Gurus, i owned my CAT345BL hydraulics excavator just a few month back and i dont have a enough experince on it. Machine is '98 manufactured and stopped swinging after a noise while swinging right direction. My mechanic opened one of the swing GP Motor though it has 2 swing drive motors. Found out that bronze color 9 caps below 9 small cylinders inside bushing were all broken, we were in doubt what can be the root cause of these broken bronze color caps (i don know the exact technical name for this). Contacted to local cat service they also couldnt find the reason plus they couldt explain me why this excavator is equipped with 2 swing drive motor. I have ordered some required parts but until they arrive i decided to ask you and get some useful information. By the way, we checked the 2nd motor, it is ok, everything is in place and not broken but looks like it never worked. In addition to motors, we also cheched the gears below them, they are also fine. Above is the brief description of the issue and would like to ask your ideas, information, suggestion on what can be the root cause of the broken caps and what is the main purpose/function of the 2nd swing motor on this machine? I'm afraid that if i put new motor, it may broke it as well, thats why i want to find out the root cause. I would appreciate any kind of information, lessons learned etc. Sorry for my bad english... Thanks in advance, Cheers, Annaly
A machine Serial Number would help to give detailed advice. Your machine has 2 identical swing motors, Left side & Right side. That's how the machine is built. The swing motor is a piston-type hydraulic motor. The bronze "caps" are the slippers for the pistons (the "small cylinders") in the motor. Does the motor have a data plate with a Part Number on it ..? Your failure mode is reasonably common for a motor that has high operating hours. I would doubt that you can successfully repair the motor without the resources of a dealer shop. If nothing else it has to be tested & adjusted after being rebuilt. Normally if a motor is trashed the way you describe your motor only the outer case can be recovered, everything else goes in the scrap bin. You will need a major cleaning operation in your hydraulic system. Small particles from the failure will have gone everywhere. At the very least you need to drain the oil from the tank and replace it, plus replace all the hydraulic system filters. you may well have to replace the filters more than once. Caterpillar manufacture special High-Efficiency filters that can be used to assist in cleaning out a contaminated system. They will plug more often but they will remove the contamination from the system faster. If you speak to your Cat dealer they will be able to tell you what H-E filters are the equivalent to the standard filters in your machine.
Tap a gauge into the case drain port on one of the swing motors and make sure the pressure doesn't rise too much when stalling the left and right tracks, if the travel motors or swivel is leaking alot it can be a factor in failure of the swing motors.
Nige, The serial number is 4SS01099.