I am building up a new service truck and mounting a full hydraulic Liftmoore 6K crane on it. The truck is an '06 International 4300 with Allison auto and a Muncie PTO which had been used for propane delivery. My research is showing it to be a 7-900 RPM output which without a speed increaser, won't direct drive a gear pump fast enough. I had been looking at building a gas powered hydraulic sled unit but it will take up a lot of room in my bed. I do have a John Deere 23cm 9 GPM radial piston pump from a cotton stripper salvage job and am wondering if it could be used in and open center system for the crane and outriggers. I would mount the pump under the bed and run a jack shaft to it with an overhead reservoir as it had on the stripper. It would never be able to go to standby but they can handle constant operation. Ford used piston pumps on their smaller farm tractors in open flow. Volume would be reduced as it wouldn't be turning at normal engine speed but it would probably be fairly close to my 6 GPM need. My I&T manual for the tractors that run this pump showed a flowmeter rating of 5.5 GPM at 1000 RPM. Anyone ever tried this or seen it done? Any input is greatly appreciated before I jump off into and unknown build!
wouldnt waste the money when you can buy a gear pump for a few hundred dollars
For example https://www.surpluscenter.com/Brand...-GP-F25-34-S13-A-Hydraulic-Pump-9-12242-C.axd
If you already have the pump and no use for it, I don't see why not. It will go into standby if your relief is set higher than standby and you deadhead or stall the hydraulics, otherwise it should work fine. Is the objection the cost of a salvaged pump? I'd rather have a relatively simple but well built piston pump rather than a cheaper built even simpler pump.
The Deere radial piston pumps I'm familiar with use high pressure to hold the pistons off the cam ring that drives them. In an open center system you would never go into standby. Do you have any idea of what the operating pressure might be for your crane?
Thanks for replies. I have the piston pump sitting on a shelf gathering dust at no further expenditure. All I will need to procure is a jack shaft as I have several salvage reservoirs to choose from on various junked farm machines. These pumps are usually set around 22-2400 PSI to destroke and then a lesser pressure keeps pistons off cam roller until standby pressure drops and pistons fall back and resume pumping. In an open center application, other than reaching standby pressure in a stall, it will always be in operation. One other aspect that is drawing me to this build is a piston pump in theory doesn't drop pressure as RPM's decrease as a gear pump does due to leakby, so a low speed PTO drive wouldn't be a problem other than flow volume. My crane specifies 2750 PSI and 6 GPM (for optimum performance) and these pumps can be turned up in pressure to some degree, enough to meet my need. The big question was mainly will this pump function properly without the deadheading of a closed system.
I'm thinking it should work even though it never reaches standby. Really when you think about it, the Deere pump is basically a fixed displacement just like a gear or vane pump. It just has the additional provision of being able to go into standby when at high pressure. They used to use horsepower summation in excavators back in the big gear pump days. Mounting and plumbing might be the biggest hassle in the installation.
Much obliged for idea confirmation! Doing a direct under bed mount and drive and plumbing will be much easier than the gas powered skid I had originally planned to build. Its amazing how quickly I was going to fill up a 4.5' by 15' bed with an air compressor, 6K crane, welder, and then a hydraulic power unit! I'll have to get the air shift and idle up controls for the truck which shouldn't be too hard to come by. I'll call Vander Haag's where I got the bed and see what they might have salvaged.
I personally do not particularly like the jd radial pumps-there are too many potential problems especially older designs such as broken springs in the inlet and outlet valves, valves coming loose in the housing, etc. especially if they are used at maximum flow for any length of time. the early ones were not designed for continuous flow but low flow and high-pressure standby with only occasional max flow. they are not a pretty sight when they grenade and expensive to replace. I prefer axial piston pumps ie.-fixed displacement, variable displacement, or bent-axis. they are also expensive. gear type is cheapest and simplest for this application. if the oil gets too hot you would also need a cooler. just my 2 cents
I don't know where you had your problems but they were used in Haulpak trucks for the steering a brake system and in over 5,000 hours of operation that I saw, they never gave us a problem. Maybe the application makes a difference?
ag tractors( 20,30,40, and 50 series) and 410 backhoes( approx. 5000hrs and above). the ag tractors mostly gave problems when there was a need for continuous max flow like running air seeder fans. the bigger displacement pumps weren't as bad because they weren't running at full stroke unless they were running 2 fans at once. they could also blow the valve plug threads out of the housing if the stroke control valve wasn't set right or stuck(if I remember correctly). the early ones were only set to 2250psi because at that time that was all that was needed. nowadays we need at least 2500 or more in a similar application. if an engine was hard starting ( cranking hard), because of the hyd pump load, an electric destroke kit could be added to the stroke control valve.
I see your concern. At least wrwtexan will know what to look for should he have a problem.
oh ya, the radial pumps usually need a charge pump to supply oil to the inlet. I don't remember how much pressure but I can look in one of my manuals if you need to know- probably about 30 psi
I remember Condor man lifts using Deere radial pumps in open center hydraulic systems, I don’t remember them having a charge pump though.
that's why I said 'usually' I don't know if gravity or head pressure would be enough
Yeah no problem 56, it’s been 8 years since I’ve seen, let alone worked on a Condor. I just don’t remember if they had a charge pump, may have had one, memory is foggy anymore .
