MCI 102A3 - coolant pump information needed (and how to add coolant?)

[Scott & Heather]

Interesting Adam. Our 102C3 of course now has Renaissance caps so it's now a "flat back" with a normal radiator fill cap up top to the side. Cool.


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[jav9956]

Why are you not a fan of the auto refill?  Seems like a nice feature.

And did you rewire the entire system to 12V, or just the coolant pump?  And if so, are you running 12V from the battery bank all the way to the back of the bus just for this pump?

It is one more thing that can break... and when it does there is not an easy way to refill the cooling system so you have to go through the timely and potentially costly repair procedure before using it again. I would rather just have a fill cap that is easily accessible and be done with it!

But here is an idea. How about splicing one of the lines that lead from the surge tank in order to install a fill cap should you be in a position that the recovery system does not work but you need to top off the system? The main issue is knowing when it is full and/or not putting air in the system. You can easily install a "sight" by having one small section with clear tubing towards the top but you open yourself to a location of potential leaks.

Just a thought, I will ponder some more.

[buswarrior]

These systems arrive failed because the coach has been in the hands of paid help who did not care, chose to not understand, thought it was funny to just switch it on and leave it run dry until it burned out, put some less skilled person to try to fix it, made it worse, gave up, sold coach....

Once it has been put right by the busnut, who has a vested interest in using it correctly, it will do the job as it was engineered to do, safely at ground level.

Every old guy I know who fell off a ladder, wishes he hadn't. Reduce your exposure!

The access door you would need to cut to do it manually will be right up at the clearance lights, centre back, get your taller ladder, your multiple pails of coolant, a funnel that will work horizontally while you try to pour... and cut it, brace the hole, install a hinge, a method of closure...

The stock system is simple. A lower tank, a common DC water pump, some coolant lines, a switch and some wire.

happy coaching!
buswarrior

[jav9956]

That makes sense... I just need to locate and replace the pump now!

[bevans6]

Some MC-9's, maybe most, have a 12v source on stud 41 in the rear junction box.  The pump injects the coolant directly into the coolant return plumbing from the radiators to the water pump through a remote check valve.  Since it is supplied from the reservoir which is completely separated from the working cooling system with check valves, the pump will normally not see engine-temperature coolant at any time, just ambient temperature (unless it gets some coolant pushed down to it past the 7psi check valve on the line to the header tank).  The schrader valve that comes down from the middle of the header tank is the level check device, you could add a bit of clear tube and make a visual sight gauge there if you wanted to.  Neat system, I wonder how they automated it.

Edit:  this forum is a dangerous place!  Now I am thinking "why not build a mount for a 5 gallon pail of oil where the ac compressor used to be with a little electric pump and tap into the oil pan so you can fill your engine with oil by flipping a switch instead of getting out a hand pump, a funnel, a little table to put the oil pail on, and cleaning up all the oil that spills when the funnel slips"

[MB LeMirage]

My Prevost has a remote oil tank just for that. Gravity fill from the resevoir to a ball valve at the block, easy top ups.
Ryan.

[jackhanow]

For something like that I would just make it work with a jump box. I have a 50 foot extention cord. I put alligator clamps on one end and a heavy duty power port on the other. Comes in handy.

[AdamWalkup]

The system of a lower tank and a pump to refill to the top is a good idea, and is much easier in commercial service then having a driver in a clean white shirt and tie standing on a ladder in the parking lot at 3 am trying to poor coolant above his head.  However I don't like the "auto" refill system for 2 reasons: it always refills when the coolant starts to cool, which always happens about 4 am after running all day, and it wakes me up and every time I wonder what that noise is for about 10 seconds.  The other reason is if the lower tanks is not full the pump could run until it damages something (the pump).  I also want to know if the coolant level is going down, which I would not know if it pumps automatically.  I'm happy getting 12 volt power in the rear J box, and installing a cheap water pump.