We have rebuilt hydraulic pumps on our EC 330 and PC 220 both at about 6500 hours. I thought these pump should last longer than that. What are we doing wrong?
Changing filters at too long of an interval ???
What interval do you recommend? Sent from my DROID RAZR using Tapatalk 2
As I recall Komatsu recommended changing filters at 1,000 hours and hydraulic oil at 2,000 hours. One can't say what is normal though as they all vary by types of operation, types of attachments and the diligence of the operators in replenishing the tanks after things like blown hoses and repairs. Most contamination is dumped in the tanks in the operations I've worked around. I have yet to have much luck with anyone but a couple of dealers that can rebuild the things.
Also pay to check your oil specs, I found that the oil that had been run in machines where I am was not up to manufactuers spec. I think our PC300 did a pump very early in its life but has now done approx 8000hrs. The PC200 here has now done about 9000hrs and still going good. It has been run with underspec oil, had poor service intervals,a humid envrionment. I had engines that had not had an oil change for 1000hrs but i think the hyd oil was turned over due to the amount of blown hoses. It has blown probably every high pressure hose at least once. Most of these would have been changed in the field. A lot of hoses have been cut and made onsite and cleaning out the new hose or even being careful not to get dirt in the new one before fitting was not done until I came. just throw an open ended hose in the ute then on the ground then pick it up, give the end a bit of a wipe with a dirty rag and fit it. Oil was put in whatever drum could be found to get to site, or even around the workshop and wiping filler caps or ensuring that no dirt got in when the cap was taken off was never a priority. So either you are doing something terribly wrong, just having a bad run, or this place is just blessed
Sounds like a place i used to work!
Are you having your hydraulic oil sampled and analyzed at regular instervals. If yes, what ISO Cleanliness Code it it showing ..?
We have not done that. Sent from my DROID RAZR using Tapatalk 2
In that case unfortunately all bets are off. If you have no idea how clean your hydraulic system is then you can't take the necessary action if the oil is "dirty" and consequently the life of critical system components is likely to be much less than the optimum. Sorry.
If the oil was dirty that would most likely be the problem?
Dirty is a relative word when speaking about hydraulic systems. You can have an oil that looks as clean as new oil but still has particles in it that are too small to be seen by the naked eye. Typically they will be between 6 microns & 40 microns in size. By comparison a human hair is typically 80 microns in diameter and the human eye has difficulty seeing anything smaller than 50 microns. Improving the condition of the oil by removing these "invisible" particles can increase hydraulic component life by a factor of 2-3 times, or even more. Do you often have problems with oil leaks that require frequent top-ups of hydraulic oil..? Anything from hoses to leaking o-rings, to cylinder seal failure.
Lots of bad o-rings and even a cylinder failure.
What also hasn't been mentioned is overheating hydraulics. When I see lots of leaking O ring flanges, bleeding boom lift cylinders and bubbles in the outer covers of hydraulic hoses I know to also look for plugged radiators and seeping engine coolant hoses. It is pretty easy to spot.
Good point. Basic attention to external cleanliness and keeping cooling systems in top condition is always a good start. I think you've answered your own question in the OP .............
I am not sure what that is supposed to mean. Sent from my DROID RAZR using Tapatalk 2
My apologies if I was not clear. So you have previous history of "lots of bad o-rings and even a cylinder failure". This brings 2 things to mind. 1. Hydraulic system overheating was most likely the cause. Were the o-rings hard when they were removed.? I bet the seals on the failed cylinder were probably cooked (dark orange instead of the cream colour of new ones) too. 2. Where oil can get out, dirt can get in, especially in the case of cylinder seals as the rod moves back and forth. That's more than likely where the contamination has been getting into your system. Of course all the oil top ups you have to do every time you have a failure don't help either. Sticking to normal filter change intervals will not help in this case. So your o-rings & cylinder were just early warning signs of a system in trouble. The pump failure was just another logical consequence. It's just that metal parts wear slower than rubber/plastic ones.