Hi, im new here and i have a 1994 1845c. I work at a john deere dealership, i know my way around hydraulic systems or so i thought. My problems all started when the left side drive started getting weak. I checked stall pressure on the left side pump and it was 2000 psi. I removed the pumps and disassembled both the left and right pumps, only to find the valve plates had some scoring, the left side was the worst. Then i removed the left motor and disassembled it, nothing seemed bad. got a seal kit and reassembled the motor. Ordered new rotating groups and a seal kit for the pumps and i even ordered a tech manual. I assembled the pumps everything went together real nice. Got everything back in the loader changed the oil and filter, followed the startup procedure in the book exactly. Set the neutral position of the of the servos. Thought every thing was good, ran the machine about 10 minutes was working good. Then the left side started pulling down then a loud screech then left side wont move acts likes its locked up. My first thought was park brake but it wasnt. When i started it back up it would move again but the left side is making alot of noise. I hope somebody can give me some insight because this thing has got me stumped
Welcome bradseipel! That is a sad story. Nothing worse than thinking you have succeeded in a repair & then to hear the machine scream in pain...... All I can say is back to the drawing board, check & recheck components to see if it was assembled correctly, spend more money & time & hope it's right next time. I make a living repairing machinery, I hate hydostatics for this very reason - one mistake in assembly & thousands of $$$ can disappear. I always sublet repairs of pumps to people who know about them, they bench test when they complete a repair & it comes to me in guaranteed working order. Sure it costs a little more, but I love the peace of mind it gives me.
I'm having nsome of the same problems, what are the rotating groups you speak off? One dealer said there was cartridges you can change, same thing?
Welcome gyman98! The transmissions on skid steers are a tandem pump - 2 pumps joined together as one. There are 2 rotating groups, one for left side & one for right side. These are the main part of the pump - see pic - http://www.all-hydraulic.com/replacement-parts/eaton-rotating-group-70402-615.html The cartridges are relief valves that control the pressure. usually there are 5 - fwd L&R; rev L&R which are interchangable & charge pressure. What machine do you have? Describe your problem more ....... We are all here to help.
Thanks for your help, the machine is 1996 1845C. Before changing the oil and filter it would gradually lose power to the wheels as it warmed up. Seemed to push a bit them just lose everything. Like a relief valve popped. After filter and oil change the right side isn't to bad but the left still is but it is a bit better. Hope that helps
Well gyman98, you need to check pressures with a gauge - charge pressure usually tells all. Here's an earlier thread re similar problem (& it refers to another yet earlier thread) - HeavyEquipmentForums The fact it loses drive when hot does not look good - pumps & motors may need to be looked at. TIP - This is a problem that cannot be repaired by guesswork - if you don't have tools or knowhow - find someone who has.
Thanks for your help, I'll look for some guages
IOur old '96 1845C is on it's third main pump, right drive still very slow. Could it be the drive motor, a stuck valve, a gremlin....UGH!!! 1st pump installed by Case, worked ok for a month then started doing the same thing when hot. Second pump installed and worked for awhile and same thing. Put the 3rd pump in yesterday and the right drive did not hardly work from the start. It goes full speed in reverse.
Hi. We have and 1840 in the fleet which has no power on the rightside. We did a motor seal change and hose replacement then the side died with no power. Can anyone assist me in getting some information as to how to go about dissassembly, diagnosis, and repair of the pump. We need a workshop manual as well. Any suggestions??
Welcome ARMGUY! Check the above post #6 of mine it has good info for you. An 1840 has basically same pumps & motors as an 1845C - so all the info is relevent. You may have got something messed up in putting the motor back together, Why was it pulled apart in the first place? Drive motor leaking? Blown hose?
We first had a busted hose, the machine was starting to loose power on one side. When the hose was replaced, there wasnt much improvement. We decided to remove the drive motor and oput some seals in it. On the remount, the machine didnt work at all. no power. We removed the motor and rechecked looking to see if there are any timing marks associated that were mal-allinged. Still the same issue. We then swapped motors and the problem was still in the same place. So we understood that the motor was functioning but the tandem pump may have issues. Based on the previous threads we have opened up the pump and have seen some scoring on everything brass on the no pressure side. There are some stuff that look like bulltes, these are scored. When the cluster containing these bullet like stuff was removed, the mating face on the inside is scored and a depression can be felt against your finger like the face was dugg up. Similar to the feel you get when friction pads that are worn down too bad makes a metal to imprint on the rotor or drum. Thanks for the reply. Can you advise me on the way forward in getting a steps of procedure or manual to repair.
That sounds ugly - lots of dollars ...... do you have any test gauges? Do you have any hydrostatic pump repair experience? Service Manuals could be on Ebay or try MR Bean at http://casemanuals.com/index.html
Thanks again. We do have some gauges here and limited hydrostatic experience. Cassius
I dont have the manual but from the threads we went ahead and opened the pump. I found alot more wear on the piston retainer on the non driving side than the driving side. We sanded it down to make a flush finish. Will reassemble and see what happens.
Sorry ARMYGUY, sanding down hydrostatic items just doesn't sound right. That is sort of like a woodworking terminology.......I hope you meant to say - refaced the surfaces using a glass rubbing block. A few manuals on ebay at moment - http://www.ebay.com/sch/i.html?_nkw=case+1840+service+manual
Thanks for the link. We reassembled the pump but the pistons seems to be locked up. We are not able to turn the pump by hand. s this a normal feature or do you think that we have done something wrong? All parts seems to mate seamlessly but still we have that small issue. CAssius
The pump should not turn 'by hand' - but with the aid of mutigrips / vise grips it should turn, thats with all ports open & not capped.