Back Heater Problems - Coolant?

[jasphi94]

Hi All! Please help

I'm new to the forum! I have been browsing around and seeing some awesome conversions around here. I purchased a 1997 Blue Bird TC 2000 two weeks ago and have been spending the time to take out the seats, etc.

I wanted to take out the heater in the back and released the fluid from the bottom of the engine. Before finishing to take it out I wanted to go on a ride and when I turned the engine on the "low coolant" light came on. I took one of the pipes going to the back heater out already.

Is the heater system for the back heater connected to the engine coolant or is that a separate circulation? Can I take out the heater entirely and just refill the coolant and have the heater valve that is on the bottom of the engine closed? Or do I need the heater system for the engine to function properly?

[cowlitzcoach]

The heater system does an entire loop from the engine through all of the heaters and then goes back to the engine. There is probably a branch line that goes to the front heaters and defrosters.

If you eliminate any part of the system you will still need to keep the loop intact.

If you turn off only one of the hot water shut off valves, if the system loop is open somewhere it will still leak out of the open end.

Even after you have all of the loop closed up and sealed it will take quite a bit of coolant to refill what was lost. Make sure that as you are adding coolant it is going into the radiator and not just into an overflow reservoir.

[jasphi94]

Originally Posted by cowlitzcoach

The heater system does an entire loop from the engine through all of the heaters and then goes back to the engine. There is probably a branch line that goes to the front heaters and defrosters.

If you eliminate any part of the system you will still need to keep the loop intact.

Does that mean I could just take the heater out and make the loop much smaller, or does the engine need the heater to cool itself down?

[cowlitzcoach]

You can eliminate as many of the heaters as you want. When you do you just make the loop shorter.

There will always be some debate as to how effective it is to turn the heaters on to dissipate excess heat. Without turning on the blower fans I doubt you will make much of a difference. Turning on the blower fans puts a greater load on the alternator making the engine work harder. So again, is the increase in cooling ability offset by the increased load on the engine? I don't know.

The one nice thing about the underseat heaters is they will put out a lot of heat when the engine is warmed up. If you ever plan to travel where it gets cold, like going skiing or running snow machines, having extra heaters during the trip are always appreciated. But if you are always going to head south once the snow flies it probably would be a good idea to get rid of most of the underseat heaters.

[jasphi94]

I see! So in essence the heater in the back is really just a heater for the bus and not a mechanism to cool down the engine?

Thank you very much for your help so far!

[superdave]

Originally Posted by jasphi94

I see! So in essence the heater in the back is really just a heater for the bus and not a mechanism to cool down the engine?

Thank you very much for your help so far!

unless your getting hot or in a situation that will make it run hot. then you want to turn on the heaters and turn your fans on high

[cadillackid]

yes the main purpose of the rear heater is just as a bus heater to heat the interior of the bus. while driving...

if you never plan to have anyone ride back there while you are driving and dont mind that it gets cold then you can take it out... on MOST busses.. there is a connection of the heaters from the driver heating unit that you can take the hoses off that go to the back right where they exit the driver heater and then loop the 2 connections together.. this way you still have the front defrosters and driver heat for when you are travelling...

an added benefit of bus heaters is that they DO provide benefit of dissipating engine heat if the engine cooling system malfunctions such as a bad fan or partially stuck thermostat... however the heaters arent necessary for enbgine cooling.. in fact many people turn off the heater valves under the hood during the warm months of the year to help keep the inside of the bus cooler while driving it..

-Christopher

[Summ1]

Originally Posted by cowlitzcoach

If you turn off only one of the hot water shut off valves, if the system loop is open somewhere it will still leak out of the open end.

I have an International 3000 RE, and I know where one shut off is but I didn't know there were two. Where might I find this?

[cowlitzcoach]

Originally Posted by Summ1

I have an International 3000 RE, and I know where one shut off is but I didn't know there were two. Where might I find this?

Shut offs are in various places on different buses. A lot of times they are dictated by how many heaters/defrosters the bus has.

As to where your heater shut off valves are I have no real idea. I would need to follow the heater lines from the engine to the heaters and back in order to find all of the shut off valves.

[JojoBrisk]

What kind of coolant is best, in your opinions, for a 5.9L Cummins.

[cadillackid]

on an RE emngine you will have to leave the coolant lines that run from the back to the front of the bus or you will permanently disable all of the heat and defrost at your driver seat... sorry i wasnt paying attention when i mentioned you could disconnect those lines.. I was thunking you had an FE bus.
-Christopher

[jasphi94]

Hi All!

Wanted to say thanks for all the help! Just a little update from my side: I closed the circulation again and think that everything should work just fine!

I do have another question though: Can/should I reuse the old coolant?