Adding a case drain to skid steer

[GaryBDavis]

Finally made the move to a skid steer for brush work around the farm and I need to run a shredder with it. This will be one of those mulching type shredders used to clear underbrush. The newer ones use a piston pump that requires a case drain even though it's a standard flow unit (~20GPM).

My skid steer is a 2011 CAT 279C and just has the standard flow hydraulics with no case drain. The high flow version of this machine comes with a case drain coupler. My plan is to get the case drain coupler and steel line from CAT and then plumb it directly to the tank. I don't want to hack into the factory hydraulic lines. I'll modify my coupler bracket on the loader arm to hold the case drain coupler.

My remaining issue is how to put a fitting on the plastic hydraulic tank. My current thought is to use one of those grommet type hose barbs. You drill a 1/2" hole in the tank, insert the grommet and press in the steel fitting that has a 1/4" right angle hose barb on it. It uses a compression effect to make a leak proof seal (the barb inserted into the grommet has an flared end). These are for fuel tanks so it will handle the hydraulic oil. My only concern is how to drill the hole into the tank. I'm not sure how to keep the plastic shavings out of the oil tank. I know most folks would probably just drill it and not worry about it. There's probably a strainer at the pump intake that will catch any pieces. The pump probably wouldn't bat an eye at a small plastic shaving anyway.

Looking for thoughts/recommendations of anyone who might have done something like this already.

Thanks,
Gary

 

[IceStationZebra]

I would be realy suprised if they have different resevoirs for std flow vs high. See if you can find a parts diagram and figure out where the factory line goes. ISZ

 

[GaryBDavis]

They use the same tank but the pumps are different. The high flow pump has a case drain port but the standard flow does not. I talked with CAT technical services. They were helpful and sent me diagrams, but there is no factory case drain for the standard flow, so I have to do it on my own.

 

[oldnslo]

Your HST drive pumps and possibly also the motors would have a case drain line. Can you tee into that line?

 

[GaryBDavis]

I can see at least one place where the is a low pressure line at the pump. It goes to some other hydraulic device (spooler, valve, etc.). There is an elbow that I could replace with a T, but I'm hesitant to do that since it doesn't go directly to the tank. I really don't want to hijack the hydraulic lines. The only concern I have left with my current plan is to figure out a way to keep the shavings out of the plastic tank when I drill the 1/2" hole.

 

[ciderman]

Pack the drill flutes with grease and have the shop-vac running?

 

[GaryBDavis]

That might work. What do you think will happen if I get a plastic shaving or two in the tank? Assuming there isn't a screen filter on the pump intake, I think the pump would turn it into mush with no damage?

 

[ciderman]

There will be a strainer in the tank, it's a requirement for any top end hydraulic system and CAT is top end. One other thing you could do is plumb in an air regulator and pressurize the tank to no more than 3 psi. Debris would be blown out while drilling.

 

[GaryBDavis]

There will be a strainer in the tank, it's a requirement for any top end hydraulic system and CAT is top end. One other thing you could do is plumb in an air regulator and pressurize the tank to no more than 3 psi. Debris would be blown out while drilling.

Another good idea. Not sure I have a regulator that is that precise although I'm sure they make them. There is a fill cap and a filtered vent cap that I will have to deal with. The vent cap is threaded. But at 3PSI, I can probably hold that back by hand pressure along with a piece of film wrap and a rag.

 

[IceStationZebra]

According to this training material I found it shows a case drain on the main pumps. It doesn't show where it goes but you should be able to follow it. See page 51. ISZ
http://faculty.riohondo.edu/jfrala/BC CAT BOOK/SERV1833_TXTCskidsteer.pdf

 

[GaryBDavis]

According to this training material I found it shows a case drain on the main pumps. It doesn't show where it goes but you should be able to follow it. See page 51. ISZ
http://faculty.riohondo.edu/jfrala/BC CAT BOOK/SERV1833_TXTCskidsteer.pdf

I've seen that publication. I need to raise the cab and compare that pump to mine. That may be the high flow version. Either way, why would the put case drain ports on the pump and not hook anything to them? Maybe it's a pump model that can be used in several different applications so those ports are not used for this application. Also, are they case drains that are meant to be hooked to a tank? If so, they may not allow flow back to the tank but are meant for the pump to drain to the tank.

Not being sure, it would be safer to drain directly back to the hydraulic tank.

 

[IceStationZebra]

What I meant was that you could follow that line back to see where it drains to. Almost all piston pumps have a case drain to handle the oil that slips past the moving parts. As I recall the pumps shown in the picture are the travel pumps (and it looks like they share a drain). It is certainly possible to put a return in the plastic tank, but if one already exists you wouldnt have to risk getting particles in the system or leaking. ISZ

 

[rkass]

Finally made the move to a skid steer for brush work around the farm and I need to run a shredder with it. This will be one of those mulching type shredders used to clear underbrush. The newer ones use a piston pump that requires a case drain even though it's a standard flow unit (~20GPM).

My skid steer is a 2011 CAT 279C and just has the standard flow hydraulics with no case drain. The high flow version of this machine comes with a case drain coupler. My plan is to get the case drain coupler and steel line from CAT and then plumb it directly to the tank. I don't want to hack into the factory hydraulic lines. I'll modify my coupler bracket on the loader arm to hold the case drain coupler.

My remaining issue is how to put a fitting on the plastic hydraulic tank. My current thought is to use one of those grommet type hose barbs. You drill a 1/2" hole in the tank, insert the grommet and press in the steel fitting that has a 1/4" right angle hose barb on it. It uses a compression effect to make a leak proof seal (the barb inserted into the grommet has an flared end). These are for fuel tanks so it will handle the hydraulic oil. My only concern is how to drill the hole into the tank. I'm not sure how to keep the plastic shavings out of the oil tank. I know most folks would probably just drill it and not worry about it. There's probably a strainer at the pump intake that will catch any pieces. The pump probably wouldn't bat an eye at a small plastic shaving anyway.

Looking for thoughts/recommendations of anyone who might have done something like this already.

Thanks,
Gary

Hey Gary,

How did this end up working out? I'm needing to do the same thing. How did you attach the barbed fitting to the hydraulic line? Any pictures or information would be really appreciated!