Hi, I am new to the forum and looking for some advice. I bought a mid 90's Case 1840 Uni-loader skid steer. It is in nice shape and runs like a champ. I tried it out - even drove it home and it seemed fine. The problem is that once it gets warmed up, the drive motors don't have sufficient power to do any work. It will drive, but is sluggish. I took it into a shop and they diagnosed it as having a bad twin pump. They discouraged me from repairing it as they thought it was too old, would cost too much, and that replacing the twin pump could cause one or both of the wheel motors to then go bad. I have $7,000 in it. They offered me $3,500 for salvage. I brought it home and have had it several years. The loader is very strong and will lift the tractor off the ground, and if I only use it for a few minutes, it works very well. I am looking for advice on what to do with it. I bought it from a local guy who (I found out later) had tried to solve the problem and decided to sell it instead. I wouldn't sell it to someone else without telling them what I know about it - just what I wish he had not done to me! Nice guy! A rebuild kit for the twin pump is around $1,000. The shop also discouraged me from trying to fix it myself. They said it would be too dangerous - if not timed properly - will explode. A rebuilt pump is several thousand dollars. Anyone on this forum have any experience with this hydrostatic pump? I'd rather not loose my investment, but it is time to either fix it, or sell it for parts. I will appreciate any ideas you may have.
Welcome to HEF Rhomar! Why any repair shop would tell you this story is beyond me.... Every pump is repairable with parts. It just depends if the cost of the parts with labour will exceed the cost of new pumps. I would try to locate a Sauer Sunstrand agent. It is important to have both motors inspected, as any wear in the pumps is always reflected in the motors. Any money spent on repairing/replacing pumps is 100% wasted, without both the motors being visually inspected & repaired as well. Any good hydraulic repair shop can reseal & reface all mating surfaces to bring them back to near new condition. All hoses & fittings need to be thoroughly cleaned during reassembly. If properly repaired (which wont be cheap) & maintained, your machine will give you many years of service. You just have to decide if you wish to continue to spend money on this machine or not?
I don't know what they are talking about "timing" in relation to those pumps. I have not worked on one quite that new but the 1845's we had at various plants were not that bad to work on the pumps. Maybe not cheap but nothing that difficult. I think the ones we had were the Cessna axial piston pumps. We did have fair amount of luck getting some things resurfaced if not too worn. I do tend to agree that if you decide to try rebuilding the pumps I would also suggest and least clean and inspect the motors along with a good flushing of the system. If you could post a serial number someone might be able to look around for parts list or something to have a better idea of what you have. If you were in the NorthEast USA I might have a shop I could suggest, but AZ is a bit far!
You're getting good advice here.... here's my two cents: Case only shows one listing for the 1840 in the online parts, all the variations in pumps are Danfoss M46T, still current production at Danfoss, parts are readily available and any good pump shop, or reasonably able mechanic could probably rebuild one. I just quoted a guy a new set for a Morooka, slightly different as they use an external charge pump but it was $4,500 out the door, four week lead time. The motors are geroller type and are much more likely to fail than the piston pumps in my experience, YMMV. I would check filters, check charge pressures, check the motor drain lines one at a time, and if the flow seems high probably yank one motor off for disassembly to check for internal wear, lot easier than pulling the pump stack. I send all my Danfoss stuff to Memphis if I can, or Aurora Ohio... you find a horse you ride it, most all of the hydro shops in my area are crook. Won't put a used unit on their test stand because it might contaminate it, charge you a grand tear down and inspect, quote you the price of new to rebuild it, and hand you the bill for a grand and your box of parts if you don't pony up. No thanks. Let us know what you find!
Sounds like this shop is feeding you a line to get your machine for cheap so they can fix it and sell it at a profit. The problem could be the drive motors and not the pumps. I needed a new drive motor in my skid steer because the seal was leaking into the chain case. They sent the motor out to a repair shop but said it was too far gone. The motor was $1300 but I think a lot cheaper than a pump. To lift the front of a skid steer doesn't take much lifting power.
Welder Dave makes a good point! A weak pump or a motor with internal leak could be the problem. Also as lantraxco says check the motor drain lines, those should, if like other hyd. motors, be the smaller lines coming off the motor. They are more or less vent lines to keep pressure off the pump seals. A little oil coming out is normal, probably an actual spec. somewhere, but if you are getting a nice strong ****** that is NOT GOOD! That indicates internal leakage. I don't have access to test spec's for your machine but as an example on a much larger system Cat 350 Excavator! They say to block the tracks so it can not move then hold full drive pressure on the motor of close to 5,000 psi for a minute and measure the case drain volume. On those big drive motors at that pressure the new spec. is 7.9 gpm and on a rebuilt motor 9.1 gpm. Hopefully some one will have the spec's for your machine.
How many hours on this loader out of curiosity? Did the shop who diagnosed the pump, give any indication what pressures they were seeing? We recently had similar discussion with Rico7467 and his 1845C, that would lose power when his loader warmed up, a lot like you're having. Probably not related but worth reading his posts (this and pg 2). HeavyEquipmentForums
Arizona Case 1840 Ok, thank you! Here is the serial number for my skid steer: JAE0188517. I was told that it is a 1993 model. It has 1541 hours on it. It looks as though I am going to have to sell it, and wondering what some of the forum members think it is worth - as is? It is a great running machine -was only used lightly for snow removal by DPS. Since it was in AZ, it was probably only used a few times each winter. It works very well until the hydraulic oil warms up, and then the drive motors get sluggish. I can not imagine what happened to it. I have not abused it in any way! As I mentioned in my first post, I was told that the twin pump needs to be rebuilt or replaced. Other than the hydro-static problem, you probably won't find many skid steers of this vintage that are in this nice of a condition! It also has foam in all 4 tires. Thank you in advance for any advice.