Melling M-15 oil pump.
 

Anyone have one of these they could check to see how free the gear turns? Friend has a new one never used but has sit for 10 years or so and is very stiff to turn.Just curious if that is the nature of it with a stiff spring or something is binding it up. I believe this is made from the big Lincoln engine oil pumps? Thank You.

Re: Melling M-15 oil pump.
 

I have two of them, one new and one used. They both feel the same to turn by hand. If yours is stiff it may have crusted up assembly oil in it. Pop the cover off and take a look.

Re: Melling M-15 oil pump.
 

Thanks,that must have been it although didn't look like it but it freed up and spins now.

Re: Melling M-15 oil pump.
 

I don't recommend the M15 pump for street engine, they have longer gears and to much oil pressure, the M19 has plenty of pressure. the M15 is made for race engines with extra bearing clearance . The M15 would help a worn out engine. Walt

Re: Melling M-15 oil pump.
 

As the Flathead King pointed out, the M15 is not the best choice because all that extra pressure that is not needed builds heat, the enemy of the engine and the lube oil.