[drive surgeon]

does anyone know any symptoms of a faulty unlaoder valve.?

when my machine is in by pass mode instead of a constant engine rev noise every 4 seconds the engine makes like a loud high rev noise then goes back to normal revs. when this happens the pressure gauge jumps up also.  could this be a faulty unloader valve like merril fox suggested or more likely to be the crank shaft worn like my service engineer says?

[BDCS]

It sounds like Beryl is right, take out the return hose and if the flow stops when it revs up then its the unloader. I doubt if you'd get any drive if the key has sheared.

[drive surgeon]

thanks bdcs

[drivewasher]

If you have any slight leaks on high pressure hose conections or if there is a "leak past" the trigger gun when in lay down then thats the problem it needs fixing as it will wear the underloader out. If underloader is causing this, symptom usually is a trickle of water from under the adjuster numpty around the shaft, if thats the case then the underloadr is knackered. Thats usually caused by the former faults not being rectified as they occur

[drive surgeon]

i haver noticed steve that when i pull start the engine up on low revs water leaks from where the hose goes into female connector on machine. that never used to happen, its a new female connector too.  so is it the unloader or connector?

[drivewasher]

Any leak on the high pressure hose or fittings needs to be sorted asap. This will make your engine "surge" when the underloader drops back in to replace the lost pressure in the trapped line.

[drive surgeon]

machine keeps cutting out now too?  surely the unloader cant make the machine engine cut out?

[Kleen Machine]

Check to see if the thermal relief valve is blown. You will see a constant
drip coming out of it. This can be causing your problem. If it is blown
you have to install a new one.

[drivewasher]

Check to see if the thermal relief valve is blown. You will see a constant
drip coming out of it. This can be causing your problem. If it is blown
you have to install a new one.

His machine bypasses to tank so it won't have an overheat protector in it. His hp hoses have leaks on them

However the engine cutting out is another issue, we'll get the full story eventually, it's like pulling teeth lol...

[stalwart]

Wisdom teeth 

[drive surgeon]

im putting it in to get looked at.  :  there is something going wrong every week 

[drive surgeon]

unloader valve has gone they said and it was caused by a dripping outlet from pump.

its gonna cost me a few bob this 

[BDCS]

I change the unloader every year

[drive surgeon]

why every year? and how much do you pay/  does your unloader have a "by pass" to tank female outlet on?

[BDCS]

I change it because they are about shot by the end of the year, I don't want to be messing about with the machine when I need to be cleaning and a weep back to tank can cost you hours in cleaning time. They are about £30, I service my own kit so what I save on paying some half wit at a plant shop I can spend on the kit. The unloader is an external by pass ie seperate return to tank, nobody in their right mind would buy anything else for professional use - how can you use your washer with hot water if its got a thermal cut out ?

[drive surgeon]

its a cold washer.  my engine was a bit low on oil so that may be why it cut out.  not sure yet.