Having drive issues with the JLG 40HA which does not seem to be an uncommon problem. We performed the series of troubleshooting steps with everything pointing towards the pump since nothing happens when we manually override the servo control with the plastic lever. We even capped the main lines out of the pump and tried the same steps and there was absolutely no change in RPM (no laboring of the engine). We brought the pump to a hydraulic shop and they said the pump was really worn-out. Any chance anyone knows where we can find a used Sundstrand MPV046C pump? Or a really good place to purchase remanufactured Sundstrand pumps? It would be really nice if this place was in the New England area. Thanks in advance for any help.
Have you checked with JLG? You can go online and download their parts manuals. Up to serial number 29318 they used a 13 spline pump, part # 3600164 which doesn't come up when I Googled it. Ser.# 29318-69000 used a 15 spline pump part #3600260 which comes up numerous times when Googled. If needed I'm not sure what would be involved in replacing a 13 spline with a 15 spline but I would think just the pump drive plate. Hope this helps.