3-Point Hitch help with my 3 point lift

[Turbo]

johnstractor

This has some useful info

 

[alana1]

Ok, it's kicking by butt. Replaced hydrolic fluid with AW-32, flushed with diesel, cleaned out sump and inspected piston and o-ring, safety relief valve, up/down handle and internals, front/back and inside of cylinder, adjusting valve and internals. All o-rings and gaskets were in great shape. Suction screen is near perfect. After i was done, I primed the system and everything worked, loader and 3-point up and down. Ran it for 5-10 mins then hooked up the box blade and the 3-point only worked for about 1 minute, then it only goes down. Almost like its the safety relief valve leaking by excessively, but not sure. Any ideas?

 

[Rich Waugh]

The only thing I can think of is something changing as the fluid and/or pump and other parts warm up with use. You might take thermometer and check the temp after 1 minute of run time and again when it fails. Try that a couple of times, letting things cool for several hours between tries. If it seems to fail at the same temp each time you've learned something - not sure just what, but something.

So, what could change with temperature? viscosity sure, but that shouldn't change that much, unless your temperature is really soaring. If it is, then you have a problem you need to find ASAP. If not, then what else could be happening? Maybe a seal failing under temperature, or clearances changing in the pump? A pressure gauge could detect that happening, I would think.

Some things to think about, anyway.

Rich

 

[YukonKing]

I've got an idea, how about a air leak on the suction side. It would take a while for it to become full of bubbles. Otherwise as for as finding it i'm not sure. Tighten clean and reseal joints. Do you notice bubbles in the fluid?


Just a thought.

 

[alana1]

I will try the temperature of the oil when i get ahold of a thermometer to do that. the resevoir does get some bubbles after i use it for a bit, the bubbles are all less than 1/8 inch or so and only on top of oil. A pad about 1/4 inch thick or so, i will check the suction of the pump, there's only two connections between suction screen and pump. Even though i dont need the 3 point right now it's driving me nuts.
Thanks Guys

 

[Diamondpilot]

You said the loader was working fine and you had no power steering from what I remember. If that is the case the issue is probably not with air. My guess is even though the seals looked fine when they get hot they are allowing leak by. I think you need to rebuild the rear lift with a new seal kit.

Chris

 

[alana1]

Yeah, a seal kit is in my mind now also. I just learned that the divider block for the FEL has a pressure relief valve also, and thats where the 3-point gets its fluid supply from. From the pump, into the divider block, from the divider block to the FEL Cylinders and to the 3-point. I need to check/find FEL relief valve with a 3000-4000 psi guage i guess. At the moment i dont know what brand the FEL is and it has no nig obvious stickers on it.
HMMM!
Thanks again

 

[dcyrilc]

Yeah, a seal kit is in my mind now also. I just learned that the divider block for the FEL has a pressure relief valve also, and thats where the 3-point gets its fluid supply from. From the pump, into the divider block, from the divider block to the FEL Cylinders and to the 3-point. I need to check/find FEL relief valve with a 3000-4000 psi guage i guess. At the moment i dont know what brand the FEL is and it has no nig obvious stickers on it.
HMMM!
Thanks again

I can sympathize with what you're going through. I'm down in Snohomish county and I'm fighting just the opposite problem with my 3PH. No down after 1-2 minutes. Lifts like there is no tomorrow though!

 

[Rich Waugh]

Cyril,

Have you adjusted the valve under the front of the seat that controls the outflow from the 3PH? Often that's all the problem is. If you go to adjust it, be sure to clean it thoroughly first so you can find and back out the set screw that locks it in place before yo try to turn it. Otherwise you'll bust the knob off. Screwed in all the way keeps the TPH from dropping and on some tractors diverts flow to a rear remote. All the way out and it drops like a rock. I adjust mine to get a decent drop rate for whatever weight implement I have on it at the time.

Rich

 

[greg_g]

I'm fighting just the opposite problem with my 3PH. No down after 1-2 minutes. Lifts like there is no tomorrow though!

Hydraulic return flow is restricted excessively. As Rich pointed out, it's controlled by the valve in front of the seat.It's there to compensate for implements of different weights. Obviously heavy ones will fall faster than light ones.

Don't force the knob though. Down pressure (weight) must be removed from the lift arms before adjusting the flow control. Adjust the valve with the implement on the ground. If it won't drop at all, jack the implement up enough to take the weight off the lift arms. Hold it in place with jack stands or something while you open the valve a little. If the knob still won't turn, the internals are likely rusty (old fluid/inferior fluid/wrong fluid attracts moisture). Remove the entire assembly from the hole, give it a bath in WD40. Reinstall.

//greg//