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Hydraulic pump

Discussion in 'Residential Snow Removal' started by john_alaska, Mar 16, 2013.

  1. john_alaska

    john_alaska Junior Member
    Messages: 22

    I took the plow motor off to bring in for amp test. How easy should the shaft turn on the hydraulic pump? I cannot turn it by hand, but I can turn it using a pair of pliers.
     
  2. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,980

    if theres no fluid in it,,easy just take to 2 bolts off and pull it out
     
  3. john_alaska

    john_alaska Junior Member
    Messages: 22

    I had the motor tested off the plow and the shop said it was in v-good condition so since the pump was the only thing left, I replaced it and changed the fluid.. easy fix other than the $200 for the pump, yuk... back on track and works like a charm, ready for the next snow..
     
  4. jb1390

    jb1390 Senior Member
    Messages: 710

    What is different after the change? Did it solve any symptoms you were previously experiencing?
     
  5. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,980

    I would say it was the pump. Since he also said it works like a charm now
     
  6. jb1390

    jb1390 Senior Member
    Messages: 710

    What was his symptom before? Last I knew, the only thing wrong was that the battery died........
     
  7. john_alaska

    john_alaska Junior Member
    Messages: 22

    basically with the bad pump the amp draw would drain the battery. Back to normal now...
     
  8. jb1390

    jb1390 Senior Member
    Messages: 710

    Have you plowed with it since for a decent period of time?
     
  9. john_alaska

    john_alaska Junior Member
    Messages: 22

    I ran the driveway last night for a test pushing back berms, been so cold here the snow has been frozen soild and tough on the plow so will wait for melt or another snow... but did get to work the plow enough to purge the lines and get fluid level corrected...
     
  10. jb1390

    jb1390 Senior Member
    Messages: 710

    So you replaced the pump, and haven't subjected it to conditions that caused your original symptom. The plow seems to function identically to how it did before for short durations.

    Next time it snows, bring your jumper cables..............

    Here are my thoughts quickly. If the pump had so much resistance that it was causing undue strain on the motor:

    1. There is no way it also would have had enough power behind it to lift the blade with all that extra resistance, it would have stalled out.

    2. It would have killed the motor due to excessive heat and load.

    I don't think your problem is gone, unless you solved it inadvertently while replacing this part.

    Hope I'm wrong for your sake, let us know after you've used it for a storm.
     
  11. jb1390

    jb1390 Senior Member
    Messages: 710


    Oh, and remember that thing I said in the other thread about who's advice you heed, sometimes the misbehaving get let out of time out.
     
  12. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,980

    I say its fixed.
     
  13. jb1390

    jb1390 Senior Member
    Messages: 710

    Based on what? He replaced a random part on a hunch, with no testing. He took the motor off and had it tested, instead of testing the thing as a whole, which might have told us something partly conclusive.

    There was no reason to think that the pump was bad, besides a hunch based on symptoms that point more strongly to a bad ground somewhere he hasn't found yet. (alternator to block for example)

    How would you explain, if the pump was causing such an excess load on the motor, that the plow still lifted, and the motor did not overheat?

    If the charging system is working 100 percent, and the battery is draining, all that energy has to go somewhere. It would have killed the motor.

    So what's your logic for thinking that the pump was bad, and that the new one is fine?

    BTW, I don't care if I'm wrong, I want the OP to have his truck functioning normally and not break down, and I don't think the problem has been solved yet.........
     
  14. jb1390

    jb1390 Senior Member
    Messages: 710

    John,
    you remember the electrical measurements you made and posted in the other thread?

    Would it be possible for you to repeat those tests-only this time, do them with the truck running, and have a partner (that you trust) hold the plow at full angle (either way is fine), running up against the relief valve? Make sure they don't accidentally go the wrong way and pinch you against the bumper........

    No need to take the first measurement (truck not running), but post the other 3 when you get a chance.
     
  15. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,980

    First. I nor you are there and don't know 100% the issues

    He said he couldn't turn the pump by hand but could with pliers. So that tells me that the pump is HARD to turn. But still does. So if he's playing with the plow its Gunna drain the bat. And the alt ain't Gunna be able to keep up with the drain. Im sure the motor got warm,,,,but what's the spec for temp on a plow motor?
     
  16. jb1390

    jb1390 Senior Member
    Messages: 710

    John,
    Is the new pump significantly easier to turn than the old one?

    To compare you'd need to ensure they are both full of oil, so you'd have to take the motor back off.

    I don't recall on my unimount that I ever tried to turn the pump, but I wouldn't be surprised if you can't turn it by hand.

    If it turns easily, and far different than the old one, I might jump on the "it's fixed" bandwagon. But I don't think it will be.
     
  17. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,980

    ok here goes the long explaination

    lets say that there was a restriction in the pump (just agree for now this will help with where im going)
    now, since I never got an answer to the pump psi this is where im basing my fact.
    the motor don't know that there is a restriction, neither does the pump. so when you raise, its trying to spin and the pump is working but theres resistance.
    if the pump is worn and not making full psi, your going to overwork the heck outta the motor everytime to get the plow to respond
    now you can electrical test 7 ways to sunday and it will only tell you that there is excessive draw. the motor will get hot, and the batt will go dead and the alt will barely keep up. just b/c the motor gets hot doest't mean its shot.
    every plower uses there stuff till it wont work anymore. im betting that he used it till the batt ran dwn to no volts and the alt just couldn't put enough back it.
    you also got the volt test answers,,,but never got the amp test answers (as far as I know an on the tk test never was done)
     
  18. john_alaska

    john_alaska Junior Member
    Messages: 22

    I brought the motor to an electrical shop and after inspection and draw test of 60 amps they said the motor was fine. Now, the old pump I could not turn the shaft without putting a wrench on it to turn.. The new pump I could spin the shaft with my fingers.. Basically the old pump is seized-up... so going about this all backwards; I just placed an order for a clamp-on DC amp meter for the tool box... I will then be able to test the plow motor draw for lift, right and left turn... when it warms up, I will pressure test also just to see what i get,
     
  19. jb1390

    jb1390 Senior Member
    Messages: 710

    I think you may not have been able to turn the old pump because it was full of oil and building pressure.
     
  20. dieselss

    dieselss PlowSite Fanatic
    Messages: 10,980

    Still should be able to turn the pump by hand both ways