Bosch 1240 hammer/drill

[A.K. Boomer]

question about the type of oil used, what is it? parts cleaner won't clean it, drill works all the time but hammer only after warm, thinking it has to due with fluid viscosity,

was going to try adding a little lighter Bel-Ray full syn. fork oil to see if it helps but don't know if it's compatible and can't find any info on what the bosch oil is...

[JRouche]

If parts cleaner wont get it Im thinking silicone. JR

[A.K. Boomer]

That's what I thought too after i tried blending a drop with the fork oil, was like adding water to oil, so then i tried silicone spray --- same thing,,,

so then I tried reg. dot 3 brake fluid, bingo - blended and thinned it out... hmmm WTF is this stuff?

[A.K. Boomer]

added one tiny capfull of brake fluid to the mix and the hammer part is operable right off the bat instead of having to run unit for 5 minutes to heat up fluid,,,

should be good and at least hold the crew till we get some replacement fluid ordered...

[Willy]

I believe the oil used in your Bosch rotary hammer is an ISO 150 synthetic EP gear oil. Specifically Fuchs Renolin PGW 150.
The link below seems to be at a pretty decent price, I've seen the same product and size at over $52! Some guys are pretty proud of that stuff. LOL

https://www.texastooltraders.com/SDS...otary-Hammers/

I'm sure you could probably find a cross reference for it to another company's equivalent but seeing that it is an industrial product you'd probably have to buy a minimum of 5 gallons of it.
Okay I guess if you could sell it @$52/oz.

You might be able to source a small quantity from a power tool warranty facility. I'm lucky enough to have a local warranty outlet that will sell me small quantities of specialized power tool lubricants. It doesn't hurt to ask.

Don't think brake fluid makes a very good gear oil lubricant even though it makes the unit temporarily functional.

[A.K. Boomer]

Thanks Willy I ordered a couple fluid changes only 12 bucks a pop - also some piston and hammer seals I will be replacing so should be good,

very strange - would not expect syn. gear lubricant to repel other lubricants, and then mix easy with brake fluid so don't really know what the stuff is for sure... but will be nice to get it changed out for sure...