Rebulding a K181 fuel pump

[AHS 1,411]

Ok, im rebuilding my Kohler 181 fuel pump. Im kinda lost! The right hand valve, in the fuel pump was out when i took it apart.  Those valves in the body of the fuel pump, are they in there right? What about the washer, does it go beneath the right one? 

[ebinmaine 63,218]

Did the washer come with the kit?

 

[AHS 1,411]

No, the washer fell out when the right valve fell out. I think it need to go in between the valve and the fuel pump half.. i think!

 

[rmaynard 14,911]

The check valves on that model should be a "press fit" into their respective cavities. The washer goes underneath each of them to further help to seal against leakage around  the valves. When you remove the valve that didn't fall out, you should find one under it as well. The fact that the one valve fell out indicates to me that it was loose and probably not sealing. If the new replacement check valves fit loose and don't need to be tapped in, I would use a small amount of silicone caulk on the perimeter of the valve to hold it in place. Be careful that you don't get the silicone anywhere near the little check valve disks. Allow 24 hours before completing the reassembly.

[Handy Don 10,640]

4 hours ago, rmaynard said:

small amount of silicone caulk

Fuel resistant!

 

When you go to put in the new diaphragm, it’ll seem like the holes don’t line up. That’s on purpose. You have to “scrunch” the diaphragm so that it’ll have slack so the center can move freely for the pumping action. Don’t worry about the edges “wrinkling” -- as you tighten the halves together the diaphragm flattens out.

 

Also very helpful to make sure the two pump halves’ mating surfaces are flat. Same reasoning and process as flattening a cylinder head.

[Gasaholic 183]

Naw, no silicone at all.  If the valves don't fit tightly (Looking at your last picture of the post, the top valve will be the outlet side of pump - It is possible to install them "wrong ways" on some , but not all - thus making the outlet the inlet and vice versa.) 

 

You put in the gasket, then the valve, and You can use a 12 point 14mm socket with the outside of the socket ground off to just fit the valve body recesses (14mm 12 point should clear the check valve retainer bits so socket is only pressing on the outer ring of the valve) and use that with a hammer to carefully drive them in securely - If the valves don't take some effort to drive them in they are likely loose, so once you have them fully seated, you take a center punch (sharp point) and on the little flats of the valve body on either side, you can hammer in a dimple using the punch, which pushes metal out to lock the valves in place somewhat (Referred to as Peening them in) that way you don't have any silicone, caulk, sealant, etc that can dissolve or come loose and stick under a valve disk causing them to hold open, thus defeating the purpose of check valve in the first place. 

 

 

[rmaynard 14,911]

18 hours ago, Handy Don said:

Fuel resistant!

While some silicones may not be fuel resistant, apparently some are. I repaired a fuel pump on an 857 (K181) back in 2012 using black RTV silicone to hold the check valve in place, and as of today, there has not been a problem. While the silicone is not being used to seal gas flow, it is only being used to form a bond to hold the valve in place.