yanmar 2gm20f fuel lift pump gasket question

[lk240]

Hello all,

I'm working on solving a fuel leak on my yanmar 2gm20f and I'm replacing the fuel lift pump. I've got the fuel leak fixed but now I'm having difficulty getting the gasket on the fuel lift pump to set properly and I'm having some oil leak now. the gasket I received with the fuel lift pump is the second one pictured below and it appears quite smaller than what appears to be the yanmar gasket and I'm wondering if others have run into this issue or used the smaller one without problem? If so, any tricks on getting the gasket to set right aside from using a bit of permatex 2 on the pump side?

thanks for any input.

Lisle

[lk240]

Here is a picture not pdf'd.

[Compass790]

Pretty sure you have the wrong gasket in the photo but dont worry as you can just use silicone & no gasket or Loctite 518.
Our Yanmar ysm8 has the same pump body & its gasket was the one in the PDF but I just use silicone . You put an even layer of silicone on the pump sealing face & let it go off overnite before bolting the pump on. If you want to use immediately use Loctite 518.The Permatex may work as well but I'm not familiar with it.

Guess it was an aftermarket pump?

[lk240]

Thanks! Yes aftermarket. Appreciate your reply. Lisle

[tkeithlu]

You got a good response from Compass790, but I feel like adding two general comments.

Compass 790 mentions something lots of people miss, which is often expressed as put on the goo, position the part, wait for the goo to set, then torque it. If you torque while the stuff is wet you get no compression and very limited ability to seal.

The second is that you can save yourself a lot of trouble in these situations by getting some gasket paper and making your own. You place the paper over the part to be gasketed, and then cut it by tapping with the rounded end of a ball-peen hammer for the curved edges. With just a bit of practice you can turn out a gasket in a few minutes. Having several thicknesses of paper lets you choose a thicker gasket that will seal easily in these low pressure situations.

Good luck with it.

[lk240]

Very helpful, Thank you!

[Compass790]

Good addition tkeithlu.
I forgot to add its safer to put threadlocker on the bolts as well if your motor vibrates much.
So what did you do Lisle & did you fix your leak?

[lk240]

I’m awaiting new gasket and copper crush washers arriving tomorrow for the fuel line and going to have another go at it Friday, will post update thanks so much.

[lk240]

By way of update, I think I finally got it fixed!! It seems something was awry with the aftermarket fuel pump such that even after using a yanmar gasket, it was still leaking oil. So to test this I put the old pump back on and sure enough - no oil leak - but still diesel leak. Ordered a new yanmar fuel pump and installed this morning and thankfully no fuel or oil leaks!! Thanks again for the replies. Lisle

[Compass790]

Glad you solved it & hope you get a refund on the faulty pump.