Lifting capacity

[BobRip]

Does anyone think that there is a safety factor when one adds, say 200 lbs to the rear of the PT in order to increase the lifting capacity. Do you think the relief valves will activate when you raise a load greater that your rated lift? Do you think the relief valves should be reset?

When I bought my PT in 2000, I asked "Is that the lifting capacity at the quick attach plate or at the attachment?". I was told it is at the attachment in normal use (not quite at guote). It is my belief that the relief valves are set for the rated load. Most tractors need weight somewhere to achieve their potential, so adding a couple of hundred pounds on the back is not excessive.

 

[Bob999]

Most tractors need weight somewhere to achieve their potential, so adding a couple of hundred pounds on the back is not excessive.

I agree with your statement about most tractors. However, to the best of my knowledge the PT is not designed to be used with additional weight. I don't believe that PT recommends or condones the use of loaded tires, or any other form of additional weight.

I think the design philosophy and standards used by PT are quite different from most tractor manufacturers. For example many tractor manufactures sell weights and attachments to add the extra weight. PT does not.

 

[MossRoad]

How many of you have conventional tractors with FELs that will lift the rear tires off the ground before the reliefs kick in?

My old International weighed quit a bit. I was never able to lift the rears off the ground, even with the oversized cylinders. The rear would get a bit light, but never leave the ground. The PTs hydraulic lift system seems overpowered for the weight of the machine, to me. I would think that the designers of a machine would want no possibility of the rear end coming off the ground and would set the reliefs low enough to prevent that. Of course, I'm glad they didn't on our PTs! But that would make sense to me for liability issues.

 

[J_J]

David, I haven't heard any of the 425 people mention anything about the relief valves, maybe for this reason. The rear end leaves the ground before the relief pressure is activated.

 

[MossRoad]

David, I haven't heard any of the 425 people mention anything about the relief valves, maybe for this reason. The rear end leaves the ground before the relief pressure is activated.

Yep. I was very surprised and still am at how easily I can lift the rear end off the ground. When the rear end comes up, I know it is time to take a smaller bite, as I don't want to stress that center link. I think if I follow this gut instinct, the unit will last a good long time. If it doesn't, well, I can weld.

 

[BobRip]

I agree with your statement about most tractors. However, to the best of my knowledge the PT is not designed to be used with additional weight. I don't believe that PT recommends or condones the use of loaded tires, or any other form of additional weight.

I think the design philosophy and standards used by PT are quite different from most tractor manufacturers. For example many tractor manufactures sell weights and attachments to add the extra weight. PT does not.

Bob999, you may be right, but there is no way my PT422 can lift 800 pounds without the extra weight on the back. And, I still remember (like I really trust my memory) the PT statement that the rating is at the attachment (where on the attachment I am not quite sure). I don't think it would be good to lift 800 routinely, but a few times a year should not hurt. I guess it is my belief that the relief valves are what protects the machine.

 

[RegL]

David, I haven't heard any of the 425 people mention anything about the relief valves, maybe for this reason. The rear end leaves the ground before the relief pressure is activated.

I was wondering about that also. I have the 1430 and if the tractor is straight, the relief valves usually kick in before the rear raises. Actually, I was wondering how to test the relief valve to see if it's set correctly. Is it even adjustable. Does anyone know where the valve for the lift circuit is located.

 

[J_J]

I was wondering about that also. I have the 1430 and if the tractor is straight, the relief valves usually kick in before the rear raises. Actually, I was wondering how to test the relief valve to see if it's set correctly. Is it even adjustable. Does anyone know where the valve for the lift circuit is located.

On my 1445, there is a small block at the left rear that has two relief valves.
As far as testing, or adjusting, you can plug a gage in the circuit and adjust. You can do this by teeing in a gage, and try to lift an imoveable object, that way, you can see and hear when the relief valves are operatig. Before I put a hydraulic gage in my system, I was having trouble with the lift capacity , which was very low. PT told me to send them back to them, and they would check the relief pressure. I could have taken them to a local hydraulic shop for testing, Anyway, they tested OK. It turned out to be the lift pump, which I believe was leaking internally. A new lift pump fixed my problem.

 

[Bob999]

I still remember (like I really trust my memory) the PT statement that the rating is at the attachment (where on the attachment I am not quite sure).

Perhaps you were told that the rating is at the attachment point. That is the only way a tractor could have a single rating as I understand it. This is because each attachment has a different weight and the effective point of the load differs (it is much further out with the mini-hoe than with a bucket). If the lifting capacity were listed at other than the attachment point PT (and any other manufacturer for that matter) would have to publish a table of lifting capacity--with the small bucket = xxx, with the large bucket = yyy, with the mini-hoe =zzz, etc.

 

[Barryh]

I would think it is rated at the attachment point minus the attachment weight. Other load factors being hot hydraulic fluid, verses cool. Load lifted on level ground verses, up hill down hill, straight articulation verses turned.

I've never really heard relief valves kick in on my little tractor while trying to lift up or pull loose a tree stump, but I'm sure they have. In most cases the back end would not come up it seemed to just bog down. I have had the back end come up, while lifting things like over size trees or rocks.

Looking at the size of these tree’s being wet and rotted. I am positive, my PT has lifted its rated 600 pounds if not a little more on many occasions.