MCI 9 Drivers OTR Heat

[Kenny]

If I remove the OTR main heater core (the big heater core from inside the baggage compartment), plug the ends of the lines that went to it, shouldn't the drivers OTR heat continue to work? And yes I did turn the valves to and from the engine back on.

Kenny

[bevans6]

I think it's in the same loop as the main core.  You could connect the two lines together rather than capping them, maybe.  I know the main heater line tap in the passenger side engine bay (near the electric heater valve) controls heat to both the drivers heat and the main heat on my MC-5C.

Brian

[MC8Mike]

Yes you can plumb it so the drivers heat and defrost still work. I did away with the coach heater core and evaporator and put a RV basement A/C unit in their place but kept the drivers heat functioning.

[Kenny]

Is it as simple as removing the OTR main cabin heater core and plug the lines that went to the heater core? This is all I've done and it seems I have no water flow to the drivers heater core now.

[robertglines1]

two things.. main heater core might be required to stay loop (bypassed on MCI)Its been awhile since I bypassed one on a MCI;also ck to see if you don't have a in line solenoid to release water to the drivers/defroster.you might have to put a switch on it to bypass the.(    pedometer(Sp) control circuit..look in ceiling of spare tire compartment. or along side front defroster core..also ck to see if you have a water pump to help water flow;would be electric in line pump...good luck...

[buswarrior]

The defroster and the big heater core were plumbed in parallel.

So, as long as you terminated the big heater core at it's spur lines, and didn't cut off the main pipes...

Bleed the defroster core at the screw at the top of it, it'll be air-locked after you had the system opened up.

Everything should work as stock after that.

What did you do with the control valve from up high in the first baggage bin?

happy coaching!
buswarrior

[Kenny]

Buswarrior thanks for your info. Normally I don't post many questions without going through a search of the board first along with studying the bus manuals. Thought it was parallel piping and all should have worked. I'll bleed the drivers heater core this week and post an outcome. As far as the control valve goes, its still there and I've not made up my mind to remove it yet since I may use it later for another hair brain scheme I have. Again Thanks

[Lin]

I guess the 9 is done differently than the 5a.  I have removed the OTR cores, closed the valves and plug the lines.  The driver's heat is piped separately so is not affected.  Although I do not know how it would be done, but I have wondered if the old OTR heat lines could be used to install an extra radiator should it ever be wanted.

[buswarrior]

Yes, Lin, an excellent opportunity to do just that.

With all the gyrations that busnuts go through to try and cool an MCI, why we don't hear about more projects of reworking the heater core and using it as another radiator...

You figure how much heat could be dumped overboard mounting a supplemental radiator in place of the AC condenser...

happy coaching!
buswarrior

[Kenny]

That's part of my hair brained scheme. Add a radiator in the spare tire compartment. Force feed air from the front of the bus through intake grates, through the radiator and then down under the the bus. Use the existing OTR main heater water control valve to enable supplemetal cooling without additional electric fan loading.
Kenny

[ttomas]

 On a 1983 mc9, I removed the heater core and tied the hoses from each side together in order to keep the flow of things going. I also incorporated small radiators throughout the coach for heat while traveling. I may be wrong, but my visual investigation, while we had the floor out, found that capping the ends stopped the flow.  its been a few years since.
hope this helps, Tom

[Michael Mc]

My MC5B has a hand valve to the left of the driver's seat at floor level that kills the water flow to the driver's heat/defroster.  Handy to know in the heat of the summer.  Found that one after all the sweat from inside me was outside me.   

[Lin]

Tom,

I would guess that closing the valves, as we've done, already stopped the flow.  Capping the ends just avoid drips if the valves happen to leak.  Is there anything negative about stopping the flow if one is not using it as you are?

[ttomas]

I think you will be okay and it seems to be the consensus here as well.
Tom

[niles500]

Kenny - Excellent idea - Don't forget to post the outcome - thanks