Flat top piston pumper maintenance

[Raden1943]

Hey guys I'm having some difficulty with my flat top piston 1322. I polished the tube of the gun really well and it's functioning ok but feels gritty and is scratching the top of the piston where the arm of the lever attaches. I'm thinking of taking it out and polishing the piston itself and replenishing the cylinder if needed. Two questions. First is this the best course of action. I'll take any better ideas you may have. Second what kind of grease/oil are you using? I have been using divers grease almost exclusively. I did put a small amount of silicone oil on the orings in the valve itself. My power and spread is good so that's what I meant by it being functional but I hate the feel of it. It's like nails on chalkboard. I forgot if it was an aluminum piston or steel. I think it's aluminum. If I can't figure this out I might have to get some stainless steel and get my lathe going but I would really rather not thanks dudes.

 

[Raden1943]

 

[Richely]

Second what kind of grease/oil are you? I have been using divers grease almost exclusively.

Not a 1322 owner so let’s get that out of the way. Silicone (divers’) grease does not provide lubrication for metal-to-metal contact. From your photo it looks like galling of the surface?

 

[Pale_Rider]

I use sae 30 non-detergent. Pumps smooth as silk

 

[Raden1943]

@legion So that's ok for the seals huh? That's why I used divers grease. Had a few products destroy my seals.

 

[nervoustrig]

I used 30W ND on my 1322 for almost 10 years. Had it apart a few months back and the pump cup looked and felt perfectly fine. I don’t know what material they mold the cup out of but it sure appears to be compatible with motor oil. Meanwhile most O-rings will be Buna-N which is also fine with motor oil.