Cat track loader purchase

[DMiller]

Now THAT'S a Hoss!! Makes that 973 look like a timker toy!! By the black slime on the truck frames coal yard tractor.

As to the diverter valves, should be a block assembly and will have as much flow in either direction but only in either direction. I have seen them placed on other machines, not on a Cat as yours and lived as long as I knew the machines.

 

[DMiller]

May wish to see if Nige will chime in as to Power Beyond ports on the existing valve block, may be able to set it up easier than expected if does have, and if adding a CAT third valve is a choice could be that easy.

 

[ippielb]

Yeah, my local cat dealership got the tender to rebuild all the d11’s that work in the coal mines in BC for teck coal. They take the blades off and ship them 900km here to be rebuilt. Each machine gets rebuilt twice and then sold I believe? I have a few buddies that work for them in Elkford BC. Funny part is that the d11’s are the smallest machines up there. Other then the 16m’s. They just got a big Komatsu wa1200 loader when I went on a mine tour.

 

[Fri973]

There’s no way I’d spend that kind of cash to put one on. If it was closer to 5 grand I’d do it. But I should be able to go get my machine from cat Monday.

Weird thing about the 973c units. You cannot curl your bucket back and lift up at the same time. It was designed to close off the lift valve when you start curling, who’s the idiot engineer who put that in...

Something is wrong with your machine if it won’t curl and lift at the same time

 

[ippielb]

Something is wrong with your machine if it won’t curl and lift at the same time

I thought the same thing, but cat designed only one function at a time.

 

[DMiller]

I suspect this has to do with Cylinder sizing for the capacity of the 973 and the available flow/pressure off the hydraulic pump. Most likely a method to preclude premature starvation failures and/or complaints of Sluggish/slow hydraulic operations. Get too much pump that can handle the flow/pressure demand and the heat builds pretty quickly in no load bypass.

 

[Fri973]

I thought the same thing, but cat designed only one function at a time.
View attachment 186846

I own a few 973’s
I have been running one for 36 years I’m operating one right now as we speak they all lift and tilt back at the same time that’s how you load the bucket By lifting the bucket while Your tilting so you don’t spin a track

 

[Birken Vogt]

With narratives like that, if they did a lot of reading they need to cite the publication and page number so people can go read it for themselves. Just like if you are claiming a building code says something, cite your source. It is not that hard to do.

 

[Cmark]

Here we go:

"When the tilt control lever is moved to the TILT BACK position, pilot oil is sent to chamber (15) and tilt valve spool (16) moves upward. Oil from the main pump is sent from inlet passage (12) to tilt spool (16). Movement of tilt spool (16) has now blocked the flow of oil to passage (14). Oil flow is directed to load check valve (11) .

The load check valve prevents reverse oil flow which can cause cylinder drift or load loss. Load check valve (11) does not open until the oil pressure becomes greater than the force of spring (10) and the head end pressure of the tilt cylinders. The oil opens the load check valve, flows through passage (8) and out passage (7) to the head end of the tilt cylinders. This causes the bucket to tilt back.

Oil from the rod end of the tilt cylinder flows through passage (6), around tilt valve spool (16) and through passage (1). The oil continues to flow around lift valve spool (13) and through outlet passage (9) to the hydraulic tank. As the oil from the rod end of the tilt cylinder bypasses the tilt valve spool and the lift valve spool, the TILT BACK and RAISE operations are prevented from occurring at the same time. When tilt valve spool (16) is in the TILT BACK position, no pressure oil flows to lift valve spool (13). The lift circuit is inoperable."

 

[petepilot]

interesting never set foot in a 973 but i have ran just about every thing else in the cat line at one time or another.the 73 must be the only one built that won`t work as it should

 

[Birken Vogt]

I don't know anything about Cat track loaders. But I have operated a few backhoes and noticed something similar with boom and crowd. When you pull one full the other ceases to function, can't remember which. My hands remember when I am doing it.

