Hydraulics questions

[Marks481]

It would help to compare the PT1850 and the PT1460 side by side. The points to consider:
1. Is the lifting arms on the PT1850 as beefy (as thick of steel) as the PT1460 so they can support the same weight (PT might have saved weight here by using lighter gauge steel).
2. Do both models use the same lifting cylinder. It seems that the cylinders installed on the PT1850 should be more then adequate to lift 2400 lbs.

If the two models have similar lift arms and the same cylinders, then there has to be a restrictor valve somewhere that is throttling flow to reduce/divert pressure from the lifting cylinders to derate it. If so, it seems like an easy fix...

 

[J_J]

Carl, Did you read my earlier post above? I thought I stated the how and why very well.

What is the heavest weight that you have lifted. Did the back end ever come off the ground?

The weight that you can lift is dictated by the psi, cylinder size, and how it is connected. to the lift arms. I am sure that PT designed it that for safety reasons.

Do you understand why a skid steer can lift more that a PT? Best reason is that the end part of the fulcrum is connected to a point over the rear tires, and large cylinders, and maybe higher psi. A skid steer simply has more muscle, but a PT is more versatile.

 

[J_J]

It would help to compare the PT1850 and the PT1460 side by side. The points to consider:
1. Is the lifting arms on the PT1850 as beefy (as thick of steel) as the PT1460 so they can support the same weight (PT might have saved weight here by using lighter gauge steel).
2. Do both models use the same lifting cylinder. It seems that the cylinders installed on the PT1850 should be more then adequate to lift 2400 lbs.

If the two models have similar lift arms and the same cylinders, then there has to be a restrictor valve somewhere that is throttling flow to reduce/divert pressure from the lifting cylinders to drat it. If so, it seems like an easy fix...

Tim, The explanation might be as simple as , what weight can the PT lift and keep the rear wheels on the ground, and use that as the advertised lifting weight.

Pt will never tell you to add weight to balance things out.

 

[Bob999]

I had understood the design decision to be that it was related to the ability to lift weight on slopes. Now I am told I am wrong...

So, what is the rational to take a 65HP tractor, who's lighter and less HP brethren (the 1445) lifts 750lbs more. If the tractor will go over extended then why not design the tractor to lift at its limits?

My understanding of the design philosophy of the 1800 series tractors is that the design was optimized for mowing steep slopes safely. I suspect that if you compared the 1445 to the 1845 and the 1460 to the 1850 side by side you would conclude that the center of gravity of the 1400 series machines is higher than the 1800 series machines--because the lifting components are larger/higher/heavier.

Another consideration of the lower lift capacity of the slope mowers may be related to the side forces generated on the tractor lifting mechanism when carrying a maximum load (low) across a steep slope. It appears to me that the PT lifting mechanism is relatively weaker to side forces than it is to vertical forces.

 

[woodlandfarms]

I went with the 1445 as other than engine specs, they seemed to be in the same weight and length class. Also, in the pictures the arms seemed to look in the same weight class (thickness of construction), the 1460 is clearly a 2000lb heavier beast and it shows everywhere.

No, I just stall the PT when lifting something too heavy. I have no experience with PT pucker on the machine so far. I wonder if any of the other 1850 owners have had pucker? How about 1845 owners?

Yes, JJ, I got the fulcrum notes and kinda understood some of the hydraulics numbers. Really appreciate the research. And in looking at the photo's of the two, it looks like the 1445 places the hinge points much higher on the tractor than the 1850 (first flaw in my grand plan?)

So, anyone know if the pistons in question are different from the 1445 to the 1850?

 

[Charlie_Iliff]

I wonder if any of the other 1850 owners have had pucker? How about 1845 owners?

re: 1845 - Yep, sure have. I have enough time in various operation situations with the 1845 to say that the established limits are just about right. The relief valve opens just when the rear gets really light. A number of times, I have picked up enough weight that a slight turn brings one rear wheel off the ground, and a few times have had both rears up. I've never checked the actual weight, and don't know if 1200 is right. On the "If some's good, more's better" philosophy, I certainly would like more lifting power. I need it for less than 1% of things I'd like to do, however, so modification (or a new 1460) aren't worth it to me.
As you can see, the 1430, 1845 and 1850 have essentially the same lift assembly and capacity. Clearly, you are right that the 1850, particularly, could have been designed with higher capacity than it has. The reason why it wasn't, I suspect, is that if loader function was to be your primary use, PT offered a real increase in function with the 1445 and 1460.
The answer: get a 180, a 425, an 1850 and a 1460. Oh, and maybe a couple of 24xx.

 

[woodlandfarms]

Charlie

I just brought your idea about expanding my fleet to my wife. It, I thought, was the best idea anyone has ever suggested to the forum.

I now have a black eye and a guarentee of some lonely nights alone. Thank you very much...

 

[J_J]

I went with the 1445 as other than engine specs, they seemed to be in the same weight and length class. Also, in the pictures the arms seemed to look in the same weight class (thickness of construction), the 1460 is clearly a lb heavier beast and it shows everywhere.

No, I just stall the PT when lifting something too heavy. I have no experience with PT pucker on the machine so far. I wonder if any of the other 1850 owners have had pucker? How about 1845 owners?

Yes, JJ, I got the fulcrum notes and kinda understood some of the hydraulics numbers. Really appreciate the research. And in looking at the photo's of the two, it looks like the 1445 places the hinge points much higher on the tractor than the 1850 (first flaw in my grand plan?)

So, anyone know if the pistons in question are different from the 1445 to the 1850?

Carl, I don't remember if you purchased your machine new or used. One thought I had was that your lift pump might be a little weak. A hydraulic pressure gage is a must to trouble shoot hydraulic system. I bought my 1445 used, and realized that it was not lifting its rated load. After replacing the pump, I raised the rear off the ground for the first time. . I know that I can lift more, just by adding weight to the back. If you know the max psi on the cylinders, you might be able to tweak out a little more psi on the relief valve, or the relief valve might not be set right. I believe that your machine has about 3200 psi. We have three hydraulic shops in the area, and I talk to them quite often. If you have any shops in your area, take the machine to them and ask them to check pressure and flow. They will charge you by the hour. Note down all the readings. It's best to do this when new, so then you can use those figures as a reference.

 

[Charlie_Iliff]

Charlie

I just brought your idea about expanding my fleet to my wife. It, I thought, was the best idea anyone has ever suggested to the forum.

I now have a black eye and a guarentee of some lonely nights alone. Thank you very much...

Any time - your buddies on TBN are always happy to provide free advice.

JJ's right. Thorough testing of pressures and flows is the first step, before any mods.
If you want some great bedtime reading, take a look at Mark Chalkley's threads on his EarthForce. You'll end up wanting one, but I suspect his isn't for sale. It will give a lot of info about engineering changes, if that's what turns you on.
By the way, if you want real lifting power, get a heavy duty forklift mechanism from a junkyard and mount it on a trailer axle, rated at 10,000 lb., or so, and weld on a quick attach so the axle is just ahead of the PT tires and trailer tires are close outside. If you find the right parts, you can make a 7500 lb. forklift. I'll leave to you how to mount a bucket on your new unique machine.

 

[cqaigy2]

Any time - your buddies on TBN are always happy to provide free advice.

I think that "free" may be debated by some of us.