Kranzle pressure washer oil

[carbon]

Try polishing them with metal polish to see if the hard chrome is still there

The kranzle pistons have a thin ceramic coating that is in the wear zone so will definitely not look like a chrome finish

The pistons are discoloured, but i can neither see nor feel any other defects on them at all -

Discoloured isn’t a problem, if they were damaged you would see or feel it.

 

[julianf]

Got the water seal kit though the post just now. Will fit it later.

I reckon the oil seals must be a bit stuffed also, as, well, they were letting in the water (?) but they look quite a bit harder to change, so, whilst theyre cheap enough, i didnt order them this time.

Maybe if it leaks enough oil over the seals, it may make them easier to get out when i do come to doing them...

There is no sign of oil leakage currently, but, as i say, the oil seals are not keeping the residual water out of the oil, so i cant see how they can be perfect?

 

[carbon]

I reckon the oil seals must be a bit stuffed also, as, well, they were letting in the water

The oil seal is there to stop the oil leaving the pump past the moving piston. It is not there to stop the water entering the pump as the lip in the seal isn't working in the correct direction. As the drain holes were blocked initially the water couldn't drip out of the pump and the only way for it to go is in past the oil seal. I don't usually change the oil seals in pumps unless they are leaking oil past them. Some of the earlier kew machines had two oil seals fitted in opposing directions to try to stop water getting into the oil. I never saw the point in it as water still contaminated the oil eventually.
When I was at college one of the lectures was explaining oil seals on rotating shafts and the way he explained it was the oil seal can't make a perfect seal, there has to be some oil between the seal and the shaft to allow the movement between the two. If the seal is completely dry the spinning shaft with damage the seal when it rotates