Caterpillar "guts"

[bobcat_ron]

I must have been really bored today, so I popped the cab up to see what and how Cat's "guts" are made of. Getting that cab up was easy, I only used one had, and it just kinda floats up like a cloud, Bobcat was a PITA, and you had to use both arms.

Behold, the "guts":

Fricken' huge hydraulic tank, Bobcat's is only 1/3 the size!!
http://i160.photobucket.com/albums/t178/rdj07/Pictures426.jpg

Neoprene spacers, 1 on top and 1 below, completely isolated from the chassis, a little more complex to remove the bolts, but better vibration control:

http://i160.photobucket.com/albums/t178/rdj07/Pictures428.jpg

Front view:
http://i160.photobucket.com/albums/t178/rdj07/Pictures416.jpg
http://i160.photobucket.com/albums/t178/rdj07/Pictures412.jpg

Valve bank, it is indeed H/H controls:
http://i160.photobucket.com/albums/t178/rdj07/Pictures419.jpg
http://i160.photobucket.com/albums/t178/rdj07/Pictures417.jpg
http://i160.photobucket.com/albums/t178/rdj07/Pictures415.jpg

Main pumps:
http://i160.photobucket.com/albums/t178/rdj07/Pictures414.jpg
The big line coming off is the return, it uses a gravity flow for incoming oil, hence the odd shape of the tank:
http://i160.photobucket.com/albums/t178/rdj07/Pictures418.jpg\
The drive hoses are on the right side, I followed them all the way to each opening in the sides of the chassis:
http://i160.photobucket.com/albums/t178/rdj07/Pictures420.jpg

The cab really tilts back far!
http://i160.photobucket.com/albums/t178/rdj07/Pictures429.jpg


All the hoses are clearly visible, no bolt heads sticking out that will cause damage to the hoses, there are some wires and plugs, but very few, and only running off the valve bank. I also took the liberty of using 3/16" nylon tie wraps around the hoses that I thought might be a problem, but there was only 1 hose that needed it, the rest are quite isolated from the other hoses.

Now compare it with the Bobcat "jungle"
CAT:
http://i160.photobucket.com/albums/t178/rdj07/Pictures412.jpg

BOBCAT:
http://i160.photobucket.com/albums/t178/rdj07/Pictures217.jpg

Which one would be easier to inspect, clean and do preventative maintenance?

[ksss]

A plastic hyd. tank? WTF? Plastic is prone to crack in cold conditions, and does not dissipate heat, but it is cheap. Nice touch looks like they stole a page from BC excavators on that one.

[Scag48]

My guess for the choice on plastic was for less weight and corrosion resistance.

[ksss]

My guess for the choice on plastic was for less weight and corrosion resistance.

Hyd tanks typically are not a source of corrosion, but the weight could be a factor. I think more likely they needed to create a container to match the space available. Plastic is easier to do that with than steel. It just does not have favorable heat transfer characteristics and they get brittle and are more prone to leak. They also are known to collapse.

[iron peddler]

Hyd tanks typically are not a source of corrosion, but the weight could be a factor. I think more likely they needed to create a container to match the space available. Plastic is easier to do that with than steel. It just does not have favorable heat transfer characteristics and they get brittle and are more prone to leak. They also are known to collapse.

the swirl in the hyd tank is the key component, it prevents cavitation and cools the oil before it goes back through the system...material is not an issue on a hyd tank....location is more key when comes to cooling and vibration.

[bobcat_ron]

Now what really stumps me is, I spent 2 hours with my head in this 247, and the burning question is; Is this hydraulic system closed loop or open loop?
I know Bobcat's was closed circut, there was only 1 big line coming of the little hydraulic tank and only a 1/4" line going back in, this tank has 2 massive 1 3/4" lines going in and out.

[qps]

Hyd tanks typically are not a source of corrosion, but the weight could be a factor. I think more likely they needed to create a container to match the space available. Plastic is easier to do that with than steel. It just does not have favorable heat transfer characteristics and they get brittle and are more prone to leak. They also are known to collapse.


