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Message: <blockquote data-quote="bttpe" data-source="post: 116624" data-attributes="member: 19457"><p>This is a problem I've had on both a 753 and now a 763 that I have never resolved. The hydraulic oil just completely dumps into the chaincase in a matter of minutes. I've literally gone through 60 gallons of oil on these two machines and have not resolved the problem. I'm going to work through it until I've completely solved it and then post a video on Youtube and a thread on any site / forum. Here is what I understand. The carrier seal separates the drive motor from the chain case and is prone to failure. I've both carefully slipped the seal over the shaft and then drove it home as well as just used a tool to drive it home. I had our local Bobcat Service Center install them and they simply drove them in using a welded pipe with a rod. They didn't take any special care on the shaft side although they did ruin one while doing this and had to replace it. Now is just a list of things we have tried. 1. Check the hex bolt inside the bearing shaft to make sure it is tight and not allowing fluid transfer. 2. R&R both motors looking for major scoring or damage to the geroller assembly and reseal with kit. Some threads tell us that if the the gerollers aren't tight that they have failed. I doubt that is exactly correct. It would seem to me that some leakage would be normal wear (could be wrong). However, scoring from debri would be a definite bad sign. 3. Check bearing shaft on chaincase side for movement. Looking for no more than 0.001" Should be tight like a new bearing. Otherwise must replace that bearing inside the chain case (big job) 4. Removed all inline hydraulic filters. These are the small bronze looking filters. We just removed them to verify good flow through the lines. 5. We don't have a way to measure flow for "case drain". For those who don't know some hydraulic oil will bypass or leak through the geroller assembly and go into the cavity between the motor and the side of the chain case. With the machine not moving there is almost always zero leakage. Once you try to move the Bobcat forward or backward you will see oil come out of that case drain. I don't know what is acceptable vs not acceptable. I can tell you that we ran the engine/hydrostat and motors out of the Bobcat and never saw case drain. However now that it is installed there is steady stream (don't know pressure or flow yet). 6. One of the case drains is directly connected to the case drain on the hydro pump. We question if this "fights" each other and builds pressure causing a carrier seal failure. The only way I can see to determine this is if we completely drain the chain case and look down at a new seal to see if it is pushing through. We have not done that yet. All we know to do is to repeat this entire procedure. If anyone sees something we are doing wrong let us know. Remember I'm documenting this so i can help others. If you can weigh in or persuade a Bobcat Tech to weigh in please do it so we can document a solution. Special thanks to this site: https://www.youtube.com/watch?v=koXFbOd0BKc He's trying to help and I recommend his site. The more subsribers he gets the more likely he'll continue to post helpful videos. Please help if you can.</p></blockquote><p></p>

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