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Having a issue on HP soap - Seeing 2000+ PSI....

Car_Wash_Guy

Well-known member
Customer selects HP soap. Function works fine. When customer releases trigger, the PSI goes to over 2000 PSI @ the pump gauge. Pump bogs and can smell the belt slipping.

Bad unloader?

Thanks for any and all help.
 
Yup, change it right away. You also should have have a pressure relief valve on the pump. These are normally set to open around 1500 to 2000 psi to prevent the pump from exploding.
 
If nothing else changed, then yes it's likely the unloader. Howevever, I usually see that people attempt to fix a pump problem or check valve leaking, or regulator internally leaking by turning up the pressure relief. If the relief has been adjusted, then maybe the unloader is working just fine and shouldn't have been adjusted in the first place. You should set the pressure on the regulator when the weep gun trigger is released, not pulled.
 
If it was the unloader....Wouldn't it do the same on HP rinse too? I haven't checked all the functions to see if it's doing it on elsewhere...
 
I've seen it time and again where operator sees pressure a bit low, operator turns regulator up and doesn't see pressure increase, so operator keeps cranking it up until it's maxed, then leaves it like that. The problem was never the regulator, it was something wrong like a washed out tip, bad check valve, bad pump seals or o-rings, so the pump just can't achieve desired pressure. Then the trigger is released, suddenly the flow needed to the bay drops and the regulator being maxed out kicks in and pegs the gauge. You shouldn't have to set the pressure with the trigger released, but for f***'s sake if the pressure doesn't go up, stop turning it. I always set pressure with the trigger pulled, but if I'm trying to get 1200 PSI and it doesn't make it, I turn it back down until I see the needle drop a bit.
 
I've seen it time and again where operator sees pressure a bit low, operator turns regulator up and doesn't see pressure increase, so operator keeps cranking it up until it's maxed, then leaves it like that. The problem was never the regulator, it was something wrong like a washed out tip, bad check valve, bad pump seals or o-rings, so the pump just can't achieve desired pressure. Then the trigger is released, suddenly the flow needed to the bay drops and the regulator being maxed out kicks in and pegs the gauge. You shouldn't have to set the pressure with the trigger released, but for f***'s sake if the pressure doesn't go up, stop turning it. I always set pressure with the trigger pulled, but if I'm trying to get 1200 PSI and it doesn't make it, I turn it back down until I see the needle drop a bit.


Pulled the pump and found a bad seal. I think you were right as I'm pretty sure that I continually cranked up the regulator in an effort to keep PSI at 1400. Belt was loose too.

When the pump goes into bypass ( for example HP Rinse + trigger released) I'm seeing 1600PSI at the gauge. Is that normal.

Thanks for help. I owe ya beer at the show ( if you're coming)
 
You might still have the regulator set higher than the pump can achieve. With the trigger pulled, you should be able to squeeze the bypass hose closed, and if there's no flow through it that's just all the pressure it's going to make, so it won't hurt it to come up a little with the trigger released.
 
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