bobcat ron
Banned
I cannot even begin to imagine what you are talking about. I would very much like to see a schematic of the system. Are you saying that one piston pump powers the drive, both left and right sides? And the other of the two powers the hydraulics? Is there then a control valve for the drive? There would have to be if one pump powers the drive. Do you know this?
On a Bobcat K-series, the separate valve and filter you refer to is for control of fan speed which actually reduces power loss by only allowing the fan to spin fast enough to maintain operating temperature, which you continually dismiss as too hot. It's a technological advancement, call it good or useless, but it's all about efficiency. The filter protects the system from the fan motor, never a bad idea.
In earlier posts, you implied that all of the circulating oil goes through the cooler, that's why it runs so cool, etc., and now you're stating that oil moves through the cooler at 5 gpm via the charge pump. Which is it for Pete's sake?
While it's certainly true that I don't know as much about CATs as I do about Bobcats, I believe I know more about Bobcats than you, and I'm beginning to feel that you don't know as much about CAT's as you want others to think you do, and that all your ranting about the CAT's superiority and your constant degradation of anything except CAT is mostly hype and nonsense. I thought you were a digger rather than a rabid CAT salesman.
And, trust me, I still like your website.
I'll do some more reading through the book on the weekend, but the system is a true open loop except for the drive, the way it works is all the oil coming out of the loader/bucket/drive goes through the manifold to the tank, the manifold is on the bottom of the machine and the oil is forced up through the bottom of the tank. Although the drive system is closed, the excess pressure that builds up has to be released much like a case drain, that's why there are 3 lines to each motor. Meanwhile, the oil is also being recirculated through the cooler/fan/filter by the charge pump and it also sucks the oil from the suction line on the right side of the tank. There is only 1 drive pump, it's a big multi-piston deal with the control valve on top and 1 pump (pistons) that powers the loader/bucket and a third gear pump (gear) for the auxiliary and the smaller charge pump.
The mechanic I talked to back in December told me how it works because the first thing I had them do is install a 2rd line from the loader to the tank (for hammer return) but he said it was redundant as the system is already open loop, but I still wanted it so it would act as a case drain for the brush cutter I run.
But on a side note, I can have the grease monkey's at Cat put a high flow system in, just add another pump and valve with extra lines and Bob's my in- bred Uncle.
But if I can get the digi-cam to get super close ups of the exploded views, I'll make a separate post.