Broken again, loosing faith

[vtsnowedin]

My dealer removed the detents on the rear remote lever so that you would not accidentally push the lever into the detent and not know it, and deadhead the pump. The loop sounds like a good idea if you want to preserve the detent function. Say if you wanted to operate a log splitter you would shove it into the detent. My dealer said that is why they invented bungee cords. With the detents removed you would have to intentially hold down the lever to deadhead the pump.. I guess they were tired of replacing pumps under warranty.

James K0UA

This sounds odd to me. When a piston gets to the end of its travel and the relief valve opens the fluid that passes by the relief goes to the low pressure return line to the hydraulic reservoir tank. Having a quick connect would be the same as having a piston fully extended at all times. Of course if the control valve is set to call for fluid to pump to that hose it would make the pump work at the relief pressure all the time which might not be a good thing for some pumps but if the relief valve is set right I would not think that was a problem. If you hook up the suggested loop and then open the valve carelessly you will be having the pump pump oil uselessly which will do no harm but waste fuel. You ought to be able to hear the relief valve whine as it works when you are pumping against a dead head or fully extended cylinder.

 

[k0ua]

This sounds odd to me. When a piston gets to the end of its travel and the relief valve opens the fluid that passes by the relief goes to the low pressure return line to the hydraulic reservoir tank. Having a quick connect would be the same as having a piston fully extended at all times. Of course if the control valve is set to call for fluid to pump to that hose it would make the pump work at the relief pressure all the time which might not be a good thing for some pumps but if the relief valve is set right I would not think that was a problem. If you hook up the suggested loop and then open the valve carelessly you will be having the pump pump oil uselessly which will do no harm but waste fuel. You ought to be able to hear the relief valve whine as it works when you are pumping against a dead head or fully extended cylinder.

Well I am not a hydraulic expert by any means, but I think that if you had a loop, and pushed the control valve into detent, you would not develop much pressure at all, as the fluid would be returned to tank. The pump does not make pressure, it makes flow. Pressure is developed when the flow works against a restriction. When you apply flow from the pump through a control valve into the piston of a cylinder, pressure will start to build instantly and they piston will either move lowering the pressure or the relief valve will open to relieve the pressure. When you apply flow thru the valve to a deadhead of a connector. then the pressure builds instantly and the relief valve opens and the flow is at relief pressure all the time and builds heat and makes the pump work harder. When you have a loop, between the connectors, not much pressure builds, only the resistance of the flow from the resistance of the hoses and valves and connectors. It is some but no where near the relief pressure. As for the "you should hear the pump in relief".. Yes I agree, you should, but some people might not notice it.

James K0UA

 

[vtsnowedin]

Well I am not a hydraulic expert by any means, but I think that if you had a loop, and pushed the control valve into detent, you would not develop much pressure at all, as the fluid would be returned to tank. The pump does not make pressure, it makes flow. Pressure is developed when the flow works against a restriction. When you apply flow from the pump through a control valve into the piston of a cylinder, pressure will start to build instantly and they piston will either move lowering the pressure or the relief valve will open to relieve the pressure. When you apply flow thru the valve to a deadhead of a connector. then the pressure builds instantly and the relief valve opens and the flow is at relief pressure all the time and builds heat and makes the pump work harder. When you have a loop, between the connectors, not much pressure builds, only the resistance of the flow from the resistance of the hoses and valves and connectors. It is some but no where near the relief pressure. As for the "you should hear the pump in relief".. Yes I agree, you should, but some people might not notice it.

James K0UA

I think we are 100% in agreement only describing it in slightly different ways. Back years ago when I owned my first loader on a David Brown I would have trouble with contamination in the spool valves. I thought I had a pump failing. The Mechanic showed me that if you put the loader all the way up so the pistons topped the sound changed as the relief started to whine and kept whining until you released the up lever.That was the test that showed that the relief was working and that the pump was producing enough flow to build pressure to the relief psi setting.

