Hardi sprayer loosing a bit of pressure

[dannewhouse]

I set sprayer to 3 bar 500 PTO revs 10kph
Set off with say 1000 litres.
As I get down to say about 500 I start having to up the pressure a bit every run to keep 3 bar.
(Not just the start until gets to full pressure in first few yard) but if left untouched it will spray the length of field at say 2.95 bar.

It's an older 1200l 21m mounted
I'm sure it never used to do it.
When I go with next tank I have to drop pressure loads to get back to 3bar

 

[quattro]

Has it got suction filter in top of tank?
if so it could be sucking air in there through o ring or sucking air somewhere else
has it got a clean water tank?

 

[dannewhouse]

No clean water tank.
Yes suction filter, would you expect it to start as tank gets lower though or are you thinking it starts as suction vaccum increases?

 

[davidroberts30]

either air ingress or dodgy valve but if it was a valve it would fluctuate

 

[Allsorts]

My Hardi does the same when it gets down to the last 200 litres, just jump off and turn off the recirculation valve (top one).

 

[dannewhouse]

My Hardi does the same when it gets down to the last 200 litres, just jump off and turn off the recirculation valve (top one).

Al take a pic later but I just press the + switch in cab to up pressure back to where it was

 

[balerman]

It is definitely a suction problem somewhere,most likely the o ring under the red filter cover,or a split or hole in the long pipe in the tank it sucks through.

 

[colhonk]

Had mine for 28 years and it has always done the same, just need to press the + swich to up it a bit, then - to start a new load. Used to try to solve it but just live the happy life now and ignore it. even when I put a new pump on it was exactly the same. Tried all the above but no different.

 

[Dave W]

No clean water tank.
Yes suction filter, would you expect it to start as tank gets lower though or are you thinking it starts as suction vaccum increases?

Suction fitting at the top definitely first place to look. As water level drops it's harder for it to suck up. The seal inside the lid will likely have failed or filter not clean

 

[spin cycle]

does you hardi have the little diaphragms on the pump held on by jubilee clips?......that did for my pressure once... day after mot

 

[dannewhouse]

No 6 diaphragm pump, looks like this one.

 

[KennyO]

Ours has a bit of flexible hose joining the hard suction pipe together. Had jubilee clips fail there.

Ours does the same. Again just live with it.