There is a noticeable difference from left to right when I drive forward against a barrier. Does anyone have pressure tests and specs for this Thank You
You'll want to measure the charge pressure on the side opposite of the load... make sure it maintains 150+
Do you have a chart identifying the test ports?
This thread may help OR this one There is heaps of info here if you take a little time to search
Need advice, found damage to the left side drive motor, there is a pair of roll pins that keep the large plate from turning, I have repaired the motor and I am ready to reassemble. My issue is where did the pieces of the roll pins end up? I am guessing a complete disassembly of the tandem pump is in order. Having never done anything like this, order up a seal it and have at it?
I think a parts diagram would help identify what you're looking for and where they could end up.
We swapped the drive motor hoses and the problem stayed with the left side. We took the motor apart and found the roll pin for the thrust plate broke and there was also wear in the port end cover. We have the necessary parts to assemble but would like to find the service procedure for assembly before doing so.
If there is wear in the motor, there will most likely be wear in the pump...... Hydrostatics need to be repaired thoroughly or your wasting time & money..... You shouldn't even consider this type of a repair without a service manual - they are an essential item if you wish to carry out your own repairs. You'll find one on EBay. - be mindful that there are differences in the 1845C as it was a model that was sold for 10yrs. Serial numbers may be required.
I am stuck on this Case 1845C, Rebuilt the left drive motor and all was good for about an hour of running, unit lost all drive function, charge pressure only 70 PSI max and slow getting to 70. Inspected the relief valve no issue there, disassembled the tandem pump and found no problem in the charge pump. Anybody have a suggestion?
Can anybody offer any suggestions, we rebuilt tandem pump complete, there was a lot of damage. The charge pump was perfect. I still have the same issue with no drive, charge pump pressure only goes to 70 PSI at wide open throttle, it takes a few seconds to get up to 70 PSI. Please help
You will need to clarify " we rebuilt tandem pump complete". Precisely, what was damaged? Was there damage to one pump or both? Were new parts fitted for the repair? Did the repairer have hydrostatic pump rebuild experience? Was the rebuilt pump bench tested? "A lot of damage" indicates there was a lot of metal debris in the system - Were both drive motors stripped & cleaned? Were the loop hoses thoroughly cleaned before installation? Was the oil cooler flushed / replaced? Hydrostatic pump rebuilds, especially after a major failure, are a precise science - there are no short-cuts. The slightest amount of wear on any component will create internal leakage & loss of pump performance. The smallest amount of metal debris left in the system will undo the best pump repair job in minutes of machine operation. Frankly, the charge pump is the first thing to replace in any hydrostatic rebuild - regardless of what it looks like.
The failure I currently have is charge pressure will not build above 70 PSI at wide open throttle, it is almost zero at idle, exactly the same as before the tandem pump was rebuilt. All motors, lines flushed and cleaned, right side motor and pump were not damaged, left side pump was a wreck and rebuilt properly. I don't throw away perfect charge pumps, that pump is very large and even if damaged why would it just stop producing pressure like flipping a switch? Parts replaced left side pump: Cylinder block wear plate guide plate pistons bearings all seals
Does the gauge fluctuate all the time, does it give a steady reading when in neutral, or fluctuate only when the drive motors are running? Is the charge pump relief a cartridge or can it be taken apart and assembled?
gauge is steady, wheels don't even try to move, charge pressure 20 PSI idle 70 PSI wide open throttle, relief valve is a spring and poppet inspected and good.
If the charge pump is ok & the charge relief valve is ok - there is no reason you shouldn't have charge pressure while the LH & RH pumps are in the neutral position. Just to be certain we are on the same page, the "large" charge pump you are talking about - is the gerotor located in between the LH & RH variable displacement pumps - yes?
yes New i did a flow test pump drank up 2 gallons of oil in about 5 seconds
i did a flow test pump drank up 2 gallons of oil in about 5 seconds
If the pump is building to 70psi - it is pumping oil, it just just can't build it to the 320-340psi it needs. If both travel pumps are in neutral, any other leakage in the system is irrelevant - so if the charge pump & relief are good - it will reach the specified pressure. You really need to let someone who is familiar with these to take a look at it. Personally, for warranty reasons, I won't rebuild one of these tandem pumps - they always go to an authorised repair agent & are bench tested to verify they are in perfect working order when I refit them to a customers machine - it's expensive, yes, but that's hydrostatics & if they can't afford what I call the proper repair procedure, I don't get involved in the repair.
Fixed the issue, there was an assembly error (big Surprise) What threw me off was my charge pressure was exactly the same 70 PSI as it was before I started working on it. Lot of practice removing, disassembling, cleaning, inspecting and re-assembling. The next one will be easy. Thank You everyone for the help