure comes up then you need to pull the pump and check the oil pump rod for damage or length. I understand there are two lengths of rods out there and a short one in the wrong place dosen't work. Chuck in NH

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

John: You say the Melling's pump won' t bolt up? I'm not familiar with that model number, but if it's a Ford/Merc Y pump, it should fit. So ?. If you have a complete lack of pressure, whether or not to use a Gear or Roter style pump is not really relevant. Something else is wrong with your engine. Along with the other checks already mentioned, could the bottom of the distributor drive or drive rod be stripped? Also, do not run the engine until you are fairly certain you have solved the problem, or you will have more headaches to deal with..

Paul

Here's a new Elgin brand oil pump on Ebay right now.  $51.95 with free shipping!

Ebay oil pump 

A.J.

South Jersey

SMSgt USAF Retired 
1955 Ford Ranch Wagon & a couple of old guitars...Life's Good!

Hi, sounds like you have checked most things, have you rechecked the rubber seal on the pickup tube behind the large oil pump nut, it could be sucking air and not allowing oil to be picked up by pump? Good luck, regards aussiebill.

  AussieBill            YYYY    Forever Y Block     YYYY

 Down Under, Australia

If your engine has lots of miles behind it, worn crank bearings could be the reason or damaged center camshaft bearing. Too much play in bearings and it can´t build pressure. I have had these problems in couple of engines, in y-blocks and small block fords. I have now here one y-block which crank is going to machine shop for just that same reason. In that crank the tolerances is just in outer limit with main and connecting rod bearings, but it don´t build enough pressure to get oil to heads and oil pressure gauge says nothing.

Tero from Nurmijarvi, Finland

56 Country Sedan, 61 F-100, 61 F-600, 55 F-620, 52 Mercury

http://www.dlc.fi/~teros

http://www.y-block.info

http://www.hollowheads.net

http://www.fordnationals.net

I was checking pressure with a gauge and could see a small amount of oil coming up the hose but it never made it past the fire wall, also ran the engine with the valve covers off and could not see anything there. I replaced the oil inlet tube because it was damaged while putting in the engine. I did also buy a new hex drive shaft for it to be on the safe side.

What about the sealed power pump part #22441123?

What I did on my engine I took out the distributor and I put a long quarter inch extension with a socket in the distributor hole and turned the extension counter clock wise with a electric drill and I was able to pressurize the system before I started the rebuilt engine. Maybe your hole in your  distributor shaft is worn and it can't spin the pump shaft

As for as I know the Melling gear pump is the only one that is available now. Precision Pumps offers a blueprinted pump that shows up on ebay occasionally. Rebuild kits are still out there for the rotor pump, but are hard too find. As stated above if you are turning the pump by hand or with a drill, remember it rotates counter clockwise. If you are running the engine, it sounds like a drive problem.

Glen Henderson



Freedom is not Free

Letohatchee, AL