rear 3 pt wont lift?

YukonKing · Jan 2, 2008

Hello,

I have a 07 JM254, so far I have about 40hrs on it. Since I have had it the 3pt has not worked the only time that it lifts is if I raise the loader and hold the lift valve on the 3 pt open then lower the loader. Any ideas what the problem could be?

bluechip · Jan 3, 2008

What loader are you using? how many hoses connect the tractor to the loader , 2 or 3 (3 would indicate apower beyond port). Just guessing, I'd say the steering priority valve is the problem. These tractors are normally plumbed so that 100 percent of the flow is directed to the loader valve. This is why the loader works. when the hyd flow is not being used to move the loader, it passes through the loader valve and the next stop is the power steering priority valve. this valve regulates pressure to the steering. You don't mention a problem with your steering so we must have pressure here. However the return line from the priorty valve dumps directly into the tank, without supplying the 3 point lift valve. So my bet is the priorty valve is dumping too much flow back to the tank, and not enough pressure is coming back on the return line that feeds the lift valve. when you drop the loader bucket,there is extra flow from the cylinders which acts to boost the pressure on the main return line. Hope this helps.

Diamondpilot · Jan 3, 2008

I think Blue Chip hit the mark. I had problems with my valve also. You can take it apart and clean it. I found a paint chip in my tractor, a 2003 254. This was in the first 25 hours and now have 425 with no more problems. Either way if you are in a area that is cold it will take about 10 minutes of warm up time to get the hydros working correctly.

Chris

Paddy · Jan 3, 2008

Yukon,

I had a very close problem on my KAMA 454. I had loaned my tractor to a friend and forgot I had the tow bar attached. The yard box interfered in the lift fuction. He did not notice. After a week of use, the 3PH would not raise. We could trick it by "bumping" the loader joy stick. By this trick, the 3PH would raise all the way.

I tried a few things but it was always the same, not working. I ordered the whole valve assembly from Chip, installed and it works fine! The cost was low compared to my time of messing with it. I have the old one still and I plan to rebuild it some day. I'm sure it's one of the many check valves.

Patrick T

Soundguy · Jan 3, 2008

Are those piloted check valves by any chance?

soundguy

Dadsgreenpsd · Mar 5, 2008

I am sure that this has been fixed by now, but I am going to post my experience anyway...

Mine had a pinched o-ring in the 3ph valve, and it could not build up pressure. after chasing everything else in the system, i finally found this o-ring, replaced it, and have had no trouble since.

greg_g · Mar 5, 2008

Dadsgreenpsd said:
Mine had a pinched o-ring in the 3ph valve,

hopefully you replaced the wiper at the same time. When the rear lift is permitted to travel too high, the O-ring and wiper extend beyond the walls of the cylinder. As the lift arms lower, the O-ring and wiper get damaged when pulled back inside.

Now that it's working again, you should set the stop on the lift control lever to limit the upper travel. Some types of implements can also accidentally push the lift arms up, regardless of where the control lever is set. Not much you can do about that, except stay vigilant

//greg//

Brad_Blazer · Mar 11, 2008

That's confusing.
Pinched o-ring in the VALVE = O-ring and wiper on CYLINDER?

greg_g · Mar 11, 2008

Brad_Blazer said:
That's confusing.
Pinched o-ring in the VALVE = O-ring and wiper on CYLINDER?

Perhaps. Since the pinching the O-ring and wiper on the TPH hydraulic cylinder is such a common issue with the 200 series, I may have misinterpreted DadsGreenSpd's use of the somewhat vague descriptive " 3ph valve ". The result of cylinder O-ring/wiper damage is also a failure to " build up pressure ".

//greg//

YukonKing · Mar 15, 2008

Good Day!!!!!

And a good day it is, well I finally made some head way with my 3pt. All it cost was 11$ at NAPA. It was mentioned in a earlier post about lack of fluid gettting to the back of the tractor. I changed my return filter (oil filter type)!!!!!! WOW!!! What a difference, my hyd are twice as fast at least. Very suprised at how much restriction was there. I'll be cutting the old filter apart to see what was in it.

This fix was by coinsidence, I was doing a 50hour service (changed oil/filter, fuel filter and hyd filter), still have to do my head retorque.

Oh yah, while doing my oil change I had a bit of a run-away? While refilling through the top side it was slow to drain, so the valve cover was very full, so to hopefully pull some oil down I cranked with the fuel shut off pulled until I seen oil pressure, then started it. Well i'm guessing that it sucked a bit of 15-40w through the PCV valve line....and away she went!!!!! so very quickly pulled fuel shut of and put my hand over the intake.

Anyways she purrs like a kitten once again.

Thanks to all.