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Kohler 15 Command Pro/AR pump washer 4ga 4k

Discussion in 'Mechanic and Repair' started by Kewadin, Aug 14, 2012.

  1. Kewadin

    Kewadin LawnSite Member
    Posts: 14

    I had my exhaust pipe break off just past the head and I didn't know it till I had quit washing. It might have ran for over 1 hour at near wide open. Could that have done valve damage causing loss of power? The motor sounds good but when I crank up the pressure it labors hard and the old power the pump used to deliver isn't there any more. I thought it was a pump problem and I cleaned the pump valves and unloader but still have the problem....I didn't think I could have damaged the motor so bad, sooo, I'm here asking for help from someone that knows more than I do. Thanks in advance.
     
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024


    A leak-down test or even a compression test would tell the condition of the valves.....

    Are you depressing the wand trigger (water spraying out of wand) while cranking up the pressure ?
     
  3. Kewadin

    Kewadin LawnSite Member
    Posts: 14

    I wired the gun trigger open, started it up at min pressure and cranked it up to max pressure. It has a lever action throttle and I usually run it wide open and adjust pressure (almost always max). I think it has a governor but at WOT it doesn't look like it can affect the throttle? At first I thought it was the pump,then I thought governor,but now I'm thinking loss of power at the motor..I have misplaced my little compression test kit. But when I find it,what pressure should it make? What pressure should make me pull the head? The unit is 10 years old but I doubt it has much over 100 hours of work. It was always really hard to pull start (no electric starter) and now I'm thinking I can pull it a little easier now? Thanks for your help.
     
  4. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024


    Below 80 lbs.....

    Can you post the machine brand and model numbers AND the AR number off the pump ?

    I'm thinking you have a unloader issue, Cleaning doesn't help weakened springs and worn seats.....
     
  5. Kewadin

    Kewadin LawnSite Member
    Posts: 14

    I hope it's the unloader. I'm waiting for one in the mail. I took apart the old one and really gave it a good cleaning and it didn't make a difference. Can a bad unloader cause heavy loading of the motor without making pressure and volume? ....I hope the motor is OK. The washer is a Porter Cable PCK4040SP. The pump is AR RKV4G40..(4gal. & 4000psi @ 3400rpm). The unloader should be here soon and I will post my results .
     
  6. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024


    Yup, Sure can......
     
  7. Kewadin

    Kewadin LawnSite Member
    Posts: 14

    I put a new unloader and a pressure guage on the washer today. I adjusted it per the instructions but the highest pressure I could get out of it was 2000psi.It didn't take more than a few turns of the adjustment screw to get 2k but that was it. The motor seems to be laboring hard too. I kept turning the adjustment past 2k and when I release the trigger it kills the motor on a pressure spike. So I set it just under 2k and and it spikes about 200 psi but the motor keeps running. It will work as a 2000psi washer but it should be 4000psi. I need to check the motor compression before I do anything else. I will post back when I get my hands on a compression tester....
     
  8. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    Replace or try another spray tip in the wand, Over time the tip hole wears larger and drops pressure. Trying to raise pressure at the unloader with a worn tip can cause engine labor.....
     
  9. Kewadin

    Kewadin LawnSite Member
    Posts: 14

    I finally found my test kit. It's like new and seemed to make a good seal. It made 50psi cold and 60psi warm. I did it with the throttle wide open and the air cleaner off. It's only making half power,do you think it's because of poor compression? How bad is it? Is it time to take the head off? Thanks for any advice.
     
  10. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024


    That's pretty low..... Need to pull the head and inspect the bore and valves.....
     

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