SS pump losing pressure and pulsating

[platoridge]

I'm new is the Wash Industry I have two SS bays one TF Automatic and a IQ Soft touch. I just run it I don't own it! In one of my self serve bays when the pump is at "Idle" the pressure is 1200 psi but, when the trigger is pulled it drops to 725 psi and pulsates. I can't find if it is sucking in air. I changed out the belt because it appeared to be too loose but that didn't help.
The only other thing I thought would be the pump head. Does any one have any other suggestions?
Thank's!

 

[DiamondWash]

Some things to check:

1. Hi and Low Pressure Seals
2. Pressure Regulator
3. Worn Nozzle
4. Wand gun in the bay
5. Pump head could have washout issue

 

[I.B. Washincars]

I would first determine if it is cavitating or not. Hook a reliable water supply (garden hose or direct hookup to gravity tank) right to the pump inlet and then run it. If it smooths out you most likely have a cavitation issue. If not, start ruling out the other suggestions.

 

[PaulLovesJamie]

I'm betting valves. Partly because they cause exactly the problem you're describing, and partly because they are the quickest and easiest to check (& fix). Could be any of the things mentioned above though.

 

[JIMT]

What you have described is the spray nozzle is worn out or too big or there could be a leak in the high pressure hose.
The first thing I would try is putting in a new spray nozzle on the trigger gun.

 

[Kevin James]

It would be helpful if we knew what kind of pump your using? and how old it is, etc. It could be a number of things, seals, valves or head wash out.