no high pressure

[Jimmy Buffett]

I have a Jim Coleman pump bench. Someone broke a wand in 1 of the bays last night which is not unusual. When we fixed the wand we did not have any high pressure function. Low pressure is fine The JC bench uses the same pump for both low and high pressure. We assumed that it was the gun so dad changed that but no change. We have tried every gun we have and that doesn't help. Any idea what I should be looking for?
Thanks
J

 

[MEP001]

Did you check it on soap and rinse? If it has pressure on rinse only, you could have a bad inlet check valve, which may be located on the plumbing under the tank. If neither, make sure the pump is running when a high-pressure function is selected.

A customer may have broken the gun because there was no pressure before; don't assume it's the gun.

 

[Jimmy Buffett]

I just have low pressure only on both high pressure functions. The pump sounds fine but is just putting out 400 lbs of pressure. I can't tell that anything is happening at all when the handle is squeezed. I'm hear by myself so I can't squeeze and listen at the same time. The high pressure functions operate on low pressure until the trigger is squeezed. Would there be some sort of breaker that only serves the high pressure function?
Thanks

 

[randy64]

Try running the HP function without the nozzle on the gun

 

[PaulLovesJamie]

I'm hear by myself so I can't squeeze and listen at the same time.

Sure you can ... duct tape!

 

[Greg Pack]

Jimmy, sounds like your medium pressure solenoid may be stuck open. It's the solenoid to the left of the pump. When it is open, the regulator behind it takes over and reduces pressure to 400lbs. Try increasing the pressure on the regulator by tightening the nut. If pressure increases that would confirm your solenoid is stuck open. It's a dema solenoid , so just bang on it! Hope this helps, email me if you have further questions.

 

[Jimmy Buffett]

Jimmy, sounds like your medium pressure solenoid may be stuck open. It's the solenoid to the left of the pump. When it is open, the regulator behind it takes over and reduces pressure to 400lbs. Try increasing the pressure on the regulator by tightening the nut. If pressure increases that would confirm your solenoid is stuck open. It's a dema solenoid , so just bang on it! Hope this helps, email me if you have further questions.

The solenoid does sound like mthe problem. I had dad remove the wand to make sure there was not a problem with it and there was not. I think I will wait till I get home from work to bang on the solenoid though. I never tell my dad to hit things with a hammer!
Thanks guys. I'll let you know this afternoon.

 

[JMMUSTANG]

Most likely the solenoid but I have had several hoses from k.r. that had the swivel ends put on by them that were crushed at the end of the hose thereby getting little to no pressure.
Might check that out too.

 

[Jimmy Buffett]

Jimmy, sounds like your medium pressure solenoid may be stuck open. It's the solenoid to the left of the pump. When it is open, the regulator behind it takes over and reduces pressure to 400lbs. Try increasing the pressure on the regulator by tightening the nut. If pressure increases that would confirm your solenoid is stuck open. It's a dema solenoid , so just bang on it! Hope this helps, email me if you have further questions.

The pressure does go up when I turn the nut. It is registering 1200 lbs at the guage but only getting about 400 at the bay. I banged on the solenoid (I think) some but to no avail. Should I just keep banging on it? Just smack it under the coil?

 

[MikeV]

Yeah, that's what I tell my customers when something like a coin acceptor is jammed or won't accept a coin..hit it harder!!! .....NOT!!!! Dude, please don't come to my carwash and try to fix anything.
I don't recall fixing anything by hitting it . If it is the solenoid, you need to take it apart and fix it, or replace it.

 

[car washing systems inc]

have you checked your tip in the bay it could be cloged?

 

[Jeff_L]

You have 1200psi at the output of the pump and 400psi at the output of the wand? How do you know you have 400psi there? If that's true, then you have pressure loss somewhere between your 1200psi location and the end of the wand. I would start at the pump side and start taking apart your connections to see if there is some blockage downstream of the pump restricting the water. Could be a pump part or buildup inside the line which broke free and is now jamed against something in the line.

Another thought is that you may have a check valve open somewhere in the lines allowing the high pressure water to go back through them to somewhere else?

Are you sure there is no water spraying/leaking anywhere?

 

[Jimmy Buffett]

You have 1200psi at the output of the pump and 400psi at the output of the wand? How do you know you have 400psi there? If that's true, then you have pressure loss somewhere between your 1200psi location and the end of the wand. I would start at the pump side and start taking apart your connections to see if there is some blockage downstream of the pump restricting the water. Could be a pump part or buildup inside the line which broke free and is now jamed against something in the line.

Another thought is that you may have a check valve open somewhere in the lines allowing the high pressure water to go back through them to somewhere else?

Are you sure there is no water spraying/leaking anywhere?

Actually I only thought that I had 400 lbs. That is normal low pressure function. You could not feel any difference when you pulled the trigger. When I put on my glasses and realized that it was actually reading 1200 at the gauge I felt like an idiot. It did turn out to be a tiny obstuction in the tip. It seems to me that an obstuction at the tip should RAISE the pressure instead of lower it since there is more water trying to get out of a smaller area, but obviously that is not so. More times than not the solution turns out to be simpler than the one I'm looking for. You would think that I would learn!
Thanks for all of your help!

 

[Greg Pack]

Yeah, that's what I tell my customers when something like a coin acceptor is jammed or won't accept a coin..hit it harder!!! .....NOT!!!! Dude, please don't come to my carwash and try to fix anything.
I don't recall fixing anything by hitting it . If it is the solenoid, you need to take it apart and fix it, or replace it.

I'm trying to troubleshoot the problem online, not standing there charging XXX to fix it. Dema's are notoriously bad for sticking open, and hitting it will usually close it, at least temporarily. Right or wrong, I've done it many times.....

Jimmy, if you monkeyed with it make sure that you adjust the medium pressure regulator back to the proper pressure.

 

[I.B. Washincars]

I agree with cfcw. I've rapped a few Demas and got them to close. Was it a permanent fix? Probably no, but it nails down the problem in the blink of an eye...or maybe the whack of a hammer.

 

[Jeff_L]

I thought DEMAs came with a free hammer just for this purpose?

 

[randy64]

More times than not the solution turns out to be simpler than the one I'm looking for. You would think that I would learn!
Thanks for all of your help![/QUOTE]

Occam's Razor

 

[MikeV]

I'm trying to troubleshoot the problem online, not standing there charging XXX to fix it. Dema's are notoriously bad for sticking open, and hitting it will usually close it, at least temporarily. Right or wrong, I've done it many times.....

Jimmy, if you monkeyed with it make sure that you adjust the medium pressure regulator back to the proper pressure.

I understand, but that's not really fixing the problem, just the symptom. I am also familiar with the Dema valves and I do know that a tap here and there will temporarily take care of it, but unless you fix it right, it will stick again....usually on a Saturday afternoon while you're out golfing.

 

[Jimmy Buffett]

Who (in thecar wash business) gets to golf on Saturday afternoon?

 

[MEP001]

I understand, but that's not really fixing the problem, just the symptom. I am also familiar with the Dema valves and I do know that a tap here and there will temporarily take care of it, but unless you fix it right, it will stick again....usually on a Saturday afternoon while you're out golfing.

No one ever suggested that it was a permanent fix. As cfcw already said once, he/we are only trying to diagnose the problem.