I have a presherwasher with th soap thing yep fill it with straight soap.
Also would allperpose cleaner take off hydronic oil off my tractor, if I put it in the washer?
Wilson, do you have a foam cannon or are you using the soap reservoir that is part of the pressure washer?
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The soap reservoir on a pressure washer does not work very well, as you need to have air added to make foam, which is what the MTM Foam Cannon does. The Adam's Foam Gun also adds air to the water/soap mix, but it can be used on a garden hose (no pressure washer required).
For your tractor, start with a pressure washer rinse, then spray full-strength All Purpose Cleaner on the oily areas and scrub with a brush, then rinse with the pressure washer.
Putting the APC in the pressure washer soap container or in a foam cannon would dilute it too much. On hydraulic oil, you need full-strength.
When using All Purpose Cleaner on paint, make sure the surfaces are not hot, work in the shade, and do not let it dry on the paint. Work small areas; rinse, scrub with APC, rinse, move to next section.