forward but no reverse on my 125 hydro

   / forward but no reverse on my 125 hydro #1  

Machtech

New member
Joined
Jul 18, 2009
Messages
2
Hello fellow cub cadet people. I need a little help!
I purchased a cub cadet 125 Hydro to use as a plow tractor for my driveway. It sat for 3 years before i got it. It's running and drives fine in forward but won't even think of going in reverse. While in reverse i can roll it back and forth. I've been wrenching on machines for over 30 years so if it's internal, I'll fix it. I have manuals but they don't cover this problem.Any clue?????
Thanks, Mark C.
 
   / forward but no reverse on my 125 hydro #3  
It sounds like you hydro relief valve is stuck shut on the reverse side. Problem with it is, you will have to remove the entire transmission to fix the problem.

AJ
 
   / forward but no reverse on my 125 hydro
  • Thread Starter
#4  
OK,That sounds like it would cause my problem.I don't see it in my schematic. Also wouldn't it cause forward to have issues or is there one for each?
 
   / forward but no reverse on my 125 hydro #5  
One valve handles forward, the opposite valve is for reverse. If you can swap them you would have no forward but good reverse. The 125 had manual unloaders on top of the valves, meaning you can flip a lever to open the bypass so it can be pushed.

If this small plunger is depressed on the reverse valve, as often happens due to rust, you will have the condition you describe. They are sometimes tough to unstick, soak with PB Blaster penetrating oil and try to free up. Some guys use a wire welder, stick the wire to the plunger and pull it back up.

If you do get it freed up, it oftentimes will weep oil as the rust has entered the seat of the plunger. Best thing I've found is to do a few agressive FWD-REV shifts to stop these leaks. Keep safety in mind, no accidents please.
 
   / forward but no reverse on my 125 hydro #6  
You should have a small lever off the center console that would normally depress the relief valves manually so you could push the tractor.


They are on the front top of the transmission.
 
   / forward but no reverse on my 125 hydro #7  
As mentioned earlier, my first step would be soaking it with PB Blaster for a while and then tapping it to see if it will free up. Its worked for me in the past, but I had to be patient.

If that fails, the fix is swapping in a functioning relief valve. Not sure if you can still buy them new, but should be able to find a used functioning one.

I doubt you'll have to tear the the whole thing apart or remove the transaxle to fix it regardless.

Good luck,
Dave

PS; if the PB Blaster soak and tapping works, the aggressive FWD/Rev cycling does stop the leak!!
 
   / forward but no reverse on my 125 hydro #8  
Dascro, you actually do have to remove the transaxle to fix it. The narrow frames have no access to the relief with the transaxle in the tractor. That's why the narrow frame hydros are kinda frowned upon.

AJ
 
   / forward but no reverse on my 125 hydro #9  
Your right. I forgot that the 125 is a narrow frame. I always worked with the "newer " wide frames.

Thanks for making sure we provide the correct info to do the repairs right.

Dave
 
   / forward but no reverse on my 125 hydro #10  
No, you don't have to remove the transmission to fix it, just unscrew the valve with a 1" wrench, free it up, replace valve. Area very dirty, clean thoroughly before unscrewing valve. Just finished this job on my 129 10 minutes ago.
WHunter
 
 
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