Hi guys, I am trying to get both pumps on a Cat 312 to load up when using a hydraulic hammer. The digger at the moment doesn't have any aux piping and the service manual has the plumbing layout for some fancy system with ball valves. What i would like to do is to make both pumps work during hammer use so that one pump doesn't prematurely wear out. I can pipe for single pump one way delivery no problem, but just need some help on how to get both pumps flow to the aux piping for one way flow. Any help would be appreciated. Pictures or a diagram of an actual machine would be nice although i have the diagrams on the service manual just can't figure out how to pipe the pilot hoses. Thanks
If you have enough flow from one pump to run the hammer properly you would be fine doing it that way. The design of these pumps is pretty good and you don't need to worry about wearing it out from over use. The biggest wear out factor on these pumps is contamination, aeration or cavitation.
Hi Mobiltech, The flow is just about enough from a single pump, but from our experience with the Cat 312 the single pump gets used so much more than the other that during a pump overhaul one pump is all but destroyed and the other is normally worn. This is due to tha fact that these machines use the hammer 100% of their lifetimes and the pump usually needs new pistons and block etc after about 1500-2000hrs of running like this. Even one of the driveshafts get pretty badly worn and the other side is like new! I have probably seen about 10 of these already and always if you run breaker without setting up the machine for double pump flow, then one pump almost always takes the brunt of the load and gets worn out twice as fast. So if anyones knows the procedure for getting both pumps to run i would be most grateful! Thanks
Hi there, I have a cat 312c and you can use the computer in the cab to choose between single and dual pumps for hammer and shear settings. It may ask for a password to access the settings and I believe the factory default is 0001 which worked for me. It's simple enough to switch once you get used to the menu system
Hey Cardie, Yeah you get that option on the 312B and 312C but not on a straight 312. So thats what i am trying to solve. I need to get the "plumbing" for the 312 correct because on this model it all works via the ball valves on how the flows from the 2 pumps are combined. So thats the problem i'm trying to solve. If you ever come across any 312 with the fancy ball valve system please do take some pictures on how the pilot and main lines done as that would be awesome!
Call Cat and get the diagram. This will make like a lot simpler.
IIEC I already helped the OP out with a Hydraulic Schematic for this particular 312.