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BFL13's avatar
BFL13
Explorer II
Sep 07, 2018

460-7.5 Coolant Hose Back of Engine Question

Trying to identify two hoses in the Class C where both are holed but only one leaks. (Had to stop from overheating, and eventually found the leak-- got towed to destination, now to fix it and get home -one hour drive)

Sorry-no pictures till after I get it home with temporary fixes.

Doghouse removed, on the passenger side back of engine above transmission and going back out of sight under the floor, there are two long rubber hoses coming from higher on the right front side. Both same size about 1 inch outside dia. with inside diameter 5/8 and take a copper 1/2 inch pipe that can be clamped as a repair.

At floor level, these two hoses are just above the two hoses that go to the catalytic converter (removed last winter).

One was leaking coolant from a hole burnt out where the two hoses were on something hot just back out of sight under the floor, perhaps the exhaust, but maybe where I had a problem a few months ago with another pair of pipes close by that went to the catalytic converter. That got fixed, but it seems these two other hoses were damaged then or since.

There is some slack in the two hoses so you can pull them up enough to do the repair.

I cut away the damaged part of the leaking hose and did a repair with copper pipe and clamps so that should get us home,(with added coolant top-up) but what about that second hose right beside it with a hole in it that is not leaking?

Obviously I can do a similar repair of that hose, but do I need to? What does it do?

I also have to figure out a way to keep these two hoses clear of whatever they were lying on that got them so hot and burnt holes in them.

Thanks.
Class C
  • donn0128's avatar
    donn0128
    Explorer II
    Sep 07, 2018
    For a temp repair, take a short piece of heater hose and simply loop between the two, inlet and outlet on the motor end. Secure with hose clamps, fill with coolant and drive.
  • BFL13's avatar
    BFL13
    Explorer II
    Sep 07, 2018
    ronfisherman wrote:
    Hoses may go to coach water heater


    Yes , it does have a heater somewhere (that uses engine heat) for the RV part with two small air registers in the back. There is an under dash switch to turn their fan on with ?three? speeds. (left side of steering) I have that switched to off. This is independent of the RV furnace heating system.

    I have the two hoses that look the same side by side, but hot coolant only coming out of one of them although both have holes in the same place where they were on something hot (exhaust pipe?) the other hose is empty with the engine running.

    The water heater for the Rv is an Atwood propane-only type. AFAIK it is not involved with the engine cooling system
  • BFL13's avatar
    BFL13
    Explorer II
    Sep 07, 2018
    Googling a bunch, I find that there is a pair of hoses going to/from the " rear heater" and somebody got at his by lifting the doghouse.

    Why would one have hot coolant in it and the other be empty in my case? Or do I just have to wait longer after starting the engine to get water out the other? The rear heater is not "on" by the under-dash switch, so does that stop the hot water from going through the core and that is why the second hose is empty?

    If the one hose did not have that hole in it, would any hot water be in that hose?

    So it appears the second hose does need to be repaired too if it is part of a circulation. I will do that.
  • jamesham's avatar
    jamesham
    Explorer
    Sep 08, 2018
    I had a Brougham Class C motorhome on a Dodge Chassis that had rubber heater hoses going clear to the back 6 gallon hot water heater. There also was a small heat exchanger (small radiator) back there in the same place. Engine coolant circulated back there to provide domestic hot water while en route without burning any propane. My bet is your unit has something similar.

    It was a great idea, but poorly installed. The rubber hoses were not protected and burned by exhaust, and punctured by rocks. You have coolant coming out of one hose that is going TO the rear. Since nothing is reaching the rear, nothing comes out the RETURN hose.

    Even after replacing the factory sloppy install with rear pipe, the system left much to be desired. The water temp was unregulated, so the water heater might produce scalding hot water after a long drive. The small heater radiator had no fan, so produced very little heat in winter. But in summer, it was a hot spot exactly where and when no heat was needed.

    I ended up slicing the hose by the engine and installing a water shut off valve in the out line to the back. This stopped any possible leaks, and only provided heat when needed in winter.
    jim

    BFL13 wrote:
    Trying to identify two hoses in the Class C where both are holed but only one leaks. (Had to stop from overheating, and eventually found the leak-- got towed to destination, now to fix it and get home -one hour drive)

    Sorry-no pictures till after I get it home with temporary fixes.