 

[k0ua]

I think we are 100% in agreement only describing it in slightly different ways. Back years ago when I owned my first loader on a David Brown I would have trouble with contamination in the spool valves. I thought I had a pump failing. The Mechanic showed me that if you put the loader all the way up so the pistons topped the sound changed as the relief started to whine and kept whining until you released the up lever.That was the test that showed that the relief was working and that the pump was producing enough flow to build pressure to the relief psi setting.

Ok..I agree:thumbsup:

James K0UA

 

[phiferpharm]

You can hear a pitch change- it was one of the first things the delivery guy told me about and showed me when he delivered the tractor. Could you miss hearing it? Yeah, when I put on my sound suppression head phones and play a book-on-tape it might go unnoticed I guess.

 

[IslandTractor]

As I understand it, Kioti in their infinite wisdom has a remote which will lock into position and stay there. This causes either a deadhead or all of the fluid going through the relief valve and has been known to cook the hydraulic pump.
See: http://www.tractorbynet.com/forums/kioti-owning-operating/144079-getting-screwed-warranty.html for an example.

Aaron Z

Of course the remote locks into position. How else could you use it to power a log splitter or other device when not sitting in the operator station.

It is the operators responsibility to insure the remote is not deadheaded. One simple way to do that is to use the loop.

 

[aczlan]

Of course the remote locks into position. How else could you use it to power a log splitter or other device when not sitting in the operator station.
It is the operators responsibility to insure the remote is not deadheaded. One simple way to do that is to use the loop.

Mechanical lock that requires user action to lock it open?
IMO having a control that can easily be bumped into and (by doing so) can cook your pump if unnoticed is at best a design flaw. If it wasn't a problem, they wouldn't have put out a TSB on it saying that that is not a warrantable issue.

Aaron Z

 

[schweizer]

justr a heads up, if your not hooking anything up to the remotes, place a loop in the lines so as not to accidently deadhead the hydraulic system. do this a few times and youll wreck a very expensive hydraulic pump.

The last time I went to my dealer, he said they supply this short U-loop of hose on every new tractor so they don't have to replace pumps. So I got one and use it when the backhoe is off. I've hit that remote w/ my leg before so can see it getting bumped into locked position when wearing earplugs and not noticing.

Marcus

 

[DK35vince]

I'm one of the ones that never liked the detents on the remotes. Still don't.
I always felt they cause more problems then they solve.
A latch for the handle would be a much better idea IMO. If you need the remotes to stay on you just flip a latch back at the remote handle and pin it in the on position. Simple, easy and a whole lot less likely to be left/put on by accident and not noticed.

 

[vtsnowedin]

The last time I went to my dealer, he said they supply this short U-loop of hose on every new tractor so they don't have to replace pumps. So I got one and use it when the backhoe is off. I've hit that remote w/ my leg before so can see it getting bumped into locked position when wearing earplugs and not noticing.

Marcus

Your mention of Backhoe raises a question. Are you talking a power beyond setup? I'm unfamiliar with the valves they use. I'm used to two types. One that requires hand pressure on the valve all the time you want to run a piston forward or back, release the lever and a spring takes it back to neutral position and all oil flow stops. This type is what runs almost all loaders and a lot of other things. A joy stick lets you use two of these types at the same time with one hand but from the oils point of view it is the same principle. The second type you find on things like my wood splitter where once you push it toward a position you can release it and the valve will stay open until the cylinder closes all the way, then the relief pressure or a mechanical tab trips the valve and it snaps back to neutral and oil flow and pressure stop. These are very useful as you can trip the valve then use both hands to move wood to and from the splitter while the piston return cycles. One company used to make a splitter where you could trip the valve on the down stroke and the splitter would go all the way down and back without anybody at the control. This cut off more than a few fingers and they don't make them that way any more. :-(.
Now if you have a supply valve that sends oil to something like a backhoe or other high capacity implement it might not be set up to trip to neutral at each pressure spike to relief levels. If that's the case then a loop or a valve lock makes sense.