[nic holas woodman]

Wonder if anyone can help...

Basically i have a ninja with a pumptec 500 psi pump. When idle the pressure gauge sits no problem on 500psi but when the trigger is pulled the psi drops to around 220psi.  Wi first got the machine a couple of years ago the keyed pressure would be around 380 psi.  My machine has been like this for a while and i recently replaced the pump with a new one which at first seemed better( although not what it should be) but has now gone back to its old ways.

I have a guy who works on my machine and he cant work out what the problem could be.  It appears to be a lack of flow as when the trigger is pulled it takes a while to form a puddle

We have tried

-de -scaling
-the inline heater packed up and now that is by passed so no flow problem through there
- changed t jets
-checked filter in tank to ensure it's not blocked

The engineer says the flow dial seems to be working.

If anyone out there has any idea what the problem could be or what to try your input will be greatly appreciated

Thanks

Nick

[john martin]

i think i would check the regulator/uploader   ,   service it or just replace it . 

[Mike Halliday]

500psi  is trapped pressure created by the pump the 220psi is open pressure which is created by the restriction of the jets, (if you check the flow with an open solution line it will be even lower as there are no jets to restrict flow)

The pump specification will be a set psi at a set amount of flow, if it’s a 500psi pump then you are getting the correct psi now find out the flow per minute and test it ( use an open solution line firing into a bucket for 1 minute and measure how much water collects then compare that to the pump specifications )

It can be only 1 or more of 3 things,

Restriction going into the pump
Restriction coming out
Or a faulty pump

What are you testing the working psi with? a 3 jet wand? Try a single jet hand tool see how that effects the drop in psi

[nic holas woodman]

Thankyou for the responce.

The wand is a standard Ashby wand with twin jets fitted with 110150 . Also  the pressure on a single jet hand tool has the same drop.

Often in the space of a job the pressure/flow is inconsistanton with both handtool and wand with good pressure and flow one moment and a reduction the next. But like i previously said, no where near how i know it can perform.

Is the regulator/uploader the brass pressure valve or the black dial controlling flow or neither?

Thanks for your help

[john martin]

Yeah ,brass k nob is regulator , should be a YouTube video of talking the spring out etc. The flow valve should be a simple enough valve so I doubt it . It might be worth replacing the hose connector leaving the machine also ...would only take a chunk of black rubber from inside a hose to partially block it .

[AJB]

Check for air leaking into the pump feed, a pipe may be slightly loose. this needs
sorting out as it causes cavitation in the pump which is lots of small
explosions which can eat away at the pump. Also check for limescale etc
in the QDs but less likely to be this. also check the condition of the eccentric
cam bearing as this could be causing insufficient travel of the piston, hence low flow.
With twin 150 jets you should have no pressure drop when spraying.

[nic holas woodman]

Thanks for the great advice. Much appreciated

Can anyone recommend anyone in the Hertfordshire area that can carry out these checks

[nic holas woodman]

Hi AJB

You mentioned it could be air in the pump.

When the pump is running, if i turn down the flow rate with the black dial there is a hissing noise which sounds like air flow...Is this normal ?

Thanks

[AJB]

If the Ninja has an unloader as a means of pressure regulation then
you  will hear the diverted flow going back to the tank.
put an open pipe on the outlet and run the pump, or push a screwdriver
into the QD and press the centre in and listen for a change of note ie sound
from the pump. obviously do this outside