What do they want washed on the forklift, and or why do they think they are dirty?
Forklifts generally are not very hard depending on the size, but this can also depend on what they want cleaned.
If the forklifts are gas/propane go easy around the plugs/cap as they will have a hard time starting it if soak them too good. Alternator, just don't stick the gun into the cooler and spray, gentle water or spraying over it should be fine, never had an issue with one.
Low pressure (1500-2000 PSI) , lots of heat to get the heavy grease/oil off. Degrease front lift pivots, engine, rear tie rods, radiator, and any grease you got on the cab and just rinse off with the same low pressure pressure heat. Avoid the chain at the front unless they want to grease the entire chain again, and make sure you take a good look in the engine bay and understand how clean they want them. Also when you wash the front lift points try to push the grease away from the cab unless you want to remove it twice.
If you are just taking off mud, pressure + water volume is your best friend. Don't go too crazy on the pressure, volume is your friend.
These can take 30 mins, they can take 2 hours, all depends on how detailed they want things. Throwing a number out I would say 45 mins to an hour first time, less after depending on how often you are cleaning them. Also depends on how muddy they get in between cleanings, how much they grease, and how bad the engines leak.
Take a good look when you are quoting and understand what they want, and what you can do. Maybe ask to try and clean one or all of them at a trail price and see how things go from there. Just say upfront that this is not your main field and you are willing to give it a shot and make sure both you and the customer are happy with the results.
If you have any more questions don't hesitate to ask.
