Improvements You Need on PT

[Clumber]

I installed some restriction valves that have worked great and are easy to adjust. I only installed two for the FEL arms, but it's easy enough to do for the other circuits too.

http://www.tractorbynet.com/forums/power-trac/49694-hydraulic-flow-restrictors.html

Phil

[on edit] in looking at that old thread, maybe I put the restrictors on the curl circuit. It's been SOOOO long and my memory isn't as good as it used to be, and it used to be pretty crappy. I put them in so I'd have better control of the stump grinder. I don't think I've messed with the restrictors since, things just work as I expect them to.

Thanks, would you have any photos or videos?

Patrick

 

[MossRoad]

I am assuming that reducing RPMs means easing back on the throttle? Also, is lift capacity and height affected by restricting flow or reducing RPMs?

If the torque of the load exceeds the torque of the engine, the engine will stall.

You can prove this by putting your FEL bucket under the bumper of your truck and trying to lift it at idle, medium throttle and high throttle.

At idle and probably at medium throttle, you will stall the engine, while at high throttle, you will pick the back of the PT off of the ground (or pick your truck up, whichever comes first).

 

[MossRoad]

Also, on a gas engine like in our PT400 series tractors, the engines are meant to run at a constant 3600 RPM for cooling purposes. While there is little to no chance of overheating the engine by running it at low RPM for precise control in tight situations, you should be aware that running the engine under 3600 RPM for long durations with a heavy load on it could overheat the engine.

 

[J_J]

Just curious what the 425 can lift with extra weight on the back. Have any of you checked your relief pressure?

 

[BobRip]

Just curious what the 425 can lift with extra weight on the back. Have any of you checked your relief pressure?

On the 422 I lifted an 819 lb rock with the fork. I had a weight of 110 lbs and my neighbor (about 170) on the back. I doubt if it could lift more. I could not steer very sharp or the tail would lift.

 

[Clumber]

Also, on a gas engine like in our PT400 series tractors, the engines are meant to run at a constant 3600 RPM for cooling purposes. While there is little to no chance of overheating the engine by running it at low RPM for precise control in tight situations, you should be aware that running the engine under 3600 RPM for long durations with a heavy load on it could overheat the engine.

Interesting discussion. Lots of questions come to mind. Without a Tac, how does one estimate the engine RPMs. How much throttle should be used for different tasks and attachments. For example, should your run full throttle when mowing or brush hogging -- will that overheat the engine. Is half throttle about 3600 RPMs???

 

[Phils]

Thanks, would you have any photos or videos?

Patrick

If you read far enough in that thread you'll find a pic of the two valves installed.

Phil

 

[BobRip]

Interesting discussion. Lots of questions come to mind. Without a Tac, how does one estimate the engine RPMs. How much throttle should be used for different tasks and attachments. For example, should your run full throttle when mowing or brush hogging -- will that overheat the engine. Is half throttle about 3600 RPMs???

Wide open is 3600 rpm. Mowing is one of the toughest loads, always mow at full throttle For intermittent loads you can cut back, but never lug an engine. Going down hill I wil throttle back and then raise speed going up hill. Sounds too complex, wide open all the time.

Lots of good ideas here. Thanks.

 

[J_J]

Hyd pump GPM's is determined by engine rpm. High engine rpm equals faster cylinder speed, and a faster hyd motor as on attachments. .

 

[KentT]

Unless I'm using a mower deck or the stump grinder (i.e. a powered attachment), I usually operate at about 3/4 throttle all the time --then speed up/slow down if tramming a long distance. It slows down the hydraulic actions enough to where you can control them. It's almost impossible, IMO, to use the mini-hoe with any accuracy when running full throttle. The lift/curl circuits are just TOO jerky -- I'm slamming and banging all the time, unless I slow the engine down. I may have to think more about putting restrictors in that curl circuit. But, as Bob cautions, I also make sure not to lug the engine.

I'm surprised there haven't been more suggested improvements...