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Jacobsen hr-5111 users/owners or anyone (Help it keeps overheating!!!)

Discussion in 'Mechanic and Repair' started by greeninga, Jul 6, 2007.

  1. greeninga

    greeninga LawnSite Member
    from GA
    Messages: 81

    I've been having trouble with my unit over heating, I changed the thermostat, put a new belt on, and other things. I cleaned the radiator out that did work but only for a short time. I'm able to get by with it and use it for short durations, but the tempeature still is a little high. ANY SUGGESTIONS on what to do.

    M G
  2. desii

    desii LawnSite Member
    Messages: 193

    What do you mean by "cleaned the radiator out"? I have had the same problem a couple of times and have had to do the same thing....clean the radiator out. By that I mean using an air nozzle from the air compressor (do not use a pressure washer...this will damage the radiator "fins") and blowing out the accumulated grass and debris that are in the radiator fins. Make sure you blow out your hydro "radiator" at the same time. If your hydro fluid is not getting cool enough, this could contribute to your problem.

    Is your hydro tank full? With it being a 20 gallon system, if it's not full, I would think that would contribute to the overheating.

    More importantly, you need to find out why/how you are getting dirt/grass into the radiator in the first place. First, make sure you have closed the trap door (underneath the radiator) after cleaning the radiator area. Second, you need to make sure that you have all of the "foam" pieces surrounding the radiator in place. If any are damaged or missing, you will definitely have problems with debris clogging your radiator.

    I have used regular air conditioner foam and liquid nails for faom to seal mine and have had good luck with it.

    Hope this helps.
  3. txgrassguy

    txgrassguy LawnSite Gold Member
    Messages: 3,083

    These units are famous for minor coolant leaks from the vibration of the cowl smacking the radiator and assembly around.
    Pressure test the entire coolant system and you will find a bunch of minor leaks around the sides of the radiator tank and possibly in the lines running in to the block.
    Bear in mind that the hydraulic oil cooler is part of this coolant system so check the lines here too. Also clean the accumulated gunk from around the hydro tank and filter assembly.
    Eventually what happens is around 4500hrs or so major coolant problems turns in to cylinder head work.
  4. greeninga

    greeninga LawnSite Member
    from GA
    Messages: 81

    I did clean the radiator that way, I even used a coil cleaner. But here is what I found out but can not figure out, heat is being trapped by the hood, when I raise the hood over the engine it does fine it goes back to the temperature it is supposed to be at. So all day today I was running it with the cover off sticking straight in the air and it was doing great. Some how the heat can't leave out of the hood, but it is not clogged or anything. WHAT SHOULD I DO???

    M G
  5. desii

    desii LawnSite Member
    Messages: 193

    Actually, with the hood up, you will be allowing the more debris to get into the radiator. The air doesn't go out of the hood, it's drawn in through it. The fan is actually pulling the air thru the radiator and blowing over the engine. Are you sure your fan is OK? Sounds like you are not getting enough air circulating thru your radiator.

    Did you also blow out the hydro cooler when you cleaned the radiator? Since you have lifted the hood, you are allowing air to "bypass" the hydro cooler and cut in front of it from the top.

    I think your problem could very will be that you have a clogged hydro cooler, which is preventing the air from getting to the radiator with the hood down. JMO.
  6. greeninga

    greeninga LawnSite Member
    from GA
    Messages: 81

    Thanks for the help
  7. greeninga

    greeninga LawnSite Member
    from GA
    Messages: 81

    Maybe because it runs hot when the blades are running
  8. Ironic

    Ironic LawnSite Senior Member
    Messages: 353

    I made hose ends so that I could clean the radiators out with water.
    got a brass 90 degree fitting, adapted it to the hose end, then capped the other end. then drilled a 5/16 hole in the cap.

    the 90 allows you to blow the water straight through, all the way to the bottom. it's regular hose pressure, so it doesn't damage the fins either.
    I've found it to be more effective than air at getting all the crap out.
  9. fixer67

    fixer67 LawnSite Silver Member
    Messages: 2,098

    Dumb question, are you using a 50/50 mix in the radiator? Using straight water or pure anti-freeze/anti-boil coolant just does not work. In fact pure coolant will boil quicker that straight water. It will freeze quicker too. I know I keep saying this over and over but I have lost count of the engines I have seen over heat because of this..

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