125 Hydro problem

[namvee]

Hi

I’m a newbie and I’ve never really done the message board thing so please forgive me if I have miss posted this.

I recently bought my first cub (a 125 hydro) from a guy on Craigslist. He was a mechanic and said he took good care of it. I asked about the transmission and he said he maintained in regularly. I mowed the lawn once with no trouble. Last night though, I was mowing (again with no noticeable trouble) and after about an hour the hydro conked out while I was moving from reverse to forward. I took the sight plug out of the back and found there was virtually no Hytran in there. I went to the store and purchased a gallon of universal hydro fluid, simply with the hope of filling the reservoir and getting the tractor back to the garage. It took the whole gallon and it’s still low. And the tractor still doesn’t move. I also get a grinding sound when the forward/reverse lever is at the extremes of the range.

I’m hoping I haven’t irreparably damaged the transmission. Any thoughts? Next steps? Is there hope?

Of course, I’m kicking myself for not checking the fluid level first thing. But It really seemed to be working fine, and I never expected there to be NO fluid. Found a small puddle of Hytran on the garage floor, certainly not 7 qt worth though. Thanks for any feedback you may have.

[cmatthew]

did you check the lawn for hydro fluid. was probably dumping it out while you were mowing. i believe the manual says 7qts to fill. and also its says in the manual that the pump needs to be primed if its run dry. the draw/cooling tube needs to be filled to get the hydro pumping again. i would take a syringe with a hose/tube attached to it and run it up that cooling tube and pump oil to the hydro that way than fill it up and try. i cant say if yo damaged it or not. soemone with more knowledge on it will chime in soon. good luck

[Methos]

I'm sorry to hear about your problem.

[namvee]

Thanks for the info. I'll try that tonight and let you know how it comes out. I hope I didn't mess it up too badly. I've been trying to come by one of these cubs for a few years. I understand from collectors I've bumped into that they're increasingly harder to find in my area.

Thanks again!

[TheSaturnV]

Don't hit the panic button yet. The old hydros are pretty sturdy units. If it was empty and you just put in a gallon, then it's still very low. If it were mine, I would hold off trying to get it to move and do some service on the unit.

Get a catch pan, and remove the rear plate. It's time to see what's going on inside, and clean out the gunk. Any number of things could be happening, such as a blockage. Clean out the globs, inspect and wipe a rag across the bottom of the case to check for metal shavings. Some photos may help determine where the leak is as well.

I have a feeling that a new filter (Napa #1410), fresh fluid and a good cleanout will have that thing running good again.

[namvee]

Just to follow up on this. I split the tractor to get a good look at where the Hydro was leaking and found that a bolt the previous owner used to connect the rod that drives the pump to the engine had broken. This is what really stopped the tractor to begin with. Anyway, while I was in there, I took the back plate off and cleaned out all the gunk in the case as suggested. I also replaced the gasket between the hydro pump and the transmission. Put it back together and put in fresh fluid. Now it runs like a top. Thanks agains for all your help!

[ajgross]

The bolt you mentioned is actually supposed to be a solid steel pin. I would say that the coupler is probably worn and causing the pins to break. You might want to look into buying a new coupler and pin and fixing it properly so you don't have any more problems in the future.

AJ

[Sugarmaker]

namvee,
Welcome to the best cub site in the net.
I can see your not afraid of tackling a good sized project. Great news that you found several items in the splitting of the tractor and have it working again too.
As mentioned these Hydros are very tough and reliable but they do need some maintenance after 30-40 years and things get worn and need replaced.
I have a 125 basket case tractor I am trying to decide what to do with? Too many Cubs too little time.
Regards,
Chris

[teejk]

Dunno about 125's but on the 1250 the shaft connects with donut sized rubber "tire" disks at both the engine and hydro ends (same concept as a shear pin on an outboard motor...supposed to break before you really ruin something expensive).

I see I need to replace one of mine (it has a tear but 3 of the 4 bolts are still holding it).