loosing a major amount of hydraulic fluid... but can not see where..

[cadillacderek]

I have a 742 with the gas engine. I was running my back hoe attatchment and all the sudden it started getting jerky and slower. I stopped it and checked the fluid and it was very low so I filled it back up and and went back to digging and it did ok for about 2 minutes and then empty again? filled it back up and same thing a few minuts later.. I went through almost 10 gallons of fluid and it just keeps dissapearing so i lifted the cab to look for leaks and could not see any.. no puddles under the machine, and didnt see any fresh fluid in the bottom of the engine compartment either. Now In my opinion thats an awfull lot of fluid to loose in a short period of time with absolutly no puddles or visual leaks?? I decided to pressure wash it off so i could hopefully see where it is leaking after it dried out. the next day I added some more fluid, started it, and still couldnt see where it was leaking.. So I let it sit for a week or so and its finally its dripping fluid out of the rear axel shafts?? anyone have any ideas?? im confused? also another weird thing is, after the engine is off and i move my right lever over to the accsesory postion i can hear some gurgling and bubbling noise in the hydraulic fluid tank.. like its burping air out or something ..and it only makes this noise when i move the stick into the acc. postion is this normal? i never notived before? any help is greatly appreciated thanks

 

[jerry]

Take the pipe plug out of the front center of the chain case but have a oil drain pan there first as that is where your ten gallons is and it will come out when you remove the plug. leaky seals on drive motor so search this forum for drive motor seal replacement threads.

 

[Tazza]

Take the pipe plug out of the front center of the chain case but have a oil drain pan there first as that is where your ten gallons is and it will come out when you remove the plug. leaky seals on drive motor so search this forum for drive motor seal replacement threads.

Jerry has it, no external leaks, its in the chain case. There are seals between the drive motor and chain case, if they are bad, it will pump oil into the chain case till its so full, it will squirt it out the axle seals, as you have found out.

 

[cadillacderek]

Jerry has it, no external leaks, its in the chain case. There are seals between the drive motor and chain case, if they are bad, it will pump oil into the chain case till its so full, it will squirt it out the axle seals, as you have found out.

ahhh..ok.. thats makes total sense, i have been searching the forum for drive motor seal replacement and only found a few threads.. but nothing in detail .. i did find a manual that somone posted online but its pictures are limited and it just shows how to take the drive motors out but nothing about the seals? are these seals that need to be changed located in the motor itself or the chain case? or are they simply smashed in between the 2 when you mount the motor? any links to help would be great help.... also, thanks for the prompt replys guys!!

 

[Tazza]

ahhh..ok.. thats makes total sense, i have been searching the forum for drive motor seal replacement and only found a few threads.. but nothing in detail .. i did find a manual that somone posted online but its pictures are limited and it just shows how to take the drive motors out but nothing about the seals? are these seals that need to be changed located in the motor itself or the chain case? or are they simply smashed in between the 2 when you mount the motor? any links to help would be great help.... also, thanks for the prompt replys guys!!

I believe the seals are on the chain case its self. Its been a while since i did this though. There is also an O ring in the drive motor where the shaft comes out. Its on the inside of where the shaft is, you can get it out without pulling the motor apart. I think its a brass housing/bushing, but don't quote me on that.
If you remove the drive motors, you will see what i mean.