Grant Eckard
New Member
Hello, I've got an old 490d on my farm and it's been having hydraulic issues. The machine bogs down and starts billowing smoke when you try to run it. If the controls stay below half stroke it seems to run a lot better and the rpms keep up the second you call for full stroke it bogs the motor down and the hydraulics barely move. I had the dealer come out and test the system which showed a spool on the main pump was sticking. He told me to pull the cap off the top and see if they move up and down easily. The one closest to cab moves up and down fairly easily but the one towards the counterweight is quite stiff. Dealer recommended removing the spools and polishing with scratch cloth until they move freely and see if that fixes it (its an old farm machine, I'm not going to dump a bunch of money into a new pump). My question now is how do I get the spools to come out of the housing without breaking them. I tried pulling them up but they only get so far and then both stop in the same spot. My next thought was to carefully remove the block off the bottom and see if they will free up or slide out from the bottom. Any help would be greatly appreciated. Excavator hydraulics are way out of my wheel house.
