Limits on reverse speed

[BobRip]

Bob,

I did read what they said about synthetic. No such thing as to careful when it comes to expensive equipment. That's why I’m always second guessing myself on the best way to take care of mine. I also run synthetic.

I know my Robin is new and I could be wrong, but it seems like I had my little gasket leak problem after I put in the Amisol synthetic.

It probably had nothing to do with it the gasket was a little deformed. Just makes me a little suspicious that it might too darn slick. Thus my thinking of maybe changing back regular dino.

I probably won’t but if I did, then I would want maximum protection in a straight 30-W for excessive heat in the summer.

Just for your information I have been running Mobil 1 for over 500 hours on mu PT Robin engine. No problems. It's your decision of course.

 

[ddonnell]

Hydrostat or PT treadle, if you don't engage a brake of some sort, things will try to move on an incline of more than 10-15 degrees without braking. Knowing your machine, CUT or PT, is the ultimate equalizer in any situation. Certainly a newer machine will make this hydraulic braking quicker, as seals, new cylinders, etc. are tighter and fluid motion will be much more restricted. A new unit stops on a dime and gives 5 cents change. Age the system and add some heat from an hour or two of use and things get a little sloppier. That's why I think a fairly hefty "manual" spring system under the pedals, treadle or otherwise, to take it to neutral is a good idea. It wouldn't have to be much of a spring to return any pedal system to neutral quickly without causing undue extra foot power to depress the pedal in whatever direction you wanted to go. I don't know about you guys, but when I'm jamming into a pile of dirt with the bucket, trying to get that last 30 lbs. in the load, I find myself trying to push the pedal through the floorboards. LOL. I doubt I'd have too much problem with a spring system trying to take me to neutral braking. JMO.

 

[KentT]

What I call neutral is any position that inhibits forward or reverse travel. Having said that, I will almost bet that if your PT is on a down hill slant and you release the treadle, thinking is in neutral, with engine on or off, that it will probably move. Mine will. If you think that neutral is safe, it isn't. Just like the bucket arms that leak down, those wheel motors will turn. Try this when you can, raise both front wheels off the ground, and try and turn one of the front tires in the forward direction. I am thinking that the other wheel will turn in reverse.

JJ, IMO there's no direct relationship between one front wheel and the other since they're on separate circuits. Turning one front wheel (or trying to) should pump fluid toward the rear wheel on the same side -- which in your example wouldn't be able to move.

Are you suggesting that the return from one wheel circuit becomes the supply to the other wheel circuit, driving it in reverse? How does that fluid get by the rear wheel motor where the wheel is still sitting on the ground -- in either circuit? It would have to flow backwards (including the fixed rear wheel first on the other side) to drive the other wheel in reverse, wouldn't it?

I'm trying to understand your view of the circuits and how they work...

 

[BAGTIC]

Moss,

You said your PT goes 8mph forward and backward. I know 8 mph is what the PT website says but it seems to me that on smooth level gound it is actually much faster. I wish I could time my PT425 on a paved road. It seems like it tops out at closer to 18 mph than 8 mph.

 

[J_J]

JJ, IMO there's no direct relationship between one front wheel and the other since they're on separate circuits. Turning one front wheel (or trying to) should pump fluid toward the rear wheel on the same side -- which in your example wouldn't be able to move.

Are you suggesting that the return from one wheel circuit becomes the supply to the other wheel circuit, driving it in reverse? How does that fluid get by the rear wheel motor where the wheel is still sitting on the ground -- in either circuit? It would have to flow backwards (including the fixed rear wheel first on the other side) to drive the other wheel in reverse, wouldn't it?

I'm trying to understand your view of the circuits and how they work...

What I have told you are actual facts and observations. How this happens, I haven't figured out yet. I wished I had a hydraulic plumbing diagram. My circuits may not be like yours, so what I say is only relative to my machine. I have had the 1445 off the ground, and the rear wheels will do the same thing. I could make a video I suppose.

 

[MossRoad]

Moss,

You said your PT goes 8mph forward and backward. I know 8 mph is what the PT website says but it seems to me that on smooth level gound it is actually much faster. I wish I could time my PT425 on a paved road. It seems like it tops out at closer to 18 mph than 8 mph.

I think it seems faster than it is because you are close to the ground AND there is no suspension. But it is quick enough, that's for sure.

 

[MossRoad]

What I call neutral is any position that inhibits forward or reverse travel. Having said that, I will almost bet that if your PT is on a down hill slant and you release the treadle, thinking is in neutral, with engine on or off, that it will probably move. Mine will. If you think that neutral is safe, it isn't. Just like the bucket arms that leak down, those wheel motors will turn. Try this when you can, raise both front wheels off the ground, and try and turn one of the front tires in the forward direction. I am thinking that the other wheel will turn in reverse.

That's why I keep my feet on the pedals when operating and set the brake and shut it off every time I get off the unit (except when warming up the hydraulics in the winter, when I do get off the unit while it is running).

 

[johara1]

MR,my 422 goes both directions at the same speed also.i don't see any thing wrong with it,very usefull when moving large amounts of material.......jim

 

[Barryh]

Just for your information I have been running Mobil 1 for over 500 hours on mu PT Robin engine. No problems. It's your decision of course.

I'll probably staying with the synthetic thanks.

 

[MuncyBob]

Barry, I also changed to Mobil 1 on the first oil change. Now at 250 hours and no leaks other than a filter I did not get tight enough 1 time. I also practice a little overkill and change out the Mobil 1 every 50 hours...I think I could probably go longer with the Mobil 1 oil but it's not that expensive....YET!