Hi all, and thanks in advance!! I have a 2010 Cat 304c cr that I bought new and now has approx. 1100 hrs on it... About 200hrs ago the stock thumb started to "weep" down. While the machine is running, the thumb slowly closes on its own and consistently needs to be opened back up. It is quite annoying......I have looked for leaks on the hydraulic lines to the thumb, seals on the cylinder, etc. and have found nothing. The hydraulic fluid in the reservoir doesn't appear to be dropping. Could it be a problem with the seals on the cylinder and I should have them rebuilt? Just seems a little early to me for that to need to be done...... Also, pertaining to the thumb, the switch that opens and closes the thumb on the right hand joystick appears to work backwards. This is how the switch was set up from new. When I recently jumped in another Cat excavator, the switch worked in an opposite manner which seems more intuitive. Is there a way to switch the function of the thumb controls? Just thought I'd ask you all first. You guys seem to be a lot more helpful than the dealer......Cheers
You could have some crud in your thumb relief valve or it's slipped adjustment. Seems to me that you could just reverse the wires on the solenoid valves to correct the switch issue.
Thanks Lil'Puss! I guess I'm not sure what the thumb relief valve is and how to adjust it. Also, does anyone know where the solenoid valves are located to switch the thumb switch around?
Consult the wiring schematics in your manual. You might be able to trace back the "retract" circuit for the thumb to the valve. Look for an acorn and stop nut and adjusting screw.
Thanks again for the response..not sure if your getting the same cold snap I am (I'm at the base of Mt. Baker, barely made it above 20 today). Planning on a full service, cleaning, etc. next week. Will look for the retract circuit as you said. Don't have the shop manual yet. Not sure if the owners manual has the schematic. Also, any recommendations for a 1000+ hour service other than oil, filter, fuel filter, final oil? HAve done these things every 250hrs but not much else.
Nice looking machine there! Yeah, we're in that cold snap too been in the low twenties past few mornings. Pulled all the trailer batteries day before yesterday. Being up by Baker, I'm guessing you're getting ready for some snow soon. Your maintenance program sounds good. Does Cat say to change final drives at 250 hrs? Seems soon to me. I change my engine oil by analysis, engine oil filters at 250 hrs., air filters at 500 hrs. or as required.
The operating manual should spell out what needs to be done at certain hour intervals.