How to know when to change coolant - how much is fair price?

[Lowkee]

Hi Friends,

Engine: 1998 DT466E /w that stupid half-radiator/intercooler nonsense.

So I pulled my heaters, looped the lines, and filled up the rad almost to top. Now she seems to run fine, although she gets significantly hotter now. The running temperature before the heater removal was about 175, now it's 195 and will climb to 210 up hills in 70-degree weather. I am concerned the summer is going to push that higher.

I think I am going to re-plumb the heaters under the bus to act as residual radiators. At that time I will likely have to replace most of my fluid, so I think I should go pay for a flush.

How much should I pay for the flush? Is it common for running temps to increase after heater removal?

[Njsurf73]

Originally Posted by Lowkee

Hi Friends,

Engine: 1998 DT466E /w that stupid half-radiator/intercooler nonsense.

So I pulled my heaters, looped the lines, and filled up the rad almost to top. Now she seems to run fine, although she gets significantly hotter now. The running temperature before the heater removal was about 175, now it's 195 and will climb to 210 up hills in 70-degree weather. I am concerned the summer is going to push that higher.

I think I am going to re-plumb the heaters under the bus to act as residual radiators. At that time I will likely have to replace most of my fluid, so I think I should go pay for a flush.

How much should I pay for the flush? Is it common for running temps to increase after heater removal?

I don't know a price, but make sure you protect the heater cores under the bus. Road debris coul leave you stranded.


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[jazty]

Have you tried closing the heater line valves under the hood and driving? Give it a go and see if you notice any difference. Typically those valves are closed during the warmer months to keep as much engine heat out of the cab as possible.

If that DOES make a difference then I suspect that looping the heater lines is the wrong thing to do. You can trace the lines to make a determination, but if the hot side of the heater line is coming straight from the block and the return line is on the cold side of the rad then looping the heater lines would make that 10%-20% of coolant flow successfully bypass the rad. I would guess that this scenario is unlikely, but it's possible.

90% of people on here recommend to loop the lines after removing a heater. This is frequently not the thing to do. If you have two heaters connected in parallel then removing one and looping the lines will make the remaining heater less effective. It all depends on how its plumbed. You'll have to trace the lines to find out what will work for your bus.

Also, who manufactured the bus body? Thomas, Bluebird, etc...?

[turf]

i've just finished changing all the hoses and flushing my motor.

its a long process.

i change a few hoses, add some radiator flush, top it off and run 30ish miles. let it cool down, drain the system. install the next few hoses, refill with cleaner and run another 30 miles. I just repeated until all the hoses were new.
i still had original coolant coming out (slightly cloudy water) after the 5th drain and fill but i called it good and refilled with 3 gallons antifreeze and about the same in water. my book says the system holds 6 gallons.

there was some scale build up visible inside some of the metal pipes that connected the hoses. the radiator cleaner never did any good in my opinion as scale was still visible at the end. i never saw debris draining from the radiator, i caught some to inspect but it seems in good enough shape to reuse. this is my first flush since owning the bus 5 plus years. it still had the same stuff that was in it when i got it.

i would have purchase one of the prestone flush kits, but the smallest coolant hose i found was a 1" id hose, and their largest adapter was 3/4" if i recall.

you probably need to bleed your heating system. air pockets will keep a system from flowing.