PT Rises from the Ashes

Sedgewood · Sep 11, 2003

My new filtered vent cap. I machined off the old cap and drilled and tapped mounting holes for the new one. The new one has no dip stick but there is a screen which hangs down just the length of the old dip stick such that if I see oil covering the bottom of the screen the tank is up to level.

While I had the cover off I spent a fair bit of time wiping down every surface I could reach. In addition to the larger bits like welding slag the whole interior was covered with a thin film of very fine particles. Dust from all my road work last year maybe? There's a scary thought.

Sedgewood

MossRoad · Sep 11, 2003

May I suggest getting going by acquiring some new toys rather than my calamatous approach which, effective as it may be, has proven to be a rather too traumatic way to acquire site material!? 

Sounds like words to live by!

ACQUIRE NEW TOYS!!!

Maybe I'll get a tattoo of that on my .... /forums/images/graemlins/tongue.gif

Charlie_Iliff · Sep 11, 2003

PT's limited to absent assistance in the rebuild 

Dennis:
Although John had to go it alone on his rebuild, the Power Trac attitude was attributable to the insurer's threat to claim against PT. Although I think Power Trac over-reacted to that threat, and lost a sale, I have not heard of any other reports of lack of cooperation or support when repairs have been needed. Generally, Terry's advice is good, and parts are sent promptly. Just don't threaten to sue 'em and you'll be fine. /forums/images/graemlins/grin.gif

duane · Sep 11, 2003

John,

I agree. The 3 main issues with a hydraulic system, heat, pressure and cleanliness.

Pressure: covered by the safety valves
heat: very interested in what you get for maximum hydraulic reservoir temps
Cleanliness: Other than original construction or filter replacements, the on-going sources for possible contamination are the quick connects and the vent. I think the variable volume pump and wheel motor circuits should be okay. Nice job with the vent modification. I keep looking for a filtered vent cap that will go right on the existing mount. I'm still looking.

Duane

Sedgewood · Sep 11, 2003

Charlie: Dennis:
Although John had to go it alone on his rebuild, the Power Trac attitude was attributable to the insurer's threat to claim against PT. Although I think Power Trac over-reacted to that threat, and lost a sale, I have not heard of any other reports of lack of cooperation or support when repairs have been needed. Generally, Terry's advice is good, and parts are sent promptly. Just don't threaten to sue 'em and you'll be fine. 

I agree. It was my insurer's threat that caused the over-reaction. Factory support has generally been good where no threat of liability is concerned. Mention the "L" word and they get antsy.

Sedgewood

Sedgewood · Sep 11, 2003

duane: the on-going sources for possible contamination are the quick connects and the vent. 

There's another - cylinder rod seals are considered to be a major source. from what I read, a separate reservoir is recommended for hydrostatic drive.

Sedgewood

bmac · Sep 11, 2003

10W-30 gets too near the viscosity spec limit on the hot end to suit me 

sedgewood,
please forgive my sick sense of humor, but here goes:

I guess anyone who's used to running their tractor ablaze would be sensitive about performance on the "hot end".

Sorry, I couldn't resist. Nice job on the restoration.

BTW, is there a thread that addresses exchanges between you and PT and the lawyer? I must have missed it.

Bruce

marrt · Sep 11, 2003

PT changed the vent cap on all new production tractors. I forgot to ask if the new vent cap would fit the older tractors. I also did not ask why the change was made. At the time, my thoughts were elsewhere. Anyway, FYI.

marrt · Sep 11, 2003

I don't think Pt's filtration is sufficient. Consider the following quote:

"Hydraulic oil straight from the drum, has a typical cleanliness level of ISO 4406 21/18. A 25 GPM pump operating continuously in hydraulic oil at this cleanliness level will circulate 3,500 pounds of dirt to the system's components each year!"

WOW. That's scary. Also, suction-side filtration is generally not recommented due to the potential to create cavitation. However, I don't see a reasonable alternative. I don't think its practical to have filtration only on the return-side. This would mean fluid in the tank would need to be very clean at all times. In the PT design (any design in my view), this isn't practical.

Edward_DiMaria · Sep 11, 2003

Guys - I know we have been going around and around on this filtration issue - it seems to creep its way into every thread -
So I thought that we should really get this nailed down so all can be confortable or unconfortable given the way it works, comparables, alternatives etc.

I seem to remember on one thread that no filtration was taking place without tramming - but then someone clarified that and informed us that the charge pump circulates the fluid (fliter and through the cooler)

But many folks still seem to have big concerns about this (besides the welding slag / etc - which is a manufacturing defect not a filtration defect)

Some folks proposed separate filtration for the tram circuit - which seems to be a good idea but can it be done? - Also why is the suction filter design a bad choice? I asked PT - "is 100% of the oil filtered and the answer was yes - I guess I am just confused by all this

So I ask the question - what are the variuous methods of filtration - how does the big manufacturers of Skid steers do it? like Bobcat, Cat etc

(It would seem to me that this would be a good comparison because they use the same type pumps bolted directly to the engine except they have two tram pumps (one for each side)
Not sure how many other pumps they use but it has to be similar

One other thing is that it would seem that we would be constantly talking about pump / wheel motor failure if there was a serious problem with filtration and to my knowledge I only recall hearing about one such failure (a wheel motor on an older machine - was it Davesick?

What does everyone think - maybe we need to make this a thread - I know we have a thread in hydraulic fluid alternatives but not filtration