View Full Version : 1978 JD 2040 Hyd problems

04-05-2012, 11:38 AM
My old JD has always had a small leak on the steering column and after a long days work always got a little hot. the tractor is a 2wd with power steering and does not have high- low. the tractor was made in Germany. Last week while running a new (very large) brush hog I hit something in the field and thats when the problems started. the power steering quit working and the three point and the auxilary hydraulics all quit working at once. I changed the filter and checked the screen and did not see any thing unusual. I checked to see if I was getting flow to the front pump and 0. It must be something in the rear pump? I am told by the dealer that there are a number of things that could go wrong back there. O rings, or maybe some tubes that come from the rear pump and go to the front pump? All of these they say are inside the rear housing and will require the tractor to be split. has anyone had this problem and is there any other way to get to the problem besides splitting the tractor? Can you go in front the top? How can I tell what the problem is before tearing things apart?

04-06-2012, 09:11 PM
Since the problem started when you hit something with the rotary mower, I am guessing you probably broke something in the pto clutch or pressure plate. The transmission pump is driven from the pto clutch if you have a two stage clutch. If you have independent pto, it is driven from the pressure plate. Will the pto still run? Is it independent? On independent, there is a lever between the two shift levers that you raise to engage pto. On two stage clutch, you push the clutch down all the way to stop pto and the shift lever is by your left heel. Either way I am guessing tractor needs to be split.

04-07-2012, 09:21 PM
The pto still works, I cracked the lines going to the front pump and ran the engine nothing comimg out so I pulled the filter and housing and ran it, still nothing, so i pulled the top cover off the transaxel and could not see any problems. I again ran the engine and nothing. There is oil flying around up front you can't really see down in there but it is where the pto engages and I believe where the oil pump is located. I fear the worst and unless anyone has other ideas my next step is to slip the tractor.

04-07-2012, 10:16 PM
Having Identical problems as you unclemike. Same exact tractor 2040 Germany and followed same procedures as you, new filter, new fluid. Best as I can tell, the pump in the transmission provides pressure to the pump in front of the radiator. If you disconnected the output line from transmission to the inlet on the front pump and had no flow, then the pump in the transmission has quit. I am waiting with baited breath for someone with more experience with this tractor to chime in. Sorry to hear about yours, I can say, I know how you feel.

04-08-2012, 12:32 PM
If the pto still works, then the pump is turning. Either the pump suction tube#14, outlet tube#10a or 10b, is broken or leaking, or the pump gears could be broken. When you removed the cover, I assume you meant the cover with the shift levers in it. The tractor needs to be split at that area to find the problem.

04-09-2012, 01:32 AM
Thanks for the diagram. The cover that I removed was the top off the transaxel. it has the two lift arms and lift cylinder. I believe that your right about the those tubes. One of them must have come apart. Now to split the tractor apart what do you do about the shift levers? And does the thing come apart just like pulling a manual transmission? With a splined input shaft? I guess I'll find out tomorrow once I figure out how I'm going to support each half and then pull it apart. Thanks again I'll let you know what I find.

04-09-2012, 09:57 AM
Be careful, & good luck!!

04-10-2012, 08:47 PM
You need to remove the shift lever cover. There are two additional bolts under that cover that holds the two halves together.

04-11-2012, 06:15 PM
I brought an A frame with a chain hoist home last night and will attempt the split tonight or tomorrow.

04-14-2012, 10:05 PM
Well I got the tractor split apart. It took most of the day but it wasnt that bad. The gears in the transmition pump are blown apart. The pump housing and every thing else looks very good. I was able to account for all of the gear teeth and there isnt any metal anywhere. I think some new gears and a gasket set and I'll be putting it back together.

04-15-2012, 10:02 AM
Glad to hear it's no worse than that.

04-18-2012, 02:59 PM
I found parts and ordered. could not find just the gears. I was advised not to use an aftermarket pump. I found a reman that has a 1yr warranty so thats what I went with. the pump should be here by Friday just in time to spend the weekend putting it back together. I'll post the final out come.

05-01-2012, 10:18 AM
I cleaned and flushed the system out and installed the new pump and put everthing back together and it all seems to work fine. Putting the thing back together was not as bad as I thought, it went back nicely with very little effort with just one person. Thank you all for your support and good luck to all who must do this in the future. I think what helped me the most was a concrete floor in the shop and the use of the rolling A frame hoist.