Anyone with the new 425...

[joshlee]

From the one picture I can see that they started using a different sealant on the gasket in between the two separate pumps. They used to use some kind of shellac sealant, in which mine leaked. So, they gave me another seal that I put on, and it still leaked a drop at the bottom every now and then. Nothing worth worrying about.

 

[marrt]

Thank you Incline.

Yes, this is a Bondioli and Pavesi pump. It's probably a 19 cc HP P2. Recently, the 425 used a 21 cc M4PV and the 1430 used a 28 cc M4PV I believe. Some older 425's used a 19 cc NT10 with an aluminum pump casing. That pump is no longer in production.

So...what's the difference between an HP P2 and M4PV besides displacement? No idea. It's possible the "P" series is a later design because there's a wide displacement range in this series.

 

[Incline]

marrt - so you were making some comments about new model 425's having case drains on the wheel motors. Apparently mine has a return line that I wasn't even aware of.

Does this line flow enough oil from the wheel motors back to the tank to completely flush out the wheel motor system regularly?

You may recall sometime back that there was some discussion about the fact that the wheel motors were on a "closed" system and wouldn't receive fresh oil even if the main tank were changed out. Wondering if this changes that?

 

[marrt]

Hi Andy,

This short answer is...maybe. If the case drain is installed primarily to deal with normal leakage, as opposed to cooling for example, then the leakage should be minimal on a newer machine. In fact, one of the ways to test a pump or motor's condition is to measure this leakage and compare against a stated standard for the pump or motor.

However, there are a lot of unknowns in our case. What is the volume of the leakage? What are the particle sizes that can move past the motor's internal tolerances and end up in the return line? What is the total capacity of the closed loop circuit? What is the volume of the variable displacement pump leakage? Etc...

As a general rule, I would say these case drains do help to swap out the oil in the closed motor pump loop over time. However, the greatest benefit, as mentioned earlier, has to do with long-term reliability of the motor seals.

I hate to keep asking for more pictures, but could you take a picture of the back of one of the front wheel motors where the hoses connect? I'm curious to see if this connection point is an option offered by the wheel motor manufacturer, or is a modification made by Power-Trac (which I suspect).

Tom

 

[Incline]

Here you go.

I'm not convinced this wheel motor is the White CE 14.3 that folks on here generally refer to as the "larger wheel motors" (compared to 15-20 year old 425's). The back doesn't say Roller Stator, the bolts are not recessed, and obviously it now is end ported either by the manufacturer or by powertrac.

Curious what your thoughts are.

 

[marrt]

Thank you for the pictures. Yes, this is a somewhat unique motor for a PT. It's using a square mount but with holes capped for the hydraulic ports. Also, it appears there's a number ending in "CE" on the motor mount? I assume it's still a tapered shaft. The end porting is an option for some Danfoss (White) motors. Because the end cap has cast lettering, this is not a PT fabricated end cap. It also looks like it may have medium duty bearings. I'm convinced this motor has been spec'd by PT. My only question...is this a custom OEM assembly (i.e., not readily available for retail purchase) or can we find the exact specification. So far, I've not found a way to spec this exact motor on Danfoss's website.

I notice the parking brake plate is now bolted on. Not sure why but it can be removed if not needed...and to stop the "clicking" from the pin rubbing. I redesigned my parking brake (actually, a friend did) and it's much better now. I need to post some pictures.

I'm always trying to figure this stuff out not because I don't like paying PT's high prices on parts. Personally, I've got no problem with their pricing because it comes with free tech support from Terry (plus, if you think their prices are high, try buying some stuff for a Bobcat or Takeuchi). I want to know what's in these machines because I'm curious. Plus, if I want to upgrade something (like I recently upgraded my 14.2 cu. in. wheel motors to 22.8 cu. in.), then PT doesn't offer this option and I need to know what to order. In addition, there's no guarantee PT will be around forever and, since they mostly use off the shelf parts, I want to know what's in my machine.

 

[Incline]

I haven't been able to find any pictures of wheel motors like this either but there's a ton of 'em. No "CE" markings that I could see. There were these stamped numbers but they didn't lead me to any particular motor.

35713
4474544 - Google reveals that this is a patent # assigned to White Hydraulics
6321

One day I'll just call up PT and ask them. Mostly I was curious where it sat in the power spectrum.

 

[m5040]

Here you go.

I'm not convinced this wheel motor is the White CE 14.3 that folks on here generally refer to as the "larger wheel motors" (compared to 15-20 year old 425's). The back doesn't say Roller Stator, the bolts are not recessed, and obviously it now is end ported either by the manufacturer or by powertrac.

Curious what your thoughts are.


View attachment 619334View attachment 619335View attachment 619336

While we are somewhat on the subject and I just want to learn about these, what does the Roller Stator signify?

 

[MossRoad]

I think this might explain it better than my words...

 

[marrt]

As far as I know, this is a brand name. It's probably a play on words from the electric motor world (Rotor/Stator). This motor is likely a gerotor design which is common for small high torque, low speed motors.

For even more torque, the next step might be a fixed displacement piston motor. And for even more torque, add a planetary gear set. For example, a tracked machine will often use a hydraulic motor coupled with a planetary gear set to drive the tracks.