    Doghouse removed, on the passenger side back of engine above transmission and going back out of sight under the floor, there are two long rubber hoses coming from higher on the right front side. Both same size about 1 inch outside dia. with inside diameter 5/8 and take a copper 1/2 inch pipe that can be clamped as a repair.

    At floor level, these two hoses are just above the two hoses that go to the catalytic converter (removed last winter).

    One was leaking coolant from a hole burnt out where the two hoses were on something hot just back out of sight under the floor, perhaps the exhaust, but maybe where I had a problem a few months ago with another pair of pipes close by that went to the catalytic converter. That got fixed, but it seems these two other hoses were damaged then or since.

    There is some slack in the two hoses so you can pull them up enough to do the repair.

    I cut away the damaged part of the leaking hose and did a repair with copper pipe and clamps so that should get us home,(with added coolant top-up) but what about that second hose right beside it with a hole in it that is not leaking?

    Obviously I can do a similar repair of that hose, but do I need to? What does it do?

    I also have to figure out a way to keep these two hoses clear of whatever they were lying on that got them so hot and burnt holes in them.

    Thanks.
  • BFL13's avatar
    BFL13
    Explorer II
    Sep 08, 2018
    Thanks.
    Good explanation of why the second hose seems empty!

    That fits with what the other guy did with his, which was to cut both lines where he could see them under the doghouse, and cap the two hoses going to the back and joining the two from the front. That eliminated the rear heater.

    I would just repair the two hoses and leave as is except to try to keep them off the hot exhaust. Your solution makes sense too.
  • jamesham's avatar
    jamesham
    Explorer
    Sep 08, 2018
    Your situation kind of reminds me of my Dad's old cars of the 50's before air conditioning or motorhomes. The coolant circulated thru the under dash heater and produced some heat even in summer with the fan off and vents closed. The DIY solution then was an inline water valve (sometimes controlled by an extended push wire) that stopped ALL coolant from entering the car interior.

    When I had a similar heat situation with my motorhome many years later, the same inline water valves were STILL available at auto parts houses. I replaced the lousy factory installed rubber hose with copper pipe covered in foam home plumbing insulation and screwed with plastic hangers to the bottom of the RV floor. I did a lot of work before I decided the whole idea was not needed and eventually replaced the old water heater with a new gas/electric model with direct spark ignition; no pilot light. If you have a switch to turn a fan on/off, it may be nice to have extra heat in winter.
    jim
  • BFL13's avatar
    BFL13
    Explorer II
    Sep 08, 2018
    I will be back to the RV on Monday to finish the repair and drive it home. At least now I know (I hope!) what needs doing. Fix both hoses. I will leave the doghouse off for the trip home so I can see if my fixes are holding.

    If I have time, I could maybe try it with the one hose fixed that was leaking and see if water now does come out the other.

    ISTR one of the pamphlets was about a rear heater or it might have been in the "incomplete truck" manual so there might be some plumbing info there.

    Some time ago I did try that under dash switch for the rear heat, engine running, and did get hot air from the two little registers back in the RV part. That just helps keep the RV part warm while you are driving. Normally the furnace would be off then.

    I will post a follow-up.
  • pianotuna's avatar
    pianotuna
    Nomad III
    Sep 08, 2018
    Hi BFL13,

    Fix them both. Doing such a repair on a hot engine on the edge of the road may not be a wise choice.

    Have a safe trip home.
  • BFL13's avatar
    BFL13
    Explorer II
    Sep 08, 2018
    The RV is at a friend's place where we were going when it happened. Good Sam tow. Gottaluv Good Sam! (Unless they kick me out for being a nuisance)

    The one hose is already "fixed" so water should come out the other soon after starting while still there. I will fix that hose before leaving, and I have water if it still leaks. I can watch for a while to see if any leaks before heading home.

    When I first called Good Sam, I had not found the leak, nothing showing up front, but while waiting for the tow truck in a Rest Area we pulled into, I took the doghouse off and there it was.

    It was a DIY level repair so I changed the tow job from going back home to going ahead to the destination so we could still do the dog event. I don't get another free tow from there to home, so a risk taken, but low risk (we will see how that works out!)

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