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Cat-426 LoaderBackhoe "No-Cabin-Heat"

Discussion in 'Tractor/Loader/Backhoes' started by fitterski, Nov 10, 2019 at 1:10 AM.

  1. fitterski

    fitterski Member

    Joined:
    Dec 3, 2018
    Messages:
    22
    Occupation:
    retired
    Location:
    quebec
    Days before the first snow I just discovered that the CABIN heater is blowing cold air only, the machine is #7BC01181, this is the early series built in England with a Perkins engine. I've read the 416 heater thread as I am just starting to TS this.

    - The pro who installed the engine (I built) also installed a circulation engine heater in-line in one of 2 hoses going from the lower right rear of the block, over the engine to the Cirtc-Heater output, then input, then to the left rad lower hose as one of also 2 hoses connected there to the large rad hose. The Circ-Heater did a meltdown so he gave me another to install, it also started burning out so I pulled it, joined the hose ends with a piece of pipe. All in all the exercise if futility cost me like $400, my hunch is that the routing simply is no good for this type of heater, and that it simply wasn't convecting at all.

    - Last winter the CABIN heater was heating OK.

    - There is a dual hose leaving the block at the right rear and that fitting looks like an F and has a T-handle valve. The different front left rad lower hose connection also has 2 hoses leaving, no valve there though. I don't think I ever closed or opened this valve, it's pretty inaccessible from the right front engine bay opening as well as from underneath (shame on Cat!)

    - Turningthe Temp knob has no effect

    - I can't find anything in the manual about the cabin heater, and the hose connections and routing are extremely hard to see.

    Tomorrow I'll take some pics and try to get a little more eyes-on.
     
  2. Delmer

    Delmer Senior Member

    Joined:
    Jan 4, 2013
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    5,593
    Location:
    WI
    Tank "circulating" heaters need to be installed so the coolant can circulate by convection as you stated. no pumps involved. they typically have little check balls in them to stop backwards flow when the engine is running. They also have thermostats so they shouldn't melt even if they're not circulating to the engine. I'd have to see a pic to see what was going on with the heater instal, but that's gone so on to the other issues.

    The valve on the block has to be open for the heat to work. IF there's a coolant valve inside the cab for temp control, that has to be open. The coolant has to be full enough to circulate through the hoses and heater core. With the engine warmed up after working, the heater hoses should be hot to the touch all the way to the cab and back, if they're not, then find out where they're plugged. Heater core could be plugged also.
     
  3. Tinkerer

    Tinkerer Senior Member

    Joined:
    May 21, 2009
    Messages:
    3,849
    Location:
    On A Riverbank in IL. USA
    Delmer is absolutely correct, the flow in coolant heaters is directional specific. Mine is. The flow direction is permanently marked by the hose connections, in and out.
    It heated the engine coolant just fine with the engine off.
    I had heat in the cab until I started the engine, then there was no any heat in the cab.
    When the engine was running the water pump was pushing against a built in check valve in the coolant heater.
    I reversed the hoses and had heat in the cab immediately.
    Your coolant heater melt-downs may have been due to trapped air in the lines.
     
    Last edited: Nov 10, 2019 at 2:26 AM
  4. fitterski

    fitterski Member

    Joined:
    Dec 3, 2018
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    22
    Occupation:
    retired
    Location:
    quebec
    RESOLVED

    When the pro installed the circ-heater for the engine he inserted a T between the block and the right-rear block valve and another one at the lower rad fitting essentially setting up a parallel hose to the cabin heater hoses. With the new line looping vertically over the engine I don't see how this could have ever worked without being air trap. I don't know how it could/should have been hooked up, maybe routing the hose under or behind the engine..

    He told me he had installed a valve so as to close the circ-heater line in summer, but he didn't. Then when I removed the circ-heater in the spring I closed the valve thinking it was for IT and not for the cabin radiator. I got away easy with this one, after opening the block valve to close the ticket I also separated the surviving circ-heater hoses and plugged them up..

    Thanks for chiming in guys! I'll ask the bartender to say a mass for you souls.
     
  5. Tinkerer

    Tinkerer Senior Member

    Joined:
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    Messages:
    3,849
    Location:
    On A Riverbank in IL. USA
    Good job of figuring that one out.
    I think you need a new name for your "pro" ! That could have been a costly mistake for someone who couldn't determine how he screwed up.
     
    DB2 likes this.
  6. fitterski

    fitterski Member

    Joined:
    Dec 3, 2018
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    22
    Occupation:
    retired
    Location:
    quebec
    No flash in the pan, but out here in the sticks we have little choice, and I might add it's almost a 'generation problem', the old salts are dying off. There WILL be other issues I'm sure as I'm just preparing for the shakedown of season #11 with the 426 and its snow-blower. I put studded chains on the rears and a 1200 ft-lbs rubber coupling on the blower impeller.