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slow hydro and won't move

Posted: Sat Oct 08, 2011 6:04 pm
by hobbit
Hi guys i have a 1914 and a 1572 that are slow to move and the hydro will stop under load. the fluid and filters changed and have replaced check valves i suspect the problem is in the charge pumps what do you guys think.

Re: slow hydro and won't move

Posted: Sat Oct 08, 2011 7:54 pm
by Tom Scott
Tracey - It is a bit of a coincidence to have two tractors with the same problem at the same time.

Did you have problems before changing the fluid and filter? Did you use a Cub hydro filter? Did you use IH/Cub HyTran or some other fluid? Are you sure the fluid level is correct? An off brand or incorrect filter could cause the problem you are describing. Have you checked the trunion springs and linkage to the hydro? Broken or severely compressed trunion springs will give slow/no hydro response.

Give us some more details to try and head you in the right direction. As far as troubleshooting further, the last thing you want to do is guess. Troubleshooting is best thought of as a process of proving that something is good, then moving to the next thing. Repeat until you find something that is not good. The charge pump pressure can be measured with a gauge as shown in the factory service manual, but I would find it odd for two of those to fail at the same time. The charge pump also operates the hydraulic lift, so if that works properly, you probably don't have a charge pump issue.

Re: slow hydro and won't move

Posted: Sun Oct 09, 2011 6:40 pm
by hobbit
I put another hydro unit on the 1572 to fix it. but now I'm trying to find out what goes wrong with these units so i can get them fixed.

Re: slow hydro and won't move

Posted: Sun Oct 09, 2011 7:42 pm
by FERGUSON
Tracey,

With the unit removed troubleshooting is limited and you will have to dissassemble it and inspect problematic area. The first step to address the questions Tom asked about fluid, filter and trunion springs. Assuming you have replaced the check valves with ones that are in working order, the next step is to remove the charge pump and examine the serface of the pump housing and gerotor as found in the factory service manual. Note: make sure you mark the orentation of the the charge pump housing before removing. Next inspect the contact serfaces of the center section and the cylinder blocks as found in the factory service manual. Take picture and post them where we all can see what you find. Good luck. Hydros rearly fail unless they have been operated with contaminated fluid or even no fluid causing damage to important contact serfaces of the transmission.

Re: slow hydro and won't move

Posted: Mon Oct 10, 2011 4:42 am
by vince_o
See what I work with! Franks all about that trouble shooting stuff. Also Tracy hes good with those tranny rebuilds. Im kinda scared of them, but I get to do one this week with him over my shoulder. It aint the taking them apart, its putting them back togeather that scares me! LOL

Re: slow hydro and won't move

Posted: Tue Oct 11, 2011 7:25 pm
by Jlaws
Tracey ,
I have a 782 that was sluggish . It wouldn't move till I had the hydro lever about half way and sometimes not even then . Then it would jerk forward and the hydro lever would chatter . I thought the trunion was bad until I put a pressure guage on the hydropump and seen the pressures were way down .
I thought the pump was getting weak but then I noticed that the previous owner had put a perolator filter on it , and after seeing that I decided to try another filter .
I had a new Steins hydro filter that had a toro/wheel horse part number on the box and after doing a little research discovered it crossed over to the cub cadet 923-3014 hydro filter . After changing the filter i noticed an immediate increase in the pump pressure . Now it moves with just a slight movement of the hydro handle and is smooth as silk . :beer:

It also used to freewheel downhill , the new filter also fixed that problem .
So I guess the pump was getting starved for fluid .
So either the perolator was the wrong replacement filter or it was more likely clogged .

I have a gentleman thats buying it and he seemed please when I informed him that it doesn't need a trunion repair . :lol: