763 Drive motor seal

[Tazza]

Well I spoke too soon. After using it for about an hour yesterday my original leak that I started with returned. There is a steady stream running from the drive motor. As you look at the motor installed, there is the end plate that has all of the hydraulic hoses to it. The leak is coming from between that plate and the next plate right about where there is a "shuttle valve". There is a pipe plug that takes an allen wrench to take off. What is this and what does it do? I left this in when I rebuilt the pump. I did not notice any cracks or anything unusual in this area when it was apart. I cleaned the filter located in the hydraulic line that has the aluminum filter houseing, so that should not be building up pressure.

The shuttle valve plugs the high pressure area when the motor is working and allowing the low pressure leakage to go back to the tank as far as i understand the system. You could have a hair line crack in the geroler or end plate? if you replaced the seals, there is no reason for it to leak again....

 

[crazycat]

The shuttle valve plugs the high pressure area when the motor is working and allowing the low pressure leakage to go back to the tank as far as i understand the system. You could have a hair line crack in the geroler or end plate? if you replaced the seals, there is no reason for it to leak again....

Is there anything else that I may be missing that would build up too much pressure? Would the spin on hydraulic filter make the system do this? This is one filter I have not changed out yet since I bought it. I will probably pull out the shuttle valve and clean it first too. I just hate to pull that thing back out again if I am missing something. Do they sell the plates seperately If one of them has a hairline crack?

 

[Tazza]

Is there anything else that I may be missing that would build up too much pressure? Would the spin on hydraulic filter make the system do this? This is one filter I have not changed out yet since I bought it. I will probably pull out the shuttle valve and clean it first too. I just hate to pull that thing back out again if I am missing something. Do they sell the plates seperately If one of them has a hairline crack?

I can't see the shuttle valve being the problem.
The plates are available, if its a crack in the geroler you will need that entire segment, same with the end plate. Have you talked to the people at http://loaderpartssource.com/ ? give them details of what its doing, they know their stuff and have the parts to repair it available too.

 

[crazycat]

I can't see the shuttle valve being the problem.
The plates are available, if its a crack in the geroler you will need that entire segment, same with the end plate. Have you talked to the people at http://loaderpartssource.com/ ? give them details of what its doing, they know their stuff and have the parts to repair it available too.

Well, I finally got time to pull the drive motor back off and apart. The O-rings all were in place and looked good. I put a straight edge on some of the surface areas and they appear to be slightly warped. Can these plates be surfaced at a machine shop? I have a buddy with a shop, but I am not sure if this can be done. A reman motor from the website you gave me is $798. Any suggestions? Thanks

 

[Tazza]

Well, I finally got time to pull the drive motor back off and apart. The O-rings all were in place and looked good. I put a straight edge on some of the surface areas and they appear to be slightly warped. Can these plates be surfaced at a machine shop? I have a buddy with a shop, but I am not sure if this can be done. A reman motor from the website you gave me is $798. Any suggestions? Thanks

I believe the O rings would have taken up that small amount of warp. The only parts you can flat palte are the end plates NOT the geroler (the part that the rollers fit in).
Just how warped are they?

 

[crazycat]

I believe the O rings would have taken up that small amount of warp. The only parts you can flat palte are the end plates NOT the geroler (the part that the rollers fit in).
Just how warped are they?

It was definately visible. I have ru out of time to mess with it so I ordered a reman one from the site that you posted. Roughly $800. I feel like I wasted some money messing with it, but I learned a lot about the machine. Thanks for all of the input.

 

[Rio]

The motor carrier is the big cast part that bolts to the chain case, it also has the drive motor that bounts to it. With the drive motor off, you should see a large seal, about 4-5" diameter with a weird step in it. The one that seals the face of the motor, if it was leaking, yuou'd have oil on the ground. As the oil is going to the chain case, this seal is holding up just fine.
Did you check the case drain filters? the alloy things that are connected to the case drain ports of the motors (small hoses). If they get plugged, the case drain pressure will increase and push past the seal.
Does that make any sense?
If you grab a manual, look at the chain case area, it will make sense when you can see the pictures.

My S595 Does not have the case drain filters. Instead it's a manifold and schematics do not indicate any case drain filter. My oil is pushing past the seal. The 1st time my bring seal was blown. Now it's leaking but all seals appear to be perfect. There's only 2 hours on it since I replaced new seals.

 

[Tazza]

It was definately visible. I have ru out of time to mess with it so I ordered a reman one from the site that you posted. Roughly $800. I feel like I wasted some money messing with it, but I learned a lot about the machine. Thanks for all of the input.

At least it will fix the issue, shame it cost you a lot of time and a seal kit, but we all learn. You will have parts if you ever need them i guess.