whimpy lift curl on 1850

[wasabi]

this is a recent model low hour 1850...

while most hours this summer has been mowing, i've recently been digging a little and moving loads. the lift and curl functions can't be normal....they frequently stall altogether and/or i need to go down and/or out to reactivate any significant lift or curl power. when it does work normally it is whimpy at best. more of a bother than a major problem....

until now...i've been digging a little and pushing some and the hydr problem seemed to become more pronounced to the point pressure seems to leak off and the tractor wants to climb the bucket.

anyone venture a guess as to how to isolate and diagnose this whimpy lift/curl circuit?

 

[LD1]

this is a recent model low hour 1850...

while most hours this summer has been mowing, i've recently been digging a little and moving loads. the lift and curl functions can't be normal....they frequently stall altogether and/or i need to go down and/or out to reactivate any significant lift or curl power. when it does work normally it is whimpy at best. more of a bother than a major problem....

until now...i've been digging a little and pushing some and the hydr problem seemed to become more pronounced to the point pressure seems to leak off and the tractor wants to climb the bucket.

anyone venture a guess as to how to isolate and diagnose this whimpy lift/curl circuit?

I am not familiar with the PT but I will try to help you anyway.

First, is it like a tractor in the sense that it has a joystick and quick disconnects??

Does the lift seem to have good power. If it does, try switching around the lift and curl QD's and see if the problem still exists. If so, it could be a design thing IF the lift is still good.

Secong, you really need to put a pressure guage on it. This will help a lot with the diagnosis.

Third, it could be curl cylinders leaking by. Try giving a little more RPM's. This will give a little more force if there is a internal leak-by in the cylinder by giving it more GPM .

I could not find a rated breakout-force or rollback force for that machine. It could be that it is just that way. Or is it something that has gotten worse.

 

[SpringHollow]

a couple of general comments:

- there are certain geometries where the curl is very weak

- i had problems with lifting when i had leaks in my steering cylinders.

I would get some Tees and a pressure gauge in order to get a feel for what is going on.

Ken

 

[woodlandfarms]

On my 1850 my curl fails at full tilt down, meaning it won't right the bucket until I drop it a bit. Bad Geometry.

But.... Looking at the circuit.

The oil comes from the Charging Circuit (It is on the drivers side of the engine compartment, down past the back wheel, a big square of aluminum with a weird cylinder screwed into it).

Oil goes from it to your steering system, then to the lift tilt dump, then back to the tank.

If your tractor steers fine your issue is not with pressure nor with the circuit. It is slightly possible your tilt dump is plugged. This would either be in your cylinder (when you turn the tractor off does the cylinder tip down immediately?) or in the control. Controls can be cleaned but not for feint of heart or wrench.

But more than likely it is one of the 2 following.

You are over-loading the circuit. Remember their are two cylinders (although geometrically challenged) doing the lifting, so tilt and dump is not as strong.

You are doing the move in combination with another move. Meaning you are turning or lifting while trying to dump.

On the 1850 we have a guage for that circuit on our brake system I believe. I have not fully traced the brake system, but I believe that guage indicates for that particular pump that operates steering.

I would say check through the range of motion while parked., not turning the wheel. but with the brake off.

Carl

 

[SpringHollow]

Carl is correct - the steering has priority over the lift so if you are sending fluid to the steering cylinders, your ability to change lift/curl is definitely reduced. You also need to be running at near full rpms to get full capacity.

As far as digging into hard ground, remember that you only have 1200 lbs of lift capacity. That is not much. So if you are driving into the ground with your bucket and trying to lift while still driving into it, your pt will definitely want to climb over your bucket.

My curl/lift capacity is significantly reduced in certain geometries. I can have trouble lifting full loads of water/clay/shale when the bucket is low. Tipping the bucket bucket some until i get the loader raised a foot or two then gives me greater capacity. But don't quote me on that. What i need to do has become second nature so i do not remember the details.

Do you have a tooth bar on the bucket? That significantly improves my dirt digging capabilities. It concentrates the force instead of trying to use the full lip of the bucket.

But the bottom line is that the 1850 is designed as a slope mower with limited loader capabilities. 1200 lbs is not a lot for a tractor with a 65 HP diesel. But then you can lift those 1200 lbs on slopes that a normal CUT could never consider. Cleaning out the ditch on my property means climbing out at angles of over 20 degrees in two directions with a full load up at least 2-3'. All my CUTs would have rolled at much smaller angles but they would have done it while being able to lift a greater load

Ken

 

[J_J]

I believe your machine is a little different than my 1445, but my steering valve has a priority circuit that uses the fluid first. I would recommend you install a gage before the steering valve and lifting and curl valve. If you have the pressure to the lift cyl and the relief valve goes into relief, then you have whatever pressure that was set, probably around 2750 to 3000 psi. Are you saying that you can not lift the 1200 lbs limit, or just sometimes?

On my steering valve, the fluid flows through the steering first, and if the steering is turned to the limit, I get min lift if any. What the steering valve does not use, goes through the lift and curl circuits. If you can not lift your rated load, that means that the steering valve is probably leaking. Check and see if your steering valve can maintain the pressure. Turn the steering to the center, and try and lift a heavy load, and monitor the hyd gage. If the cyl and valve is good, the lift and curl should perform as when new.

I had to replace my steering/lift/curl pump, when I noticed the lift would only lift about half the rated load. . I had previously rebuilt the cylinders, and had the valve checked.

Check the pressure off the pump, Stall the steering and check pressure. Check the pressure at the cylinders at max load.

Check and or clean the relief valve for the lift circuit.

I believe the hyd gage will guide you in solving your problem.

 

[ponytug]

As other have mentioned, steering has priority. There is also the detail that if any of the cylinders are at lock, you will have tripped the pressure relief and not much will happen.

I will aslo say it took a little time to figure out best tactics for the use of the PT for earthmoving. Some of the tips on board here to use the tractor weight and momentum have been very useful to me.

All the best,

Peter

 

[wasabi]

thanks for all the feedback and advice. I think part of the problem is I've become spoiled by the lifting and digging capabilities of the 2445 and the 1850 pales in comparison....but i'm also convinced I'm not lifting the full 1200 lbs I'm awed by the 1850's mowing prowess and suspect over time it will perform fine with trencher, post hole digger, tiller, etc...,

fwiw, most of the digging was in moderate soil, albeit rooty...with minimal steering activity. Lifting is smetimes noneexistent until I joggle the up down a few times so I half suspect I may have to go down the trail that J J tracked.

It was chilly here over the weekend --- low 30's---so I opted for inside carpentry over outside tractor repair. It is supposed to warm up into the sixties today so I'll tackle repair of the damage from climbing the bucket (cylinder pushed on the quick attach control box and bent/broke three hose connections and one fitting) and then proceed with more detailed diagnosis. When I head back to SC I'll stop by the tractor supply store for guage and tee's...and when I return I'll hook all that up and report back what I find out.

thanks again....never cease to be amazed at the knowledge and willingness to share that TBN "brain trust" offers. I appreciate yall!