Cooling System

[schafvw]

hi
we have a M/H with a C-7 cat engine [50000 miles] the dealer said we need a coolant flush. could I just drain the radiator and refill. [ how much ]
rudi

[weredoingit]

Originally Posted by schafvw

hi
we have a M/H with a C-7 cat engine [50000 miles] the dealer said we need a coolant flush. could I just drain the radiator and refill. [ how much ]
rudi

Draining the radiator does just that, (Drains the radiator) You need to drain the engine block as well. Why does the dealer say you need a flush?

[Alan24601]

Is the coolant testing bad? If not why do it?

[Bigd9]

I drained the coolant in my coach with the C-7 Cat engine 3 1/2 years ago. I then flushed it with tap water, and added a cleaner. Ran it for a while and flushed it twice. The last flush was with distilled water.

My notes indicate I used Shell Rotella ELC. Added 4 1/2 gallons of ELC ($72.13 from NAPA) and filled the rest of the way with distilled water. According to my notes, Freightliner indicated the total capacity was 38 qts for my coach (including engine, heater and hoses. I also replaced both radiator caps ($5.00 NAPA)

I drained the system by draining the radiator using the drain petcock. 32 quarts came out, so that means 6 quarts were left in there somewhere. There is a drain bolt/plug in the engine block, but I couldn't get it to come out, and I sure didn't want it to break off! Some people have removed the bottom radiator hose to drain the system, but I didn't see any reason to do that.

NOTE: Freightliner does not recommend using ELC antifreeze. They indicated it corroded their installed sensors in the radiator. Caterpillar says its OK for their engines, but if Freightliner isn't happy, then they are not happy. Freightliner recommends a regular low silicon type of antifreeze.