To split the tractor, aside from all the wiring, hydraulic lines, and obvious mechanical assemblies, the propeller shaft must also be disconnected. There is a housing that slides off after removing a single bolt at each end. Removal of a spring pin allows the coupler to slide off the shaft. Just a 8 bolts between the engine case and clutch housing.
Into the garage with the HST unit. Picture 3 is of the "plugs" where the oil was noted dripping from several posts back. Pulled and inspected them. The o-rings seem fine.
Next I removed the top plate to the precharge pump (seen in the zip lock bag). The gyrotor was really hard to remove with the oil still present. I ended up pulling just the center section then it was much easier. There does appear to be some very minor wear on the swash plate underneath shown in the first picture. The tractor has 540 hours on it and is a 2009.
The four pictures attached are of the HST case, 1 before splitting and the other three showing the interior components. The arrow shows the ruptured / failed seal.
Not sure what the gasket material is? Seems very paper like. Question is what caused it to fail? Seems like the logical next step is to pull apart the RV on the HST and inspect it.
Since I have it apart, I may consider rebuilding the entire unit if parts can be sourced. In the interim I'll look to get all new seals and o-rings at a minimum. The o-rings seem very stiff (high durometer) in general. Not sure what material they are either.
OK so this is the current state of the tractor. I'll certainly need to source parts to remedy the issue. Question is should I go further to seek the out the possible source of the gasket material found earlier in the primary hydraulic oil filter. Also trying to decide the best means of cleaning the oil off parts and where to get parts. Michigan Iron seems to have a decent website though the parts diagrams are a bit of a chore to muddle through. Some of the parts are clearly different with the Bobcat (and years / model for Kioti). I'll need to call and confirm if the online parts tool is for even the same model HST as in this machine.
It looks like it was sucked inward, or pushed there during assembly. You may be able to replace it with a more reliable sealant instead of a gasket. If that does not cause any clearance issues. I use sealants where I can.
There may not be much you can buy to rebuild your HST. Pump and motor may be sold as assemblies, but more likely, you would have to buy the whole HST for thousands of $. Those O-rings may be replaceable, and shaft seals, too. You can buy those by size from aftermarket suppliers.
Thanks for posting. Sorry you have to work outside.
A hi-quality silicone works well, but you have to make sure that replacing your OEM fibre gasket does not cause any clearance issues if replaced with a thinner gasket. It was not an issue for the other HSTs I have rebuilt.
I will PM you about a possible visit, if you are willing to show me your HST. I have not been inside any of these DaeDong units.
