Dump pump air switch

[rockdog]

I put a new pump on my old chevy bobtail. I ordered it with an air solenoid to switch the pump on and off. It has two ports. One to push the spool control on,one for off. Seemed pretty simple at the time. Of course it came with no instructions. I can't find a in cab air switch anywhere on the net. I have a chelsea pto air switch but it only has ports for the supply air and pressure out. So it isn't gonna work obviously. So can someone with more knowledge about this point me in the right direction? This is my first dump truck so its a learning experience.

 

[lantraxco]

If you're just doing on and off, this will work: http://www.rcpw.com/truck-accessories/air-valves/BAV010.html

BUT, you say dump pump, are you needing to control up and down as well as engage a PTO or what?



You can google any of these part numbers and fine lots of places that sell them at various prices...

 

[rockdog]

If you're just doing on and off, this will work: http://www.rcpw.com/truck-accessories/air-valves/BAV010.html

BUT, you say dump pump, are you needing to control up and down as well as engage a PTO or what?

View attachment 124264

You can google any of these part numbers and fine lots of places that sell them at various prices...

Just the pump. The pto is set up on a floor shifter. Thanks for your help! I just want on and off on the pump, so that switch would work great!

 

[mitch504]

Don't forget on a dump pump, you need up, down, and hold; not just on and off.

 

[overworked]

Get yourself a feathering dump control valve, not just a up-hold-down, one that you can adjust the rate of decend. You will be most happy

 

[lantraxco]

I don't think he has a dump bed, running something else hydraulic maybe?

 

[mitch504]

Even if he's using for a lowboy or something else with it's own hyd. valves, I don't think that tailgate valve will do it, if it's a dump pump.

 

[lantraxco]

Pull it you got flow, push it, pressure line is hooked to tank return. No neutral, unless you don't hook up the second line. Ugly but it will work. Not enough information, not sure what the OP is trying to accomplish.

 

[mitch504]

Yeah, I guess it would, but he better be sure to hook up the recirc line from the pump or he'll be deadending the pump anytime he pushes it to cut off flow.

 

[lantraxco]

True dat.... like I said, not enough information....

 

[grandpa]

Dead end = Dead pump.

 

[rockdog]

Please educate me further. The control is for the dump bed pump. I guess I don't understand how the pump works. When it was cable operated, I thought it shifted the pump spool valve all the way out to let the bed down. And the switch he suggested would do that. I knew that I wouldn't be able to feather the dump bed down with it. So the switch he suggested will kill my new pump. Please link something else that would work. I don't need fancy stuff. This is a 1970 chevy C60 bobtail with a bench seat. So I need a dash mount of some kind. Please don't hammer me too bad, this is my first dump truck.

 

[rockdog]

Ok, so I have been trying to figure out why it is ok for the pto to run and the spool valve shifted with a cable all the way to let the bed down and it isn't ok to do the same with an air switch? Went to a site that muncie has to let you know how dump truck pumps work. My setup is two line on my truck. The cylinder has an external tank on it that holds the return fluid. I know, way old school! In their tutorial, it shows the fluid recirculating inside of the pump when in neutral. What am I missing here?

 

[overworked]

Yes it will recirculate when in neutral but it will build tons of heat and burn up pump in short time, the spool in the pump is three position that's why you need two air lines, if you put air to go up and take it away it might go back to neutral but won't go into lower, a three line hydraulic setup recirculates the tank oil when in neutral to keep pump cool.

 

[overworked]

Unless your dumping, you don't want PTO engaged, dump pumps are designed to be use intermittent, not continuously,

 

[rockdog]

Unless your dumping, you don't want PTO engaged, dump pumps are designed to be use intermittent, not continuously,

I understand that the pto doesn't want to be engaged all the time. Only when dumping. So what is different with the cable shifting the valve and air shifting the valve? Not trying to argue, trying to rap my tiny brain around why one is ok and the other isn't?

 

[rockdog]

Yes it will recirculate when in neutral but it will build tons of heat and burn up pump in short time, the spool in the pump is three position that's why you need two air lines, if you put air to go up and take it away it might go back to neutral but won't go into lower, a three line hydraulic setup recirculates the tank oil when in neutral to keep pump cool.

If I'm not mistaking the way the switch the first responder shows. It has an air supply port. And two ports out. When the switch is in, air is supplied to the port to push the air spool to the neutral (or down) position. When pulled out it supplies air to shift the spool to the engage(or up) position. Is my thinking off?

 

[overworked]

Would have to test it or get spec. Most have and exhaust port to release air.

 

[rockdog]

Would have to test it or get spec. Most have and exhaust port to release air.

Hmmm, that makes sense. So there isn't air against the actuator all the time.

 

[mitch504]

Yes there is air against it always. That tailgate valve Lantraxco posted would work for just up and down. If you ever needed to leave your bed up and get out to see if it was clean, or put a block in your tailgate or anything, and you didn't take the PTO out of gear, you have to buy another pump. What Overworked was talking about is that when you switch from the up position to the down position, if the valve couldn't let the air out of the "up" side, nothing would happen. That tailgate valve does have exhaust ports.

I would still strongly advise against using it, I would spend the extra, even if it's just a farm truck, because if you just raise it up and go to pull forward a little, you've got to stop and take the PTO out, or the engine's going to be straining to lift the bed farther than it can go. That's not good for your pump, cylinder, hoses or anything.

Even if you have a neutral position, leaving your PTO in gear for a while will overheat your pump, unless you have it setup with the third hose.

I once had a very good driver burn up a 1 day old pump because an idiot landowner came up and started having a screaming fit. The driver left the PTO in gear with the valve in neutral while he calmed the man down. The pump got so hot it melted nylon air lines near it. After I changed that pump twice in 2 days I put third lines on all my trucks.

In short, the pump running in neutral will ruin the pump after a little while, the pump running in raise, when the bed can't go higher, will ruin the pump almost immediately.