Now your reaching KS;)

[cat2]

yea its a little better than the bobcat, but there are some hoses on there that will be a PITA. but you will have that with any machine. I need to get a pic of the Deere. we need a pic of a case and gehl. and compare all of them

[bobcat_ron]

I took an open ended wrench and tried to get on all of the fittings, there ain't much room, but as long as you can crack them loose, they'll move, I've seen plenty of odd sizes of wrenches needed to get hoses off Bobcats, not to mention removing other parts to get to the hoses.

[CarterKraft]

The implement is Open loop, all oil flows from the center pump to the control valve and then out of the big rubber line straight into the tank.

The drive circuit has a charge pump, the first pump, which pumps thorugh the fan motor (AC compressor on the B-series if equipped ) and then to the filter cooler and then finally the drive pump were it is regulated to charge pressure and the excess goes back to tank.

As was said the tank is designed to aid in heat transfer and air extraction.

the tank material is not a problem.

The underhood shots of a C-series is eve cleaner.

[cat2]

Hey i like the name on your dump hopper. " Ron's Bobcat"

[bobcat_ron]

Carter Kraft, you just made me smile: so the Auxiliary hydraulics ARE indeed returned right back to the tank, so in theory, after the oil has come out of the jackhammer, it goes straight into the tank, is this correct? If so, I am jumping for joy.

As for the name on the hopper, that was so the Bobcat dealer could hold it for me while they waited for my check to clear when I bought it.

[Gravel Rat]

Nice pictures of your girl friend :laugh:

The only thing about Cat is they use those fittings with O rings and the two half clamps that bolt on. I had so many frustrating times with those d*mn things.

[bobcat_ron]

It's not very often I get to peek under my girl friends dress!!

Those fittings are tough, Cat has used them for ages, and you never have to worry about over tightening those fittings, the O-ring does a good job.

[mrsops]

ron you have a 247b how wide is that machine? i thought a 256 speced out the same as a t190

[AWJ Services]

The Cat has some nice looking guts.:)

The plastic tank is cheesy and will become an issue at some point.

Can you imagine having a small engine fire and the tank melting and dumping several gallons of oil on the fire?

[CarterKraft]

The cheesy plastic tank has been in use since the first A-models and have not been a problem.

To further everyones fear of fire, how about the 20 some odd gallon plastic fuel tank burning during the theoretical fire.

It seems everyone is lacking the proper safety equipment on there skids.

After having a fuel fire on my drag car recently that burned for less than a minute and destroyed a great deal of expensive parts, everyone needs a fire extinguisher on there machine.

[CarterKraft]

Yes the oil returns directly to the tank, it has to go over the water fall to reach the suction strainer, and then pump, all the while a portion of the tank oil is being circulated through the cooler.

[bobcat_ron]

ron you have a 247b how wide is that machine? i thought a 256 speced out the same as a t190

66" width over tracks, and it is the exact same length as my T190 with a bucket on, or some people measure from the Q/A plate, 99" w/o bucket, Bobcat T190/180 is 130" with bucket/101" w/o bucket.

[YellowDogSVC]

Yes the oil returns directly to the tank, it has to go over the water fall to reach the suction strainer, and then pump, all the while a portion of the tank oil is being circulated through the cooler.

You know, if you could design a good bracket for an extra extinguisher or two, you would have some instant customers!
I have only found one good place to mount an extinguisher on a Bobcat but have been thinking that the open pipe on the loaders arms of the vertical lift machines would make a good place to store a couple of extinguishers. Just haven't figured out how to make them sturdy.

I keep a large one in my cab. Haven't had to use it yet but I feel better. I also keep a few on the truck.

[CarterKraft]

I may take your advise and see what I can come up with.

I think minimum of a 5 lb for the machine and little compact unit in the cab.