1948 chief oil pump is not returning

[jn1972]

I went to take my 48 chief for a ride today ,started and checked oil before leaving oil is not returning to the tank is there any way to check with pump on motor or do I have to pull pump off thanks jerry

[tfburke3]

Unless the scren on the sump is plugged or or sucking air with a loose fitting,the most likely thing I thinkis a sheared key in the pump.They are really small.Is oil building up in the sump?Do you have the ball valveinstalled?Sometimes they stick.
Tom

[jn1972]

The oil level is staying the same in the tank so I do not think it is going into the sump,I have the check valve installed I will check that ,also I have a Greer spin on oil filter installed but I do not think that would matter thanks jerry

[pisten-bully]

Gerald, first ride this year, or did this problem crop up after riding it a few times? And have you had that spin on filter for a while with no problems before?

[jn1972]

I have been riding for at least a month ,I installed the filter after the motor was rebuilt last year ,the problem just started today ,

[pisten-bully]

I have been riding for at least a month ,I installed the filter after the motor was rebuilt last year ,the problem just started today ,

...that shoots my theory

[PaulCDF]

After your ride was the oil in the tank hot?
No visible return of oil out the tank return tube?
Did you find the sump full when you removed the lower crankcase drain plug?

[jn1972]

I removed the pump ,put on an intake line and spun the pump with a drill it pumps oil fine ,I do have some cracks in the aluminum where the top fitting goes in maybe sucking air there ? I guess maybe time to replace pump ,has anyone had experience with either greers or kiwis pump thanks jerry

[Jim]

I removed the pump ,put on an intake line and spun the pump with a drill it pumps oil fine ,I do have some cracks in the aluminum where the top fitting goes in maybe sucking air there ? I guess maybe time to replace pump ,has anyone had experience with either greers or kiwis pump thanks jerry

Before you buy a pump, why not try a bit of JB Weld on the cracks first? That would at least eliminate that as a suspect area.

[tfburke3]

If the top fitting is cracked,the return line,thats on the discharge side of the pump so worst case would be oil leaking out.
The sucking air is from crankcase to the return pump,but sounds like you are getting no supply.If the supply fitting leaked it would leak while sitting.
Also the pump only spins 1/2 engine rpm so your drill test may have been faster than when warming up,and possibly unstuck the ball valve.
I get return flow from just kicking bike over,but I dont use the ball valve which is another conversation you are probably familiar with.
You test set up should show flow ,level drop in line,spinning by hand.
Tom

[jn1972]

I will give spinning the pump by hand a try ,is it possible for the pump to get air bound some how ,I know on my old 741 sometimes I would have to use my oil can and pump down the discharge line to get oil pumping ,I tried that on the 48 chief but it did not work thanks jerry

[tfburke3]

I will give spinning the pump by hand a try ,is it possible for the pump to get air bound some how ,I know on my old 741 sometimes I would have to use my oil can and pump down the discharge line to get oil pumping ,I tried that on the 48 chief but it did not work thanks jerry

He JerryIf you spin by hand you dont even need the line.Just fill to the top of fitting a turn of the pump should suck it in.
The priming the pump discharge line or return tube primes the return pump.I think you eliminated that when you said the oil tank level wanst dropping,and I guess no build up in the cases.So you are working on the supply pump.Its 2 pumps in one housing.
Personally I would remove the pump gear cover and inspect the gears and housing,then put it back together if things look good without the ball valve and spring and see if it pumps.
The only way the gears dont get oil feed is if the pump doesnt create enough suction to pull the ball off its seat.
Tom

[jn1972]

My son was able to mill out the body of the pump and retap to get rid of the cracks near the return line ,I disassembled the pump and removed the ball and spring,put it all back together and it seems to pump fine ,not sure what was wrong ,thanks for everyone’s help jerry