hydraulic - front end loader question

[cypressfarms]

I have an older Ford 6710 with a front end loader. The tractor was made in Canada. It has a joystick to operate the front end loader. Four lines A1,A2,B1 and B2 come down from the joystick to a transfer box then go from the transfer box to the front hydraulic cylinders. It leaks badly. I've had it "rebuilt" twice ($300 a pop), and now the tractor repair guy I use tells me that I need a new transfer box ($1,000). NO way can I afford $1,000. The loader is a Buhler Allied 595, but the transfer box reads "Parker Mobile Hydraulics" with a bunch of serial #'s. Can these be bought used/rebuilt? Does anyone have any experience with these tranfer boxes? I spent a good bit of time under the tractor yesterday and it seems like I should be able to replace this myself. 4 lines in, 4 lines out. I'm leaving dead spots in my pastures now :nod:

Any comments?

 

[tom4018]

Not sure what you call a transfer box. But you should be able to get a universal type valve to work on there, would have to fab up a bracket for mounting.

 

[cypressfarms]

Not sure what you call a transfer box. But you should be able to get a universal type valve to work on there, would have to fab up a bracket for mounting.

There is a square box bolted to the lower support bracket for the front end loader just below my cab. It takes the lines from the joystick and "transfers" them to the hydraulic cylinders on the tractor. Maybe some type of pressure relief system? I know that it's mostly o-rings, and the two previous times it's been rebuilt they replaced the o-rings. It now shoots out hyd, fluid when I operate the loader.

I'll try to post a pic of it.

 

[cypressfarms]

Here's a couple of pics of the "box" in question.

 

[upfrombottom]

I have a similar rig on one of my tractors, and as you said it is nothing but some o-rings. If the case is not cracked, or the adaptors that the lines are attached to haven't been cross-threaded, you could easily fix it yourself. When your replacing the o-rings, be sure to go to a tractor dealer, or a good parts store to get the rings. You might as well buy a bag of rubber bands if your going to use Japan made o-rings. I would also check and re-tighten the lines after i ran it a while and heated everything up.

From the picture its hard to tell, but from the patern of the oil, it looks like one of the quick-connects, maybe what is leaking. Have someone watch for the leak while you operate the loader.

 

[cfpinz]

You need a different mechanic.

Isolate the leak(s) and put the correct seals in it. Looks like the two upper front hoses are leaking.

 

[ChrisB]

I'm not a mechanic by any stretch of the imagination so this may be a dumb comment. But I don't understand what the transfer box does. Can you just put quick disconnect fittings on the lines going from the transfer box and plug those fittings into the lines from your joystick? Eliminate the transfer box altogether?

 

[cypressfarms]

I'm not a mechanic by any stretch of the imagination so this may be a dumb comment. But I don't understand what the transfer box does. Can you just put quick disconnect fittings on the lines going from the transfer box and plug those fittings into the lines from your joystick? Eliminate the transfer box altogether?

I think it's some kind of pressure relief system, but heck if I know.

 

[cfpinz]

It's not a transfer box, it's a remotely controlled two spool loader control valve. They can either be controlled by a cable or a smaller hydraulic control circuit, or electronically if you want to spend big bucks. Same thing as the regular loader control valve on an open station tractor but controlled remotely. Clear as mud?

Yours looks to have two cable controls coming in the rear center of the valve. Usually, there's 4 work ports going to your loader. Two input ports coming from the tractor remotes or other source. On occasion, there will be another dump port for a power beyond type setup that dumps excess fluid back in the sump.

 

[Judge Sharpe]

Take it off and take it to a hydraulic repain shop and have them look at it. they can tel you if the line fittings are leaking or the valve it self. If it is the fittings replace them all, maybe get new hoses, if it is on the box, I believe you can change the adapters that the quick connects screw into. Or go on line find the company and talk to them.
Bill Brower

 

[lavacarancher]

It's not a transfer box, it's a remotely controlled two spool loader control valve. They can either be controlled by a cable or a smaller hydraulic control circuit, or electronically if you want to spend big bucks. Same thing as the regular loader control valve on an open station tractor but controlled remotely. Clear as mud?

Yours looks to have two cable controls coming in the rear center of the valve. Usually, there's 4 work ports going to your loader. Two input ports coming from the tractor remotes or other source. On occasion, there will be another dump port for a power beyond type setup that dumps excess fluid back in the sump.

CF is right on the money. This "box" converts the movement of the joystick cables to valve movement. The valves in turn direct the hydraulic pressure to the appropriate cylinders.

There is nothing external to this valve assembly that could leak except a few O-rings - unless the case is cracked. Carefully remove the hoses (mark them where they go), remove the hose to pipe thread adapters that screw into the controller and remove the O-rings between the adapters and the case. Try to get them off in one piece. There may also be back-up rings in the gland but I doubt it. I think this application is a surface seal type and not a rod seal gland. Take the O-rings to a real, honest-to-God hydraulic shop and get them to size the O-rings and replace them. Use Parker or Parco O-rings, FEP, 90 durometer, only. You can probably get O-rings from your local tractor place or hardware store but then you will be doing this all over again in a couple of months. Your talking about $10 worth of good O-rings or $2 worth of junk O-rings.

I almost forgot. Get the hydraulic shop to give you a sample of Parker lube to lubricate the O-rings before you tighten the adapter fittings back up. You don't want to tear the rings before you have a chance to use the tractor. Be careful when you're putting the O-rings on the fittings to not scratch them or damage them.

 

[cypressfarms]

Thanks for all of the replies (and pm's). I'll be taking the case off this weekend. By the way, it's not cracked. I've had it "rebuilt" before (twice) but maybe they used cheap o-rings? Regardless, I'll be taking it to a local hydraulic/tractor repair place myself to see what they say. I'll get my 14 year old to actuate the loader for me and see where the leak(s) are before I take it off.

 

[cfpinz]

It looks to me like your hoses on the top left are leaking as well, maybe at the fittings but it could be the actual hose. When you check for leaks, use a piece of cardboard. The fluid is under enough pressure it can cut you like a knife.

 

[novatech]

You may consider replacing the quick connect with permanent screw on connectors. If you don't need them they are always a source of leaks over time. If you do use them then I would replace the entire quick connect with a high quality one. Sometimes the constant vibration will wear the metal enough that they do not hold a tight enough seal to the o ring.