My solution is to run the RPM a little faster and operate each valve at a partial position so that they are both getting some of the oil. I think my dad once said it is done this way for a reason, to keep them moving in kind of a floating scenario.

Could this be what is happening with you guys that lift and curl at the same time, that you are operating the valves partially?

I always wondered why they don't feed the oil that is coming out of the first cylinder on down the line to the inlet of the next valve, so that they both work under series flow.

 

[Fri973]

If you put your lift lever in the lockout position hoist up and go into a pile you can still tilt the bucket up and down to load it and the hoist will continue to raise My guess is you have a weak hyd pump which is easy to test

 

[ippielb]

I own a few 973’s
I have been running one for 36 years I’m operating one right now as we speak they all lift and tilt back at the same time that’s how you load the bucket By lifting the bucket while Your tilting so you don’t spin a track

Yeah just like I thought, hence why I told them to try and fix it. And they looked into it, find a C model 973, and let me know what you experience.

interesting never set foot in a 973 but i have ran just about every thing else in the cat line at one time or another.the 73 must be the only one built that won`t work as it should

That’s what they think too, unsure why it does, I’d much rather have the ability to jack the cab up, and do both functions as once but that’s life.

If you put your lift lever in the lockout position hoist up and go into a pile you can still tilt the bucket up and down to load it and the hoist will continue to raise My guess is you have a weak hyd pump which is easy to test

That is not correct if the valve is designed to close off the lift circuit when curling that’s what it’s going to do, absolute worst idea if I’ve ever seen one.

 

[Welder Dave]

Maybe it gives maximum roll back pressure not to have any oil diverted to the lift cylinders. I have a much smaller 931B and the roll back has a lot more power than the lift. A 973 being able to dig into much denser piles might need all the roll back power it can get.

 

[Nige]

It seems to me reading the O&M Manual that there is a detent system where the Lift control can be pulled into the "Raise" position and it will stay there until either it's manually pushed back to the Hold position or until the lift arms reach the level at which the kickout operates. Is that correct..?

If so then I would suggest that filling the bucket is a similar process to that on the big wheel loaders where the modus operandi is to pull the Lift lever into the "Raise" detent as soon as the bucket is well into the pile and then feather the Tilt lever between the neutral and tilt back positions as the machine slowly moves forward. Every time the Tilt control returns to neutral the hoist will raise slightly. Keeping sufficient down pressure on the front end using the hoist function avoids tyre spinning on a wheel loader, I assume it would avoid track spinning on a track loader in just the same way. I think this is what Fri973 was suggesting above.

 

[Fri973]

Set your bucket flat on the ground and put the throttle at maximum and pull your hoist lever all the way back and hold it until it goes all the way to the top and stops if your pump is good that should take between six and seven seconds if your pump is weak it will obviously take longer over 10 seconds is really bad you need to replace the cartridge

 

[ippielb]

I’m going to go pick up my machine today, got two people interested in getting work done. I’ll let you know what my machine does with that Fri973

 

[Nige]

As an additional comment you should have the oil in the hydraulic system at normal operating temperature (<65 DegC) before doing that test. If the oil temperature is too low the cylinder cycle time will be on the high side.

Tilt cylinder cycle time from full dump to full tilt back should be around 2.5 seconds.

 

[ippielb]

Thanks for the additional numbers. Got the machine home. Didn’t feel like taking the chains off the bucket and warming up the hydraulics on the trailer. Might be able to do a couple jobs this week so i’ll Wait until I’m in the field.

 

[ih100]

Never been on a 73, but a lot of time on 43's, 53's and 63's, all with joysticks (very few two/three - lever machines here). Never had any trouble lifting and crowding at the same time, but I can't see any need to lock the lift into the detent position.

Out of interest, Why would anyone spec separate levers for each function over joysticks? I started out when there were still a lot of Traxcavators and Drotts about, and never got why Cat took about twenty years longer than International to fit a joystick.