unloader problem?

P

Pressure Washing Sidewalks

New member
Having trouble. Sometimes when i press trigger there is a delay before i see the water come out. Other times while washing the hose will start to vibrate and i will lose pressure. When this condition occures i release the trigger and wait for the pressure to catch up (so to speak) some times i have to do this a couple of times before it will operate properly. When this first started happening i thought there might be some dirt in the system somewhere. Yesterday while the trigger was off and i was brushing the motor just about stalled , just before it completly shut off it would catch itself (so to speak) and run back up to normal rpm this cycle would continue every 2 min. Took the washer to the dealer he said he ran it for a 1/2 hour and it worked fine. Makes me wonder if he even looked at it! Today while on the job the stalling sitiuation stopped but while the machine was running you could here it pop and miss through the exhaust. WHAT THE HELL IS GOING ON WITH THIS THING! All these problems seemed to started at around the same time. The machine is a mi-ti-m 3505 4.7 3500, hot water, briggs, 21 hp pressure unloader yu240. I am not positive on that part # dealer gave that to me. It has a big green spring on it. The machine has 90 hrs on it . Also by accident today (i thought the watts valve was open) i started the machine with the valve closed when i 1st bought the machine i did that and the machine stoped turning over before it started because the valve was closed. I hope all these problems are unloader related. SORRY for the long post wiz, just been one of those days!
 
First off you need to pull the trigger whenever you start the machine. Keep it pulled until the machine starts. That small starter can not handle 3000+psi. I have seen so many starters fry from that. Second it sounds like your pump is cavitating from low water flow at the pump inlet. This is caused by Kinked hoses, loose Clamps, Dirty inlet filters, stuck valves, open soap valves, ect ,ect. As for the engine sputtering check the air filter out and see if it is plugged up with dust or oil. Also check out the oil, these engines usually have an oil pressure sensor that shuts off the engine when it is getting low on oil. Just had an engine blow up the other day because the oil sensor wire was off and the oil was drained out of the engine. That customer failed to notice why the engine was shutting down and pulled the wire off to finnish the job and now he is out of business until he gets a new engine.
 
Can a faulty unloader put pressure on the motor and cause it to not run rite . 250gallon water tank supply filter is clean, motor filled with oil.
 
Yes especially if it is set too high or if something is stuck in it. when you release the trigger there should be only about one second before the unloader releases the pressure. If you have a guage there should only be about 400 psi jump in pressure before it unloads. It is also a good idea to run the bypass into the tank instead of back into your pump. Just run the bypass into the tank and plug the port it was going into the pump with.
 
Thanks for the info wiz. If you plum it that way and you are upsreaming soap can it go back in to supply tank?
 
It depends where your suction is created. You could end up with all of the soap in the big tank. If you have soap going into the pump inlet it will continue to run unless you shut it off with a ball valve. But if it is after the unloader it will shut off when ever you release the trigger. You can not use the downstream on the high pressure side an upstream must be used. To control it just lower the pressure with a soap nozzle or a dual-lance wand.
 
You must log in or register to reply here.
Back
Top