Location of bypass valve on Hydro-Gear 350-0510 transaxle

A

AdvisingElf

Member
I've worked on cars and trucks a lot, but not much on lawnmowers. I am fixing up an old Cub Cadet LT1046, and I drained and re-filled the transaxle. I didn't know about needing to purge the air until I talked to my small engine mechanic friend. I've searched for the location of the bypass valve online, but couldn't find anything. It isn't shown in any of the diagrams I found, or even in the service manual that describes how to do the purging.

Any help would be appreciated.
 
StarTech said:
Should be in front the RH axle housing just below the brake caliper.

View attachment 73257
Click to expand...
I'm not trying to be a smart @$$, but that says "arm," not "valve." That's the arm that moves when you pull the rod at the back to allow the wheels to turn freely so you can push the mower around.

The service manual says: "With the bypass valve open and the engine running, slowly move the directional control in both forward and reverse directions (5 to 6 times)..." My mechanic friend said the valve needs to be open for the air to be released. He's not familiar with this model that old, so he doesn't know where it's located.

ETA: If the procedure is to move the bypass arm, then there's no reason to jack the mower up off it's wheels to do the purging. The wheels shouldn't turn.
 
Last edited:
BTW, the service manual I have is for a 310-0510, not a 350-0510. it is obviously different, because my unit has a drain plug, and the 310 does not because the service manual says to take the unit completely out and turn it over to drain it out of the fill hole. Even the Hydo-Gear website doesn't have a manual for it.
 
The manual is the correct one per Hydro Gear dealer site. The manual assumes the tech has enough sense to know it doesn't cover all variations of the 300 series. It just covers the basics.

The bypass arm attaches to the internal lever to open both the forward and reverse valves which BTW are inside the filter; therefore, puts the unit in bypass mode. The reason getting the wheels off the ground is in case one of the two bypass valves doesn't open and I have see that. Plus you want the pump motors, especially the wheel motor, to turn a little to clear out the air in them. They will turn when the wheels are off the ground in bypass mode most times.

1778353128240.png
1778353084339.png

Also particular model does has a drain plug so it doesn't have to be removed in order to change the oil; unless, you can't access the fill port. When ones without drain plugs are serviced it can be added for later use but requires opening up the unit to keep the metal shavings removed while drilling and tapping the hole.

618-04269 superseded to 618-04269A

1778352486284.png
1778352852556.png
 
I really appreciate your help.

While we're at it, I assume you can't change the filter without disassembling the whole unit.
 
AdvisingElf said:
I really appreciate your help.

While we're at it, I assume you can't change the filter without disassembling the whole unit.
Click to expand...
Right. As the center section has to be remove. BTW the filter is just a nylon screen type so it just keeps out the metal flakes.
 
You must log in or register to reply here.
Back
Top