Thanks for those who helped me locate information on my Monarch hydraulic pump. We located manufacturer's infro, and it is a M-683. Designed for snow plow use, and that was what I was using it on.
Developed a leak on a port on the side that looked like a threaded rod with two jam nuts on it.
Took the risk of taking it apart without a service manual, which I would have dearly have loved to have had. Turns out the port is indeed a pressure relief valve. The bottom nut is the valve body which holds the spring that holds the ball valve shut. The threaded rod is a 3/8" x 1" coarse thread setscrew. (Think of a common setscrew like you would find on a v-belt pulley, only longer.) The top jamnut is actually a nut with a plastic insert/washer which forms a seal at the top of the valve body. That setscrew, which had a hex shaped hole recessed in the top had snapped off right at the junction of the valve body and the jamnut - this allowed fluid to escape past the threads, go through the crack, and leak into the recessed hex hole in the setscrew. Craziest thing I have seen in a long time!
On a Sunday, only parts place I could go was the local Ace hardware. Bought a 3/8" x 1" square head setscrew and used that. Think I got a good repair!
Thanks for the help!
Developed a leak on a port on the side that looked like a threaded rod with two jam nuts on it.
Took the risk of taking it apart without a service manual, which I would have dearly have loved to have had. Turns out the port is indeed a pressure relief valve. The bottom nut is the valve body which holds the spring that holds the ball valve shut. The threaded rod is a 3/8" x 1" coarse thread setscrew. (Think of a common setscrew like you would find on a v-belt pulley, only longer.) The top jamnut is actually a nut with a plastic insert/washer which forms a seal at the top of the valve body. That setscrew, which had a hex shaped hole recessed in the top had snapped off right at the junction of the valve body and the jamnut - this allowed fluid to escape past the threads, go through the crack, and leak into the recessed hex hole in the setscrew. Craziest thing I have seen in a long time!
On a Sunday, only parts place I could go was the local Ace hardware. Bought a 3/8" x 1" square head setscrew and used that. Think I got a good repair!
Thanks for the help!
