hi, has anyone rebuilt a case 1830 Left hand hydro pump.I need to rebuild/repair mine and want to know how difficult it is or what areas of the pump would fail first, and any pics would be good.
They are not difficult to repair. The most important thing to remember is clean, just a small particle in the wrong place can shorten the pumps life. When you disassemble it if you are unfamiliar with the internals, take lots of pictures and have the exploded parts view handy. Unless it gets apart on you quicker than you wanted, mark the rotating cylinder and the pistons so they go back in the same hole. Check the fit of the slippers on the pistons, both for wear and any cracks. Check the pistons for scoring and pitting on the face. Check the pressure face (what the cylinder runs against) for scoring and cracks. Inspect the spider and pivot for cracks and fit with the slippers. The splines on the drive shaft should be a good fit with the cylinder and bearing surfaces should be clean and a good fit. Check the surface of the swash plate where the slippers ride, if the surface is rough it will eat up the slippers. I always replace the loading spring just because it's difficult to judge the correct spring tension and if a coil is cracked and not noticed, well it's cheap insurance. make sure the valves in the body are a good fit and not sloppy or sticking. Everything else is just normal mechanical stuff, seals, bearings, gaskets. Just take your time and if when done you think you forgot something, take it apart, it's already on the bench and a lot easier now.
Thanks BillG, that's very helpful. Do you know what is the common area of failure in the left pump, or the part/area I should look at carefully when I take it apart, are parts still available?
Go here, there are two different pumps but basically the same design. I don't know what the prices will be down under but when you get it apart you can call your local Case dealer and see what they charge. As far as what usually goes bad, it's hard to say. What is yours doing or not doing? http://www.colemanequip.com/Case-18...-PUMP-CESSNA-NO-70142-DAC-0rDg/?#partdiagrams
It's not driving the left side motor, is swapped right hoses to left motor and it drove ok, so issue is in the left pump.Case Australia have parts listed, but no longer available, so will have to source parts from US.
Did you check the relief valves and replenishing valves? It maybe nothing more than a stuck valve or bad seat. Also did you check the linkage at the pump? A missing pin and the pump stays in neutral but the linkage still moves.
We had some 1845's that had the same basic pump years ago. The problem we had with some were the contact point for the Piston block ( figure #19 ) and the backing plate ( figure #25 ) in the parts diagram BillG sent. On some of them we were able to restore some pumps to working by having a good machine shop surface grind them. I'm sure the cause of the failure was poor maintenance on our units. As around here skidsteers have been treated like the wooden handle shovels they replaced, when done being used just drop and walk away! Also I'm sure our reground parts did not have the life of new but you have to make the call on that one for yourself. If you are using it 40 hours a week then new might be the best option. On the other hand if only used a couple hours a month doing yard work on the farm the reground might last several years.
The linkage is ok, I haven't checked the relief valves as yet
ok i pulled the tandem pump assembly out today and stripped the left hand pump out, and i found the rotating group and swash plate totally destroyed.the pistons were jambed in the housing and bits of metal stuck in the outlet pipe, bit messy really.Now im thinking that the right pump may need looking at. What would be the reason for this failure, lack of oil maybe?
Hard to say the cause other than "Poor maintenance" of some kind. With that kind of damage I would say anything that has contact with the hydraulic oil in this thing needs to be removed cleaned and inspected for damage. This would include the hydraulic cylinders and flushing out oil cooler. Anything less and you are just asking for a repeat of this or another failure.
Judging from the condition of the swash plate I would guess a slipper failed. The grooves didn't happen instantaneously when the pump failed. Also look at the load spring (between the slippers and cylinder barrel) and see if it's cracked or broken. A loss of spring pressure will allow the rotating block assembly to loose contact with the pressure head and start to chatter thus starting this problem. Also make sure when you add new oil to include the Case special additive.
Only takes a small contaminant to start this type of failure, ie - something that enters the system during a hose replacement. Bad side of this story is that the drive motor will look exactly the same ........ big dollars required to repair. Next, ask yourself is it worth spending that sort of money on the old girl?
Also, be aware that when you swapped hoses to the right side, you contaminated that side as well. You would b best served to pull it down for a clean out as well.
I checked the right hand pump and it is in perfect condition, no traces of metal fragments anywhere, will check left motor on weekend.the hoses I swapped to test were from right pump to left motor, I found it moved then changed back.
what is my next move, do i replace pump or just rotating group and swash plate, everything else seems fine.
Pull the LH motor & strip it. Get any ID numbers off the pump & motor. Get the original Case part numbers for what you need to repair & replace. Get on the phone/internet & see what is available in the way of parts & new components. What is gonna cost & can you get parts??? Don't think of second hand, unless it is pulled apart & you can see the condition of the components. Keep in mind EVERY HOSE & FITTING (including cooler & return) will need to be removed & flushed. The oil cooler will need to flushed, when you do this, catch the flushing liquid in a clean container & look at what comes out. In bad cases best to replace the cooler as it near impossible to get the metal out of them....... Even drain the hyd tank & flush it out with kero or diesel. Any little bit of metal left in the system, will have you doing this whole repair again in no time.......
does anybody know if the surface of the swash plate can be machined flat, as this part is very hard to get.
With the amount of wear that you have, it will have to be built up and reground. Remember that removing that much material would weaken it and also lower the pressure applied by the spring and change the displacement to the left side.