Have you actually engaged the current PTO and tried to check RPM's on it? And I'll just throw these two other ideas out- 1. I would think a used pto and mated pump would be super easy to source from vander haag's. All those bucket trucks are allisons. And I usually don't give much for used Pto's with pumps. 2. I think what some of these guys are doing with a electric hydraulic pump like a tommy lift or a rollback bed have, would be really slick to use the truck inside a building. Also not have to have the truck running all the time in the field. Put a dedicated deep cycle battery on it and a charger to use plugged in in the shop. Run the truck a little when the deep cycle gets weak out in the field. Have a battery disconnect so you don't drain the truck batteries with the crane battery. I would think a electric over hydraulic would last quite a while in the mechanic crane use. It's not like you're running it all day long up and down and in and out. Most of the time when we use our 4k, its for less than a minute, then sits still for 5 or 10 and bump up and down placing something. Rarely does it run a lot for a extended period of time. I don't have that on ours, but I've seen pictures of other's, and really could see how that would be nicer than having the truck sit and run all the time.
does that IH have cruise control if so it can be throttled up and down for your pto throttle
just for curiosity sake I checked my old 772BH manual and min charge pressure oil warm was 3psi at idle so maybe a gravity feed system would work if the oil is not too thick(emphasis on maybe). the jd spec is for Hy-Gard fluid or universal tractor-hydraulic fluid
As far as charge pressure, on the tractors, they were pressure supplied as the trans is several feet behind and a few inches below the pump. On the cotton stripper, it was pulling straight out of the reservoir filled with red ATF. I have seen and very recently the repaired the damage of a grenaded pump, wow what a mess. That tractor still doesn't have a working rear lift from the shrapnel through the system but that'll have to wait for his time crunch and finances to ease... Crane op; I will call Vander Haag's and see what they could do for me on a used complete unit. One question though is how common are units which will generate the 2750 PSI the crane calls for? The few I've dealt with are high volume low pressure units on scrap tippers. One other function I plan to use the hydraulic system for is to have a set of remote couplers to run hay balers, plow lifts, and a tractor wrecker trailer, so I think the electric route won't meet my need. With my line of generally farm repair work, I rarely see an enclosed building to work in, much less one tall enough to raise this monster in or tight enough for exhaust to be a problem. Hatch; If it has cruise, I haven't driven it enough to find out. User manual is gone and I'm not sure what which buttons on the steering wheel do yet. Great responses and thanks!
On 310/410 Backhoes that used the radial piston pump the charge pressure spec is 30-50 psi minimum depending on model (all levers in neutral). I remember we would lift the loader arms at idle while watching charge pressure and so long as it remained positive you were good. I think a charge pump would be necessary. I don't think gravity would be enough.
So are you going to run ATF, universal tractor, or AW 32/ 46? I don't know that it matters much what you run, but I don't know that I would want my crane tied into everyone else's hydro systems from a cross contamination standpoint. I don't know that I would get real hung up on the 2750 number either. It would probably work just fine at 2500. Remember the 6k number is straight up, and not very far out. Realistically your going to be able to handle 2-3,000lbs max. My 4k will not load a 3406 cat into the pickup bed by itself.
Crane op; good point on the oil. Likely will run a good AW32 universal HY Tran for that aspect. Never having had a crane like this, I'm just going by Liftmoore's specs on it for PSI requirement. mg; I'll be going by the salvage stripper and verify, but having pulled the engine for another machine, it was straight from tank to pump as I remember.
I think far left dash rocker switch, maybe 2 one on off other accel. decal. Some of the boom truck tie into these circuits for throttle.
Gravity will be no problem if you have a desent supply hose . All the JD tractors had a gallon reservoir 2 feet above the pump to briefly top up on the half capacity charge pump . You are not going to have the pto running 10 hours a day so if the pump is in good nick even with it in constant pumping it should last years . They can and do give trouble in tractors ,but not a lot imop . The are great to supply high pressure young or old,hot or cold ,running fast or slow .
I called Vander Haag's in Kansas City today and was told new was about all they had (not much effort to say otherwise) so I'm going ahead with the JD pump plan. I'll post info and if I can figure out how, pics also. Thanks to all for valuable opinions and info!
We have a 544C loader with 15k plus hours on it wityh the original pump, I love them.lol They will gravity feed just make sure the top vent line goes to top of tank if it has one. And the inlet doesnt have a check valve, being already gravity feed it likely doesnt.
The radial pump works perfectly for this crane! I have an 8G tank mounted in the bed directly above the pump for gravity feed and outflow is going through a selector valve to outriggers valve or crane system. My truck does have cruise/idle set on the steering wheel but so far it has performed great at idle. I would highly recommend this setup if anyone else needs a low RPM high pressure hydraulic system. This crane has become our favorite tool on my new service truck. With the hydraulic outriggers, it is steady as a rock and the pedestal it is mounted on is secured into the 4x6 box beam frame for a 60' reach bucket lift that had been in the bed. Thanks to all for the idea confirmation!
I sure wouldn't trust that bracket based on the weld I can see. Would be worth having an experienced welder grind it out and weld it properly. You wouldn't want it falling off.
Jd piston pump needs charge pressure...in tractor charge pressure is supplied by transmission pump...charge pressure is maintained by the priority valve that supplies oil to steering and brakes first then charge to piston pump...also make sure final rpm of pump drive does not exceed 2100 rpm.