Trash pump won't prime?

Discussion in 'Mechanic and Repair' started by Bunton Guy, Dec 27, 2005.

  1. Bunton Guy

    Bunton Guy LawnSite Bronze Member
    Posts: 1,756

    Bought a new 5.5 honda trash pump..engine runs great but the pump dosent actually pump anything???

    So I took the hose (intake) sealed the intake that makes contact with the quick disconnect with gasket maker so their is NO leaks in the intake line.

    I then prime the pump as per the directions.

    Put the suction end down in water roughly 2 feet from bottom so there is no clogging issues.

    Still to this day it never pumps water it only pumps out the half gallon that is in the pump that I had to ' prime ' the pump with!

    I can't dissasemble the pump because all of the rubber seals have ....well sealed themselfs from me prying the pump apart to check any seals.

    I have infact been able to get the trash pump to pump water once when I took a 275 gallon toat I had in the bed of my truck and filled it with water. Hooked the intake of the pump to the outport of the 275 gallon tote in the truck and let the valve open. Primed and started the pump and she pumped like a champ but ONLY because it is basically being force fed from a large tank.

    Still can't get it to create any type of suction once the intake hose has been placed in pools,ponds etc...????

    Any ideas guys?
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    Well, your going to have to get that pump opened up and clean all the seal surfaces and replace all the seals, Check the impeller wear ring for groves wore in it and reassemble with some type antiseize lubricant which will aid in sealing and keep corrosion down and make it easier to tear down the next time. Also if there is any water leaking between the pump and engine the mechanical seal needs replaced also.
  3. Bunton Guy

    Bunton Guy LawnSite Bronze Member
    Posts: 1,756

    I checked the oil thismorning and it was milky!!! so I replaced the oil, im guessing thats the mechanical seal??

    Is there a soarce online to get these seals?
  4. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    It could very well be the mechanical seal letting water into the crankcase even though the engine has it's own seal, I have seen this happen a few times in the past. As for on-line parts I don't know I entered Honda Pumps in the browser and came up with many matches, You may give that a try.

    Good luck
  5. Dirty Water

    Dirty Water LawnSite Fanatic
    Posts: 6,799

    If its brand new, why not return it?
  6. lawnmaniac883

    lawnmaniac883 LawnSite Silver Member
    Posts: 2,613

    Out of curiousity here, by trash pump, do you mean water pump?
  7. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    Yes it is a type of water pump, But is called a trash pump because it is heavier built and has a heavy duty impeller for pumping sticks, rock or trash that may be in the bottom of a pond, ditch or what have you. A standard water pump would be torn up in nothing flat if used to pump trash.
  8. xcopterdoc

    xcopterdoc LawnSite Senior Member
    Posts: 752

    You might want to check the flapper on the inlet. This acts as a check valve. If its not that, it might need to have the impeller shimmed closer to the volute insert. When I worked in the rental industry, we would get new ones that wouldnt prime... we reshimmed the impeller and all was well. Also make sure you are using a hard wall hose on the suction side. Another note... Honda makes different grades of these pumps... some are homeowner jobs with plastic impellers and pump hpousing.. these are meant for WATER only.. then they have the trash pumps with metal impellers and housings. The plastic ones wont take much in the way of trash to destroy it.
  9. Gravel Rat

    Gravel Rat LawnSite Fanatic
    Posts: 9,544

    How many feet of lift do you have to suck the water from a 5hp pump is a baby so its going take a bit to get it started. The pumps we use on Barges are usually 11hp some a 13.

    The way I get scow pumps going is fill them up with water start them up and leave the cap off and use the palm of my hand to act as a valve letting some air in. Once it starts to pump a little I put the cap back on loosely letting some air in then once its going stong then tighten the cap up.

    Oh ya you can give the engine a little more throttle by reaching under the fuel tank and pushing the lever so the engine revs up a little higher.

    You can't beat the Honda pumps they start everytime they rarely break down. Some of the pumps used on scows (barges) the frame of the pump is rusted off the housing is rusted but they still work they look like crap but run good.
  10. Bunton Guy

    Bunton Guy LawnSite Bronze Member
    Posts: 1,756

    What is the best way to break into the pump housing to get the impeller off to shim it? how many shims? There is such a suction I had all the bolts off of the entire housing and even a 12" screwdriver and rubber mallet wouldnt break it loose. I can't find anyone on the net that sells the seal kits for these honda 2" trash pumps.

    My inlet and export hose are both of the same material that braided 2" hard line. Its green and northern tool sells it.

Share This Page