Cub 127 Hydro Issues. Just joined!
 

Hi all! I just joined here today. I picked up a Cub 127 Hydro I think a 67-70 model. Got it running and had to free up the plungers in the check valves last week. All was going fine after some WD -40 and cleaning them off. That was last Sunday. It's been in the garage all week. It started today easily and after I let the engine warm up I tried to back out of the garage, no movement, nothing forward either. This thing sat for a few years in a barn before I got it. I figured I'd change the hydro fluid and filter since I was having issues. I noticed the old hydro fluid had tons of tiny air bubbles in it when I drained it. I put in new fluid and filter and same result. When it is running both check valves are up but there no pressure behind them. Not sure if there should be. Some one told me to purge the line for air or it may be the valves. Any thoughts, opinions, advice would be greatly appreciated. Thanks in advance!

First, welcome to OCC.......... :Welcome2:

Check the Hydro Unit "input shaft" to see if it is rotating at the same speed (RPM's) as the drive shaft. If not, there is a broken Spirol Pin to the coupler on that input shaft.

Thanks for the welcome and the reply. So here's the latest. After I posted this I decided to take a break and eat. When I went out an hour ago to push the mower in I decided one last try. It fired right up and moved forward and backward with ease at idle. I made a small pass through the yard, sitting on the rear axle, and backed it in the garage. Ran just fine like last week. What's the deal? I also noticed that when I drained the fluid and had the back cover off the case was lined with what seemed like a thin coat of clearing jelly? Is that from old hydro fluid? Thanks!

Sounds like you might want to change fluid and filter again and make sure you clean out the rear really well and get all that stuff out. You may have had air in it each time and it bled out on it's own. Probably good to do one more change.

Thanks! I'll give that a try as well. Should I worry about wiping all that jelly like junk out? Or as much as I can?

Yes it will cause problems, it is an emulsion of water/oil,wipe it out and flush it out with kerosine or your favorite cleaner using an old paint brush helps.

Sounds good, I'll do that and put new fluid in and filter and report back next weekend.
Thanks for the help, this has been a great site, and I've gotten a lot more info than I though I would've in just a few hours.
Thanks everyone
:American Flag 1:

We're pretty quick on the draw around here. Doesn't usually take long to get an answer. :biggrin2:

Welcome aboard!

Welcome to the madness.:beerchug:
Just a word of causion. Jonathan can verify this... If you're using paper towel to clean out the diff, make sure you leave nothing behind... Acctually it would be best to use rags instead to avoid chances of any toweling left behind.
I did this awhile back on one of my 125's and a small piece was left behind and sucked up into the suction tube. I assembled everything, new Hytran and took off with the tractor only to stop part way down the driveway...
Had to drain the fluid to find the problem. Anyway long story long, use cloth rags to clean out the diff.:biggrin2:

I would pull the rear diff. cover off as well as the top diff. cover.
Then pull out all that jellied crap inside.
Rags, bare hands, etc.

When I did it on my 127, I also used an air compressor with a blow gun that I could shove a piece of bendable copper tube onto.
From above, I could get in ahead/behind of the ring gear and into the diff. assembly and blow that jellied crap out the rear.
Get a good size cardboard box and lay it down and anchor it facing the rear end so the flying crap has a better place to go than all over the shop floor.