Bobcat 751 chain case leak

[operatorexmark]

I've been lurking on this forum for a while now and have successfully repaired a leaking wheel motor on my 743 from reading through threads, but this 751 has me stumped. This is a 751C one of the earlier 514 serial #s with the 4 bolt wheel motor. Initially when I got the machine it would lose the entire contents of the reservoir after 5 min of driving and leak out the top of the chain case. I replaced the case drain filters on both sides, both had bits of black plastic/rubber debris the right side had more than the left. the filters weren't packed just maybe a pinch of rubber particles. I replaced the left side motor carrier seal, It already had a one piece seal in it and it looked like it was in good condition- no tears around the lips. I figured I might have just had clogged case drain filters, so before replacing the right carrier seal I filled it back up with fluid and drove it for 10 minutes. Again I have fluid leaking out of the chain case. What I don't understand is why I don't leak fluid when I remove the drive motor? I loosened the drive motor mounting bolts on both sides enough to crack the motors 1/8" from the carrier housing. There was still enough pressure in the chain case that fluid was leaking out of the top cover, but if one or both drive motors are leaking, shouldn't some excess fluid seep out when I pull the drive motor? I'm not sure how I'm going to pull the right side motor because I don't have clearance to get to the hoses so I'd like to be sure that it's carrier seal is leaking. I have decent power to the wheel motors, but should I reseal them as well?

 

[zoneage1]

I've been lurking on this forum for a while now and have successfully repaired a leaking wheel motor on my 743 from reading through threads, but this 751 has me stumped. This is a 751C one of the earlier 514 serial #s with the 4 bolt wheel motor. Initially when I got the machine it would lose the entire contents of the reservoir after 5 min of driving and leak out the top of the chain case. I replaced the case drain filters on both sides, both had bits of black plastic/rubber debris the right side had more than the left. the filters weren't packed just maybe a pinch of rubber particles. I replaced the left side motor carrier seal, It already had a one piece seal in it and it looked like it was in good condition- no tears around the lips. I figured I might have just had clogged case drain filters, so before replacing the right carrier seal I filled it back up with fluid and drove it for 10 minutes. Again I have fluid leaking out of the chain case. What I don't understand is why I don't leak fluid when I remove the drive motor? I loosened the drive motor mounting bolts on both sides enough to crack the motors 1/8" from the carrier housing. There was still enough pressure in the chain case that fluid was leaking out of the top cover, but if one or both drive motors are leaking, shouldn't some excess fluid seep out when I pull the drive motor? I'm not sure how I'm going to pull the right side motor because I don't have clearance to get to the hoses so I'd like to be sure that it's carrier seal is leaking. I have decent power to the wheel motors, but should I reseal them as well?

Hi! I know this was from a couple years ago! But I am having a similar issue! I have fluid coming out of the top of the chaincase past the seal. Did you ever find a solution? Any help would be great! Thank you!!

 

[Tazza]

No need to re-seal the motors, the seals are for high pressure to the geroler, it will not fix your issue.So, you had fluid coming out the chain case even with the motors spaced away from the carrier 1/8" That doesn't sound right at all.
If there is play in the shaft the seal runs on, this can allow fluid in past the seal too.
If you can T in a pressure gauge to the small line, see what pressure you're getting, just in case there is a blockage further up. The issue is, without a load on the motors, you won't get a whole lot of case drain fluid coming out.