Need help with a sprayer

[coosa]

Jeff- There is no problem with the pto speed. I'm using a John Deere 5210 (by far the finest machine of any kind that I've ever owned) and I keep it well above the minimum pto speed. I'm not sure how many rollers the pump has; I'll check this weekend.

Thanks for all of the good ideas from everyone. I'm planning to go back to the farm this weekend and I will look into everything that has been mentioned. I'll post what I find out.

Steve

 

[RAB__AR]

The next time you use it and the pressure drops check the suction hose between the pump intake and the tank to see if it is collapsing or sucking flat. As the water level in the tank gets lower you will have less gravity flow so the pump has to work (suck) harder to maintain the pressure setting. A good farm supply store will have "suction hose" specifically for this application if thats your problem.

Also you said you have already tried to stop any air leaks between the tank and pump. Is it possible that as the water level gets low the pump is sucking air via a whirlpool or sloshing in the tank itself. Any air in the solution does funny things to your guages and regulators even on larger commercial sprayers. I have a large self-propelled sprayer and I have to turn my agitation pump off when I get below 150 gallons to keep from sucking air into the pump intake.

Hope this helps,
Russell

 

[plumboy]

Make sure your cap is venting.

 

[OrangeGuy]

Coosa,

My guess is that your roller pump is bad. I have had the same issue in the past. My problem was using Roundup in my sprayer. Roundup will destroy a roller pump after very little usage. You didn't mention if you used Roundup, but one of the herbicides you mentioned may also be as abrasive as Roundup.

Your roller pump can probably be easily disassembled so you can check the rollers. However, unless you have the new rollers it might be hard to determine if they are bad. Also the pump housing itself could be worn. A new Hypro 6 roller pump is about $65. It may be a good investment.

Check with your herbicide dealer to find out if the chemical you are using is recommended for standard roller pumps.

Good luck!

OrangeGuy

 

[coosa]

I went to the farm today and I THINK that the spayer is now fixed - many thanks for all the help here.

I first spent some time looking it over before hooking it to the tractor; I wanted to look at it and think about all the things you folks told me to check. It is a 6 roller pump, and the line from the tank to the pump is 3/4" and not 1" as I thought. The tank is vented ok.

I took the line between the pump and tank off and retightened the hose to the fittings. The only strainer is in the fitting where the hose attaches to the tank. It had a little debris on it, but wasn't stopped up. I hooked it up to the tractor, put 25 gallons of water in it, and sprayed it out over a field. It held 50 lbs of pressure for about 10 gallons, then dropped to 25, then to nothing. I got off the tractor and checked the main hose, and it was showing signs of collapsing in a couple of places. The pump was obviously sucking hard, but not enough water was coming through the line.

So I checked the strainer, and there was a little debris on it again. It still didn't seem to be enough to cause a problem, but I washed the tank out as best I could. I took the main hose off and reinstalled it so that it was perfectly straight in the hopes that it would have less of a tendency to collapse. Then I decided to check all of the fittings again to see if there could be anything that was letting air into the system. I noticed that the pressure gauge could be turned slightly, so I decided to try to tighten it down. I was afraid I was putting too much pressure on it and was about to break it, but I managed to make a complete turn with it.

I put another 25 gal of water into it and tried again. This time the sprayer worked perfectly. The loose pressure gauge was definitely a problem - instead of bouncing between 40 and 60, it stayed right on 50 and didn't move at all. It stayed there until the tank ran out of water. It came from the factory with this problem; it has always bounced around and I thought it was just normal for it.

I'm not sure what I did that fixed it. Could the loose pressure valve have been the main problem all along? I guess the real test will come in another week or so when I spray with 2-4DB, but I am far more optimistic about it than I was earlier.

Thanks again to all who helped me.