tjc1989
Silver Member
Hey guys,
I hate to sound like a dummy, but can someone explain in terms I understand what several of the valves are designed to do and why, on my Branson 4220i rear hydraulic lift? I know somebody out there is knowledgeable enough to help on this.
Specifically the control valve, safety valve, relief valve and stop valve.
And also the draft control.
I am enclosing Branson schematics of each valve.
Mine has a front end loader, which is working OK as it should, BUT, the rear hydraulic lift bleeds off and jerks up and down. Or as some have referred to as hiccups. Its worse when cold, with more rapid jerking, and gets better somewhat when fluid is warm. But even when warm, does not go away. It shakes the whole tractor, if I have a heavy load on the lift , such as an 800 pound tiller.
I took it in to the dealer I bought it from when it was in warranty, and the mechanic advised me he didn't find much wrong with it, but did replace a piston o-ring on the hydraulic piston, and fine sandpapered a small spot on the cylinder. When I got it home, and lifted something , it still did it. I didn't take it back, though I should have. But after having my tractor for 10 days, I was very reluctant to take it back in. PLus the inconvenience, and my lack of confidence in them. Now its out of warranty, and I am going to try and fix it myself.
But I have some lingering doubts on it.
Number one: While rear lift is hiccuping and trying to sustain lift height, if I slightly use my FEL, and slowly lift it up, the jerking nearly subsides all the way, with no loss of rear lift height. When I stop the FEL lifting, it goes back to the jerking. It seems that somehow, the use of the FEL lessens the effect of the jerking, and does not cause the rear lift to drop in height.
A little history:
Tractor has 338 hours.
I have changed fluids and filters twice. I am using Shell universal tractor fluid, and Branson filter. Fluids or filters made no change.
I have tried changing settings on the valve that controls the rate of rear lift drop, by tightening the knob tighter or looser. No effect.
I have tried changing the draft setting by moving the draft control lever to high number and low number. No effect.
So, I am preparing to pull this unit off my tractor and get into it. My fear is that if I can't find anything wrong with the piston or cylinder, then what. I have a very good mechanical background, but don't know what the fluid valves are designed to do.
Thats why I am asking for theory behind the various valves used on the hydraulic lift. I'm pretty sure the Branson dealer mechanic did not touch any of the hydraulic valves when he had it apart.
So is it possible a pressure relief valve could be malfunctioning, or another valve? Could a misadjusted draft control cause this?
I would really appreciate some help on this. Thanks, in advance.
I hate to sound like a dummy, but can someone explain in terms I understand what several of the valves are designed to do and why, on my Branson 4220i rear hydraulic lift? I know somebody out there is knowledgeable enough to help on this.
Specifically the control valve, safety valve, relief valve and stop valve.
And also the draft control.
I am enclosing Branson schematics of each valve.
Mine has a front end loader, which is working OK as it should, BUT, the rear hydraulic lift bleeds off and jerks up and down. Or as some have referred to as hiccups. Its worse when cold, with more rapid jerking, and gets better somewhat when fluid is warm. But even when warm, does not go away. It shakes the whole tractor, if I have a heavy load on the lift , such as an 800 pound tiller.
I took it in to the dealer I bought it from when it was in warranty, and the mechanic advised me he didn't find much wrong with it, but did replace a piston o-ring on the hydraulic piston, and fine sandpapered a small spot on the cylinder. When I got it home, and lifted something , it still did it. I didn't take it back, though I should have. But after having my tractor for 10 days, I was very reluctant to take it back in. PLus the inconvenience, and my lack of confidence in them. Now its out of warranty, and I am going to try and fix it myself.
But I have some lingering doubts on it.
Number one: While rear lift is hiccuping and trying to sustain lift height, if I slightly use my FEL, and slowly lift it up, the jerking nearly subsides all the way, with no loss of rear lift height. When I stop the FEL lifting, it goes back to the jerking. It seems that somehow, the use of the FEL lessens the effect of the jerking, and does not cause the rear lift to drop in height.
A little history:
Tractor has 338 hours.
I have changed fluids and filters twice. I am using Shell universal tractor fluid, and Branson filter. Fluids or filters made no change.
I have tried changing settings on the valve that controls the rate of rear lift drop, by tightening the knob tighter or looser. No effect.
I have tried changing the draft setting by moving the draft control lever to high number and low number. No effect.
So, I am preparing to pull this unit off my tractor and get into it. My fear is that if I can't find anything wrong with the piston or cylinder, then what. I have a very good mechanical background, but don't know what the fluid valves are designed to do.
Thats why I am asking for theory behind the various valves used on the hydraulic lift. I'm pretty sure the Branson dealer mechanic did not touch any of the hydraulic valves when he had it apart.
So is it possible a pressure relief valve could be malfunctioning, or another valve? Could a misadjusted draft control cause this?
I would really appreciate some help on this. Thanks, in advance.
Attachments
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Branson 4220i Rear Hydraulic Cylinder Control Valve Schematic Page 85.jpg176.5 KB · Views: 1,029
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Branson 4220i Rear Hydraulic Cylinder Relief Valve Schematic Page 87.jpg206.4 KB · Views: 1,078
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Branson 4220i Rear Hydraulic Cylinder Stop Valve Schematic Page 88.jpg185.4 KB · Views: 832
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Branson 4220i Rear Hydraulic Cylinder Safety Valve Schematic Page 89.jpg194.1 KB · Views: 986