Hola, I'm new to the message board so please dont flame me too hard. I am having a serious problem with my Mayco LST80. A little background, the pump was working perfectly, we stopped to shorten our line length (remove 1 section of pipe), tried to resume and nothing (no bad internal noise of something broken). We have gone through everything on this pump including rebuilding the primary hydraulic pump and the damn thing still will not cycle. The pump never gets a pressure load or tries to cycle although there is great oil flow. All manual valves have been inspected, cleaned and re-installed. All pressure valves have been inspected, cleaned and re-installed. The spools are in great shape. No concrete blockage in either piston or in the shuttle. We are waiting on new pressure valves as this is the only thing that I can see that would keep the pump from cycling at this point. I am lost as well as every hydraulic mechanic that has looked at it. Any help would be great. Thanks.

The pump pressure regulator is stuck on 0, clean it out and I think you should be good to go.

Thanks for the reply. Are you familiar with this model pump? If so, could you please tell me where this regulator is located because as far as I know, everything has been removed, cleaned, inspected and re-installed. I just want to make sure I havent missed something. Thanks again.

Its mounted on the main hydraulic pump. make sure you check that the spools are free & no springs are broken. I hope this helps.