How to Access Heater Core for Coolant Change

[hugh37]

I'm planning to perform a coolant change next week on my coach. It'll be the first, as I've been using JG Lubricant Services for my coolant analyses and Tom Johnson now recommends a change. Based on the latest analysis, Tom suggests a change without flushing should be just fine. I understand that draining of the coolant should include the heater core. I'd much appreciate guidance in locating the heater core on my coach, as well as the precise procedure for the draining of it. Thanks for any help. Larry

[Dutch Star Don]

Larry, your heater core is up front in the box on the passenger side of the firewall. There is no need to drain it. Typically, you would drain your coolant, fill it with water/distilled water and run it until the engine gets warm with the HEATER ON. With the heater on, the water would circulate through the heater core and back to the engine.

Since you don't intend to flush, you simply drain all the coolant you can. There will be coolant left in the system, that's just the way it is. Fill with the new coolant and you'll be done.

Before you do the change, some of these new OAT coolants can be recharged with an additive. You need to know exactly what coolant was installed.

[hugh37]

Thanks, Don, for your response and good info. I've been using the test strips and occasionally sending samples to JG Lubricant Services. Tom Johnson recently told me that the latest analysis shows no need for flushing, few minor concerns, but no contaminants. Freightliner/Gaffney has suggested I use Fleet Charge, fully formulated with SCAs, for refill. Much the same as original, by Alliance, I believe he said. Both are pink/purple. Following your procedure, Don, I expect few, if any, "surprises". Again, thanks. Larry