Liquid Power

[MossRoad]

...I have learned to drive in reverse at full speed very well! LOL!

That is my favorite way to drive the PT with a full bucket, regardless of if it is manure or something not so sweet smelling. The reason is simple... if you have a full bucket two inches off the ground, going 8MPH across the yard and hit a bump, the bucket hits the ground and the PT has to push it over the bump. Very rough ride. In reverse, however, the PT just has to pull it over the bump. It acts as its own skid plate and just slides along. I find I can go much faster in reverse than going forward with a full bucket. This is the only reason to get arm rests on the PT. Just lean out the side like a train engineer and take off in either direction. If only they had a steam whistle!!! Wooo WooOOOOOOoooo!!

I'd like to see conventional CUTS do that! Would be a scary ride, for sure!!!

 

[RegL]

That is my favorite way to drive the PT with a full bucket, regardless of if it is manure or something not so sweet smelling. The reason is simple... if you have a full bucket two inches off the ground, going 8MPH across the yard and hit a bump, the bucket hits the ground and the PT has to push it over the bump. Very rough ride. In reverse, however, the PT just has to pull it over the bump. It acts as its own skid plate and just slides along. I find I can go much faster in reverse than going forward with a full bucket. This is the only reason to get arm rests on the PT. Just lean out the side like a train engineer and take off in either direction. If only they had a steam whistle!!! Wooo WooOOOOOOoooo!!

I'd like to see conventional CUTS do that! Would be a scary ride, for sure!!!

reverse is also handy when carrying a big jag of brush with the grapple bucket. Their are often some long stragglers that get under the wheels if going forward but will just drag behind going in reverse.

 

[MossRoad]

That sounds like an excellent way to handle brush.

 

[J_J]

The observations that you made of the hose layout is probably correct. The wheel motors and pump, are in a closed loop system, and I believe that the case drains of the wheel motors and pump go to the cooler and then tank. If any one line is pushing fluid through the cooler, then the tank oil is being cooled. The amount of oil that can be forced through the cooler could be limited by the size and strength of the cooler, which I am sure that it is low pressure.

Don't be too concerned by what people think. Your effort and diligence in this area is much appreciated. Just state the facts as you know them.

Did anyone come to a definitive answer about where the hydraulic fluid comes from that is cooled by the hydraulic cooler? On my 1445, there is a manifold on the back right side of the tub, that has several hoses that I believe come from the case drains of the wheel motors, the tram pump, and then to the cooler. Since the tram pump and wheel motors are in a closed circuit, the fluid that is cooled, comes from the case drains, due to internal motor leakage , and pump leakage. This fluid is replenished by the charge pump, which has a pressure around 325 psi. Most variable speed pumps have a charge pump. This helps to keep the closed system full of fluid. That is good logic for never running the pump out of fluid, and bleeding the system of air after replacing the filter. This hyd oil for the charge pump, comes directly from the hyd filter. That is the best answer that I can come up with so far. I am still looking .

 

[NJBill]

JJ
if you read the first two paragraphs on #14 of this thread you will see that from the right lower corner of the Sauers Danfoss valve bank, ( that's on the left) A 1/4 inch hose goes directly to the cooler, that is the only feed to the cooler, and the oil leaves the cooler in another 1/4 inch hose directly to the tank return. The oil passes through 3/4 inch tubing. I mentioned the number and size of the fins because when I was in automotive the size of the condenser determined the size of the unit, like 1 1/2 ton.
Please remember this is probably the only 422 with this hose routing.
And the wheel motors are the only system fed directly fom the filter.
Thanks JJ

 

[BobRip]

Did anyone come to a definitive answer about where the hydraulic fluid comes from that is cooled by the hydraulic cooler? On my 1445, there is a manifold on the back right side of the tub, that has several hoses that I believe come from the case drains of the wheel motors, the tram pump, and then to the cooler. Since the tram pump and wheel motors are in a closed circuit, the fluid that is cooled, comes from the case drains, due to internal motor leakage , and pump leakage. This fluid is replenished by the charge pump, which has a pressure around 325 psi. Most variable speed pumps have a charge pump. This helps to keep the closed system full of fluid. That is good logic for never running the pump out of fluid, and bleeding the system of air after replacing the filter. This hyd oil for the charge pump, comes directly from the hyd filter. That is the best answer that I can come up with so far. I am still looking .

I don't believe my 422 has case drains. When you have case drains does that mean that there are three hoses on each wheel motor? Mine only have two. I think this may be the difference that we are seeing.

 

[J_J]

I don't believe my 422 has case drains. When you have case drains does that mean that there are three hoses on each wheel motor? Mine only have two. I think this may be the difference that we are seeing.

Bob, All four of my wheel motors have a case drain. My tram pump also has a case drain. I also have probable the only radiator cooled engine, and the 45 hp engine is gas. Must be one of a kind. I think that each model cools the hyd oil, but with different methods.

On the subject of what oil is being filtered, all the hydraulic oil is being filtered, but at what rate. I have no idea why they only filter the oil going to the tram pump. The oil in the hydraulic motors and pump is filtered the most. That oil is cooled and then dumped back to tank, and then the other systems use the oil from the tank. That means that if you are working in a stationery position, the wheel motors are using little oil. Some oil is being filtered, because the filtered oil goes to the charge pump, which only adds oil to the circuit as needed. Any excess goes into the case and out the case drain. Someone with a different machine can explain their system. I would rather PT filter every circuit, other wise three filters. Each circuit can filter out it's own trash or crud. It probably has to do with economics. They didn't want to make it too sophisticated, because they think that we, the owners might not understand the system.

 

[BobRip]

Bob, All four of my wheel motors have a case drain. My tram pump also has a case drain. I also have probable the only radiator cooled engine, and the 45 hp engine is gas. Must be one of a kind. I think that each model cools the hyd oil, but with different methods.

On the subject of what oil is being filtered, all the hydraulic oil is being filtered, but at what rate. I have no idea why they only filter the oil going to the tram pump. The oil in the hydraulic motors and pump is filtered the most. That oil is cooled and then dumped back to tank, and then the other systems use the oil from the tank. That means that if you are working in a stationery position, the wheel motors are using little oil. Some oil is being filtered, because the filtered oil goes to the charge pump, which only adds oil to the circuit as needed. Any excess goes into the case and out the case drain. Someone with a different machine can explain their system. I would rather PT filter every circuit, other wise three filters. Each circuit can filter out it's own trash or crud. It probably has to do with economics. They didn't want to make it too sophisticated, because they think that we, the owners might not understand the system.

JJ, good summary. I was told that the tram pump is the most suspectible to dirt, so that was why it was filtered. It would be nice to have all systems filtered, but it would take more room, cost more, and be more maintenace.

My big beef is no filter on the filler cap. The new ones have this, but not mine. I would think a fair amount of dirt would get in through that. I know somebody added one, but I don't think I have the tools for this. Maybe I do and don't know it.