Sprayer Pump Does Not Work With Engine On

[CCGATOR]

I use a JD 25 gal sprayer on my 825i, and have a problem where the sprayer pump cycles on and off every couple of seconds, only when the engine is running. It does not happen when the engine is off. I use it for spot spraying so it's not a problem except for my battery.

I know many of you have the larger spread sprayer (I assume also JD), and you must drive while you use it. Any pump surging with that pump. Or does anyone have the 25 gal sprayer and have that problem.. I don't know if it's the pump, the inability of the alternator to handle the 12 -14 amps, or what.

Can anyone provide any info on this?

Charlie

[GATORDONE]

How is the power lead hooked up.

[CCGATOR]

Directly to the battery with an in-line fuse. Switch in line, JD cable.

[BrodyJ29]

i have the 90 gallon does the same thing.

[CCGATOR]

Brodyj29, How long have you been using your sprayer, (approx hrs) with the pump cycling? My concern is also possible damage to the pump after long term use.

[BrodyJ29]

I have sprayed around a 1,000 gallons with it now. I am always moving with the motor on when using it. I know it does it with the wand but I also use the boom not sure that it does it with it.

[CCGATOR]

Thanks, my usage will be much less. I now feel that there is no risk if I continue to use it the way it is.

Charlie

[BarnDoor]

Most of those pumps have a pressure switch. When you initially turn the pump on, it will prime the hose/wand up to pressure and shut the pump off. The pump will not run again until you release the pressure by spraying the wand. So, if you hold the trigger it should run until you stop spraying.

[CCGATOR]

The pump does shut off when I release the trigger, as I would expect. If I hold the trigger down, the pump cycles on and off about every 1 - 2 seconds the entire time I am holding the trigger down.

[GATORDONE]

The pump is putting out more volumn then what the spray tip will handle that is why it surges like that. If you put in a larger tip then the pump will run longer. That is how they work with the demand pump.

[zionview]

Another suggestion is to plumb in a return line. The pump will run all the time and keep your herbicide mixed.

[825joe]

That is a good idea!

[zionview]

I put a plastic gate valve in the return line to help me regulate the pressure to the 4 nozzle boom(homemade sprayer). When I loaded the sprayer, I could open the gate valve, since the boom was closed, and get agitation with the full capacity of the pump. I don't have that sprayer anymore, but I used either a 4- or 5gpm ShurFlo. I put together a small manifold after the pump. Downstream was the outlet to the boom, return line and a pressure gauge.

[CCGATOR]

GATORDONE - That makes sense, I will allow more flow. But with all things being equal, why should it make a difference if the engine is running, or off with a set flow rate? Wouldn't the pressure be the same either way?

zionview - I agree with 825joe, you have a good idea. However I am not a farmer. I have a few acres and use the gator to keep it landscaped. You increased your flow rate to 4 - 5gpm. My tank only holds 25 gal. If nothing else works, I could perhaps do something similar on a lower scale.

[zionview]

CCGator- Just adding the return line with a gate valve should be enough.

[GATORDONE]

GATORDONE - That makes sense, I will allow more flow. But with all things being equal, why should it make a difference if the engine is running, or off with a set flow rate? Wouldn't the pressure be the same either way?

zionview - I agree with 825joe, you have a good idea. However I am not a farmer. I have a few acres and use the gator to keep it landscaped. You increased your flow rate to 4 - 5gpm. My tank only holds 25 gal. If nothing else works, I could perhaps do something similar on a lower scale.
With the motor shut off there is 12 volts going to the pump, with motor running there will be 13,-13.5 volts going to the pump because of the charging system which in turn will cause the pump to run faster and increase the flow which will cause the surging. I agree with zionview on installing a return line or you can also install a agitation line with gatevalve between pump and wand or boom which will increase flow.