pump oil

[mas3372 14]

Hey,

I am coming up on the 20 hours break in for my pump. I have a general 5.6 gpm, 3500 psi. I am curious on what oil to use. The manual says to use 30w non detergent. I got that. But is it needed to buy the more expensive general brand or is the cheaper stuff at napa O.K. Is 30W all the same.

Also, Just curious. I am away from my owners manual for a day or two because of my full time job. On average, how much do the pumps take, ie, 2 quartes, more?

Thanks, Mike

[Beth n Rod 1,279]

1 qt should do it for most pumps. It's capacity should also be listed in the manual.

Some people like synthetics over regular 30w.

Regular changes is the main thing to me.

Rod!~

[Russ Johnson 141]

30 ND is perfectly fine for all piston pumps.

[mas3372 14]

Thanks for the help. so for the most part, 30w nd is the same if it says general or cat or napa. It will be just as good?

Thanks.

[Wallydog 14]

1 qt should do it for most pumps. It's capacity should also be listed in the manual.

Some people like synthetics over regular 30w.

Regular changes is the main thing to me.

Rod!~

Rod, the 30 weight oil, is that the same as the oil you put in the sump of 4 stroke lawn mower engines? Or is it a more specialised oil. I emailed comet pumps and they said they now use tractor gear oil in all their pumps. that must be a generic oil you guys have but i don't know what weight that is? Over here in Oz a gear oil means 80w/90 or thereabouts and thats far to heavy for those pumps. Surely? Wallydog

[PLD 14]

30w non-detergent from your local auto parts place is fine. The only difference from lawn mower oil is the "detergent" part. Detergent oils are used where combustion by-products are present (like a lawn mower engine). Since there are no combustion by products, no detergent is neccessary. That said, could you use regular (detergent) oil? Probably, but since they specify non-detergent I can only assume there is a reason for doing so.

Also, since there are no combustion by-products in a pump, the oil change interval for the pump is many times that of the engine. My pump mechanic says that once a year is fine. I tend to do it about once a quarter.

Here in the US, "gear oil" is typically 90w as well.

[Doug T 19]

As it was explained to me..do NOT use detergent oil in a pump because of the foaming action.

[Wallydog 14]

As it was explained to me..do NOT use detergent oil in a pump because of the foaming action.

I have easy access to 40w non detergent oil used for my air compressor. Can buy it anywhere. Lots of compressors here. Does anyone have great concerns about using the 40w non detergent for the pressure washer pump as opposd to the recommended 30w non detergent. ? If the lawn mower oil is going to foam its not going to bond and lubricate very well. Sorry to harp on this but its important. The supplier of the machine said to use lawn mower oil and i had a feeling that was not going to do the job properly. Wallydog

[mas3372 14]

The way I look at is this. they say 30W non detergent, that is all i would Use. I question brand preference only because I suspected that perhaps manufactureres of pumps such as general may haver certain additives for just pumps. I would be hesitant to venture to a 40w or a detergent. Oil is cheap enough since they use such small amounts and so readily availabe at a local auto parts store that I think it would be foolish to use anything other than what is reccommended. Just my opinion.

[PLD 14]

As it was explained to me..do NOT use detergent oil in a pump because of the foaming action.

That's what I have always been told as well, but I have a real hard time believing it as I have NEVER seen detergent engine oil foam no matter how many gallons of water mixed in the crankcase.

As we are all aware, detergents and emulsifiers do not neccessarily foam by themselves. Despite our best attempts to "foam it up", it is often neccessary to add a foaming agent to get the desired level of foam.