How to prime a new oil pump

MGB Oil Pump

MGB High Flow Oil Pump

Don’t ever just install a new oil pump right out of the box. There are two easy methods of insuring the oil pump¬†will create the seal needed to pull oil in on initial start up. The first method is to pack the oil pump full of Vaseline. Vaseline will create the seal needed for vacuum to draw in oil. The Vaseline will then be quickly dissolved into the oil. The second method is to use engine assembly lube and lube all the moving parts. The goal here is to sufficiently coat all moving parts so when the pump spins for the first time vacuum is created to draw the oil into the pump and then push it through the system.



'How to prime a new oil pump' have 3 comments

  1. May 29, 2012 @ 6:01 am OleDoc

    My MG-TD has been sitting for several years. I drained the oil and when cranked no oil was being drawn up from the sump. Removed the plugs to reduce compression, still no oil. Removed the oil pump cover, no signs of wear, filled with oil, still not drawing. While I don’t relish removing that pump cover again, I’ll pack it full of vaseline and try again before dropping the pan.
    Thanks for the tip-


  2. February 8, 2013 @ 9:42 am Bill

    Are you suggesting opening the pump to lube the moving parts? I believe you are right about prelubing the pump and also the engine if this is the first start after a rebuild.

    Could you submerge the pump in motor oil, turn the pump shaft with a drill motor, perhaps in reverse and wait for it to pump oil, then install the oil pump. Also on V-8’s I have installed before the distributor goes in attach an electric drill to the drive shaft of the pump and spin the pump in reverse until oil pressure shows on the oil pressure gauge and check that oil is flowing to the valve train.

    Thank you,



  3. February 9, 2013 @ 2:10 pm Dave

    I have worked on MG’s since the early 1970’s. What I do is put some STP in the pump before I bolt it in. Before the first start, I remove the discharge line from the block and with a pump oil can, pump oil in the block until it’s full. With the spark plugs out I turn the engine over until the gauge shows pressure. It’s worked every time.


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