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Fluid change in unimount pro

Discussion in 'Western Plows Discussion' started by theguynextdoor, Nov 9, 2007.

  1. theguynextdoor

    theguynextdoor Senior Member
    Messages: 307

    What kind of fluid should i be using? I picked up some of the high performance plow hydraulic fluid, but then i saw something about using transmission fluid? I havn't changed the fluid yet. Which should i be using?
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    You can use either one but if you switch from whatever is in it now you need to flush the system very well to get all the old fluid out as ATF and plow oil are not compatible..I usually switch the Uni's over to dedicated plow fluid if I have the system open for any kind of service since they originally came with ATF. Western says the ATF is good down to about 15 degrees but I prefer the plow oil instead since it is more forgiving to any moisture intrusion into the system. ATF has no anti-icing agents in it (why would it need to in a transmission?) Plus when it gets real cold, it doesn't thicken up nearly as much as the ATF does although using synthetic ATF instead of regular dino ATF will help with the cold temp viscosity.

    The only disadvantage of using the plow oil that I've found, is in an older pump that has seen a ton of use and has wear on it is that the thinner viscosity of the plow oil will drop the pump output pressure..sometimes by 200 psi. It not a big deal though,,I usually just give the pressure relief valve an 1/8 turn while I have the motor off while doing the flush..
  3. Philbilly2

    Philbilly2 2000 Club Member
    Messages: 2,163

    I use ATF, B&B nailed it on the head again (what's new) It is good until outside air temp is really cold. When it hits about 0 degrees out, I have to thin my ATF fluid with HEET. Just a little, just to keep the fluid flowing. And, if you are plowing, the constant fluid movement, keeps it usable. I have plowed here when it has been in the negitive numbers, and the only problem I had was I had a valve stick one time. I plulled it in the lot, cleaned it, stuck it back in, topped off the fluid tank, and off I went. Just my $.02
  4. basher

    basher PlowSite Fanatic
    from 19707
    Messages: 8,990

    Hi-performance fluids contain lubricants and anti- foaming agents ATF doesn't have. Uses less amperage and is easier on hydraulic components.

    I would change the system over, it's easy. Just follow B&B's advice.