Hydraulic Question

[BobMac59]

I have a Bobcat 753 with a problem that is driving me crazy. I am pretty mechanical capable but dont know crap about hydraulic systems.
I filled the hydraulic tank to within the marks on the stick. the next day I go in the garage and there is oil all over the floor. The oil is coming out of the red button on top of the frame where there is a plate bolted to it. Right under the seat… and the tank is empty!
Can someone please tell me why all the hydraulic fluid is draining into there then out of the top? Thank you

 

[brdgbldr]

I have a Bobcat 753 with a problem that is driving me crazy. I am pretty mechanical capable but dont know crap about hydraulic systems.
I filled the hydraulic tank to within the marks on the stick. the next day I go in the garage and there is oil all over the floor. The oil is coming out of the red button on top of the frame where there is a plate bolted to it. Right under the seat… and the tank is empty!
Can someone please tell me why all the hydraulic fluid is draining into there then out of the top? Thank you

It appears that your motor carrier seals are bad. When they go bad the oil from the hydraulic system leaks into the chain case.

You can verify this by checking the chain case oil level. Just know that if you check it from the plug at the front of the machine, oil is going to gush out like a garden hose on full blast. Be ready for at least 10 extra gallons to come out. Could be way more.

Here is a link to the parts catalog. The schematics can help you locate the seals:
https://partscatalog.bobcat.com/

 

[BobMac59]

oh Man that makes sense. I will definitely check that out, now that you said that it has to be the only way that the oil is going in there. I know damn well that chaincase is full because its cominv right out of the vent!!
Thank you so much, I had NO IDEA

 

[BobMac59]

I was just wondering. I was finding no videos of changing these seals on the 753. Are you familiar with this job? Do the chains and sorckets have to be removed to replace these seals or are they replaceable from the outside by just removing the drive motor ?

 

[brdgbldr]

I was just wondering. I was finding no videos of changing these seals on the 753. Are you familiar with this job? Do the chains and sorckets have to be removed to replace these seals or are they replaceable from the outside by just removing the drive motor ?

You just need to remove the motor.

Look at the parts catalog schematic and look at the “Motor Carrier”. The exploded view shows the seal. Make sure you clean arround the motor really well and have caps and plugs for the hoses and ports. Do not let any dirt get in the motors.

When I did mine on my 742 I made a tool to seat the seal from an ABS pipe coupler with a plug in one end to hammer on.

 

[brdgbldr]

I was just wondering. I was finding no videos of changing these seals on the 753. Are you familiar with this job? Do the chains and sorckets have to be removed to replace these seals or are they replaceable from the outside by just removing the drive motor ?

Here is a video I found. Not the best but it gives you the idea:

 

[BobMac59]

Awesome ! Thank you so much. I have been stressing over this for about a week. I have been a member of this forum for anbout 24 hours and you gave gave me all the answers . Thank you so much !

 

[wateka]

I have a Bobcat 753 with a problem that is driving me crazy. I am pretty mechanical capable but dont know crap about hydraulic systems.
I filled the hydraulic tank to within the marks on the stick. the next day I go in the garage and there is oil all over the floor. The oil is coming out of the red button on top of the frame where there is a plate bolted to it. Right under the seat… and the tank is empty!
Can someone please tell me why all the hydraulic fluid is draining into there then out of the top? Thank you

I thought this was a button too when I started working on my 853. Turns out it’s an air vent and there’s another one on a tube coming off my cooling fan housing.

 

[KyMadMan]

It appears that your motor carrier seals are bad. When they go bad the oil from the hydraulic system leaks into the chain case.

You can verify this by checking the chain case oil level. Just know that if you check it from the plug at the front of the machine, oil is going to gush out like a garden hose on full blast. Be ready for at least 10 extra gallons to come out. Could be way more.

Here is a link to the parts catalog. The schematics can help you locate the seals:
https://partscatalog.bobcat.com/

I am ass u ming that the chain case needs to be drained BEFORE you remove the drive motors? The FSM doesn't make mention and I would think that if the fluid from the drive motor is getting in, it will also come out once the motor is removed.

 

[brdgbldr]

I am ass u ming that the chain case needs to be drained BEFORE you remove the drive motors? The FSM doesn't make mention and I would think that if the fluid from the drive motor is getting in, it will also come out once the motor is removed.

When I did mine the oil was at the proper level and none came out. If I remember correctly the oil in the chain case is normally below the level of the motors. You can check this by looking at the height of the bottom of inspection plug on the front of the machine and comparing it to the motor height.

 

[KyMadMan]

When I did mine the oil was at the proper level and none came out. If I remember correctly the oil in the chain case is normally below the level of the motors. You can check this by looking at the height of the bottom of inspection plug on the front of the machine and comparing it to the motor height.

Thanks for your information on this. Since I too have fluid coming out of the vent I'm sure I'll have to drain many gallons to get it to the correct level, THEN I'll remove the drive motors!