1973 Merc 500 h20 pump

[Chief847]

Hello I'm replacing or at least trying to replace the water pump on my 1973 Merc 500. I've got all the old parts out but I cant get the lower portion to pop into place on the new pump. I put grease on the lower O ring to help lube it up in an attempt to get it to pop into place, still no luck. Any idea on how to get the lower plastic piece to pop into place?

 

[merc850]

Do you have the drain or vent screw removed? The air has to escape to let the pump base go in.

 

[Chief847]

Nope I sure don't, either one Ill remove them both and try again.

 

[Chief847]

Well shoot all that did was get me excited lol. Still more then 1/4" away from seating in.

 

[Chief847]

From the looks of it I was sent the wrong kit. Looks like there is two kits almost identical. Both use the same top and internal parts but use different bases. I was sent 18-3324 and probably need 18-3323. The company I ordered the kit from said this was the kit I needed per my serial number. While trying to put the bottom base in I put gouges in the plastic since it wouldn't seat in.

 

[merc850]

There are two types of LU one has a "Flush" plug above the vent screw and one doesn't (newer), the "F" screw must be out to put the base in.