Hello Folks, I'm new here and I got a question I hope someone can help me with. I have a 1987 Deere 490D excavator, and the problems I'm having may be related to the pilot controls pump. I have cleaned out the old pilot filter and found quite a bit of steel shavings in it, I have looked online and found a blow up of the main pump device [uchida hyramatic #A8V55ESBR] which shows the pilot gear pump inside the bell housing of the unit. What I am not sure of, is where the port to test the pressure is located, and what the pressure should be. The local JD dealer has not been terribly helpful, I guess they are busy with bigger fish than me, as I can't even get them to answer such a simple F#$% question!! Hopefully someone here might be able to help. They told me the price of a new pump and I think I've got it figured out how to change it, but it sure would be nice to know if that really is the problem or not! Any help will be greatly appreciated, Thanks! Carl B.
You may have bigger problems than just the pilot pump, have you inspected the main return filters for metal, either steel or brass? I believe the pilot pump suction is open to the main pump case, they all have one big common suction line from tank. If one of the main rotating groups is throwing metal from a gear or bearing it should show up in all the filters. I can't say where to check it but I think the pilot pressure is about 600 psi, mebbe one of the resident Deere or Hitachi gurus will chime in.
Thanks for the reply, I haven't cut the main filter apart yet, I guess that's next. We did take some lines off that had small screens in them and didn't see much crap in them, but then again I guess it don't take much to screw things up! I hope the gurus you've mentioned will shed some enlightenment on me, I sure don't seem to be getting much help from the folks around here! [Marquette mich]
Don't expect any from Deere. I have yet to find an industrial Deere dealer that is worth the air they breathe. Nothing but moan and complain and want to just photocopy pages out of the manual anytime you try and ask anything. That, and about 1 time out of 10 you'll actually get a salesman on the phone when you call. JMO.