DIY Snow Plow on a Cat 262D Skid Steer: Leaking flat connector.

[lankyyankee]

Howdy Forum,
I've been dealing with a nagging problem I just can't seem to solve.

Background: I recently got a great deal on an old 7 foot Western pick up truck snow plow that I've mounted to a quick attachment plate that I'm using on my Cat 262D skid steer. Like most pickup truck plows, it has two single acting hydraulic cylinders. They are made for ~5 GPM not the 25GPM that comes from my tractor, so I made some 1/16th inch restrictors (pictured below) and also installed a cross relief valve for impact protection.

Here is a picture of the restrictors I made prior to drilling the 1/16th inch holes. The dimples are to prevent the aluminum from backing out.

Basically, I followed this guy's work:
http://rodnh.byethost12.com/bobcat/bobcatplow.htm?i=1

My hydraulics layout is similar to the above website:

My Cross relief valve:
1/2 NPT 3 GPM 15-3 PSI HYD CUSHION VALVE


The problem: The blade moves left and right as expected, when I roll the hydraulic thumb switch on the cat forward and aft, but the problem is, I can't for the life of me, get the bottom flat connector to stop leaking hydraulic fluid. I've swapped out both FEM flat connectors on the plow and on the tractor but that didn't help. I connected the plow to my neighbors Mustang skid steer and it leaks on his flat connectors too. Since it's leaking on both tractors, neither of which leak with other attachments, this leads me to believe it's an issue with the plow hydraulics. I must be missing something in my design. Any ideas?

Much Appreciated!
-LY

Here's a video of the offending connector. Not a huge leak ,but enough to make a mess over an hour's worth of plowing.

 

[Todd727]

Do other attachments leak on that port?

 

[lankyyankee]

Do other attachments leak on that port?

Can't say for sure, because I don't have another attachment that requires the aux hydraulics. But like I mentioned, I took the plow to my neighbors and it leaked on his Mustang skidder too. He runs other brush cutter attachments and they don't leak, so I assume it's the plow.

Plus, I've replaced both ends of the coupler on the tractor and on the plow side. Since they are new couplers, I'm wondering if I'm not in some over-pressure situation?

 

[Todd727]

Shouldn't be. You can buy flow restrictors, both fixed and adjustable like seen in you link at Northern Tool or at a Parker Hydraulic store. Are you sure that the flat face couplers on the skidsteer and the plow are exactly the same? There are some flat faced connectors that are just a bit different. I've also found that there are some manufacturers that don't work well together. I've had good luck with Faster and Parker. I've attached literature from Parker for their FEM and FEC connectors.

 

[lankyyankee]

Shouldn't be. You can buy flow restrictors, both fixed and adjustable like seen in you link at Northern Tool or at a Parker Hydraulic store. Are you sure that the flat face couplers on the skidsteer and the plow are exactly the same? There are some flat faced connectors that are just a bit different. I've also found that there are some manufacturers that don't work well together. I've had good luck with Faster and Parker. I've attached literature from Parker for their FEM and FEC connectors.

I ran through my setup with the local Cat dealer. They were very helpful! Todd, they came the same consensus regarding matching connectors as you suggested above. Even though it's the proper FEM connector on the plow side, it isn't a Cat connector. So I'm going to try matching brands. If it works, I'll mic the two offending male ends and report if there is a significant difference in measurements.

 

[Todd727]

I had an issue with an FF series connector not working with the FEM series. Hope you get it worked out.

 

[lankyyankee]

RESOLVED! While the Fleet Farm FEM connectors fit the CAT skid steer, it was not the right connector. After installing CAT brand flat connectors, I have no more leaks! Lesson learned, I have to go with cat brand connectors, I mic'ed the male flat connectors from the different brands and they are slightly different diameters and taper.

The new CAT brand connectors also play well with my neighbors Mustang skidder, so I don't think this fitment is limited to only Cat machines.
Thanks ya'll.
-LY

 

[Todd727]

I bet Parker or Faster connectors would work too. The cheap ones from places such as TSC and Fleet Farm are just that, cheap.

Glad you got it working. Nice unit.