I have this Sears Craftsman Pressure Washer 900 (so it sez on the label); electric, 12A. The gauge goes to 2000psi, the label says 900 psi, but it feels like a regular garden hose when it’s on.
Is there a washer or something that I can replace in this thing? Its very heavy and the motor still runs, so it seems a shame to ditch it. OTOH, it’s 10 years old and I got it free, so if nothing else I can tear it apart for fun. 
Hmmm, hard to say without more details. I wouldn’t think it’s a washer. Is water leaking from the inside somewhere, do you hear air escaping from the inside? I guess what I’m thinking is one of two things. Either, the pressure is being diverted somewhere else (which may be found by listning/looking for air or water leaks, but I’m gussing if that’s the case the pressure is escaping before it pressurizes the water, so take the case off and make sure everything, all the bolts, fittings, caps etc are nice and tight, and if you feel safe running it without the cover take a look/listen for any leaks that don’t seem right) OR the motor isn’t doing anything (probably more likely). If it’s belt driven make sure the belt is in tact, attached to the proper pulleys, and spining them. If the belt is spinning, but the pulley (not the one on the motor) is NOT spinning (in which case you’d probably smell burning rubber) the insides (pistons?) have probably ceased, you MAY be able to hand crank it once or twice to get it started, I’m not sure. If it’s not belt driven you may have similar problems but broken gears instead of a belt. There’s still quite a bit more things to look at, but if I were diagnosing it, I would take the cover off, start it up and make sure everything looks, sounds, smells ok. It maybe something very obvious (like a broken belt).
I think you’re right about it escaping before being pressurized.
It’s much smaller than you probably think. (More like this thing, basically this with a plastic case. It’s all in-line with the main armature; I stopped taking the back off when I realized it housed the motor, :smack: and since it seemed to turn ok I didn’t wanna break it.
So I took the front off; there’s a bit of magic that turns the rotating armature into an in/out action for three pistons arranged in a triangle, that go in & out about 1/2". The seals around those looked ok, but (after taking more of it apart), there are three 1-way valves made out of plastic that look and feel shot to me. They’re held in by three metal rings that probably pop off or screw out (I hope).
Craftsman seem to have replacement O-rings, but not valves, so I may be hooped. OTOH, their website doesn’t show any electric washers either, so perhaps its just not listed. Mayhaps a personal visit is in order.
You might try soaking the check-valves in vinegar. It doesn’t take much mineral buildup to make them fail.
Go here http://www3.sears.com/ for Sears and other Parts. They will have breakdown’s, parts lists and a venue for ordering parts.
The valves look like they’re actually chipped around the edges. I phoned Sears, and it seems they don’t buy into planned obsolecence, and might actually have the part.
Working with this kind of stuff is fun; you do so little of it around computers. 
Ahem - to those unfamiliar with the operation of the above mentioned type of device, before you take off the intake valve, remove the piston plate, unscrew all pressure bypass fittings, disassemble the main pressure chamber, tease out all O-rings and pop out the check valves, you should take a look at the sprayer itself, 'cause some brands have an adjustable nozzle and if it’s set in non-pressure mode it’ll feel like a garden hose.
:smack:
That is all.
