Hopefully you haev this one figured out and fixed by now. If not-
1- Hose/pressure wash the heck out of your radiator and oil cooler, even though they look clear. I have had one that I would have sworn was clear looking at it that ended up having so much crud in it that I had to pull the radiator and cooler and soak them overnight to get it loosened up so I could get them clean. Be careful if you use a pressure washer, the fins on the radiator are kind of wimpy and easy to bend.
2- Make sure the problem is with your machine and not the hammer. Take a line and put a coupler on each end and connect it at the quick connects so it just loops. Run the hydraulics for several minutes (10 or so) and see if it overheats.
If it overheats with the loop in place, check you pressure relief valve and the spool valve for the Aux hydraulics. Pull the cover (right between your legs when you are sitting in it) and the valve is right there. If you end up needing parts, right now it might be cheaper to get a whole new spool valve from
www.surpluscenter.com. Search for "Husco". I think the valve they have right now for $139.00 should fit your machine (part number may be different, but same valve). There is pretty much nothing on that valve that you can get from new holland for $139.
If it does not overheat with the loop in place, the problem is probably in your hammer. Without knowing what kind of hammer it is I cant give much advice on it, but one thing to try right off is running the hammer with the machine at 3/4 throttle. A lot of those hammers for some god unknown reason are only designed to run at 2100 PSI and they have terrible pressure regulators built in that produce a lot of heat.
