I have an 03 cat 257 serial numbers cmm00558 got the machine used and changed all fluids and filters, the main pump started whining almost instantly so it whines only when tracking but not when using the bucket. i haven’t put any real hours on it since and yesterday I pulled the suction screen out to see if it was dirty and it wasn’t but I did notice the fluid was twinkling… (a good bit of metal shavings) I’m new to owning one of these and I’m kind of stuck, does that mean my pump is bad or could it be something simpler? Has no loss of power and operates as it should as far as I can tell but I’ve been hesitant to run it hard until I find the issue… thanks in advance advance for any advice here…
All the components in both the drive (pump & motors) and implement systems (pumps and hydraulic cylinders) use oil from that tank. The problem that is generating the particles (are they gold or silver in colour?) could be anything but most likely to be a pump or a drive motor. Even when you find the culprit and make repairs you will then need to clean out the complete drive/implement system unless you want another failure in quick time. If the whining noise was not there before the oil was changed what oil did you put into it.?
The previous owner was using a T04 10w trans/hydraulic oil so I stuck with that to not risk mixing the wrong stuff. From what I can tell it’s pretty much the same as the hydo 10 but I really don’t know and could be wrong. Also the shavings are silver.. I’m wondering if they had some sort of additive in it to quiet it down in order to sell it..
10W TO-4 will work just as well as 10W hydraulic, so nothing wrong with the oil you are using. That appears likely if all you did was change the oil and the noises appeared at the same time. Maybe they even put heavier oil in it as a temporary fix. Try moving a magnet through the oil. Does it pick up the particles.?
Will try the magnet and get back to you on that one..
Could be, they put a Zinc additive to the oil, especially if it was owned by an old timer.
Try asking the previous owner saying something like “I’m about to change the oil and want to keep the same type. Also BTW were you using any anti-friction or anti-rattle additives in it.?” Play dumb and see what sort of answer you get. Worth asking at least.
Unfortunately it was a trade in so I got it from a dealer who had limited info.. I did put some gauges on it today and I’m only showing 400psi on the charge pressure.. should be at 450 low idle and closer to 480 high. Not sure where to go from here though…
Start pulling things apart I would say.
I was thinking of pulling the charge pressure relief valve first to inspect and clean, then maybe the charge pump itself.. I’m really hoping the hydrostatic pump doesn’t need replacement but I have a bad feeling…