1979 Holden Commodore VB Wagon Heater Issues - Our Shed

By: Glenn Torrens

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holden commodore wagon 3 Brisk autumn mornings revealed my wagon’s heater to be less than oven-hot holden commodore wagon 3
holden commodore wagon 5 “The old garden hose in the radiator trick” holden commodore wagon 5
holden commodore wagon 11 Everything looks clean and tidy but there was hidden trouble lurking in the cooling system holden commodore wagon 11
holden commodore wagon 6 The “coolant” is supposed to be green, not orange. Yukky! holden commodore wagon 6
holden commodore wagon 10 Everything was given a good flush with a garden hose holden commodore wagon 10
holden commodore wagon 4 The heater outlets were unblocked, bush-style and now it works like a treat holden commodore wagon 4
holden commodore wagon 9 Thumbs up, GT ticks another item off the To Do list holden commodore wagon 9

Glenn Torrens converts his Commodore's cool breeze to a steady stream of warmth

Bought in summer, it wasn’t until late autumn that I realised my new-to-me 1979 VB Commodore wagon’s heater wasn’t working too well. Despite cold-climate European origins, these early Commodores weren’t known for their burning heater performance but although air wafted to the foot wells, face vents or demister ports on command, it was only luke-warm!

holden-commodore-wagon-5.jpg"The old garden hose in the radiator trick"

My first fix-it task was to check the engine’s thermostat, a common cause of a too-cool heating system. Fast-idling a car from cold while feeling the top radiator hose is an easy diagnosis: a gradual warm-up of the hose indicates a dud thermostat while a sudden rush of warmth in the hose after five to-10 minutes shows the thermostat opening correctly. But for $15 and around 20 minutes’ work, I simply replaced the thermostat.

holden-commodore-wagon-6.jpgThe "coolant" is supposed to be green, not orange. Yukky!

While doing this, I noticed the crappy condition of the cooling system’s internals: The old thermostat was rusty and there were horror-movie growths on the underside of its alloy housing. Ewww! According to the previous owner, my Commodore had sat in a shed in Qld for 16 years; the last service sticker on the windscreen was dated 2001. Usually I change all the fluids – oils, coolant and brake fluid – in any classic car but until now I’d changed only the wagon’s engine oil and filter. This evidence of corrosion inside the Commodore’s cooling system meant it was possibly full of crud.

holden-commodore-wagon-10.jpgEverything was given a good flush with a garden hose

I removed the heater delivery pipes from the engine, poked a garden hose into one and turned it on… A great wad of orange cruddy muck splurged out. I swapped the garden hose into the other heater pipe and yep, more yukky muck! There must have been a beer can’s worth of rusty ooze hidden in that heater core!

holden-commodore-wagon-4.jpgThe heater outlets were unblocked, bush-style and now it works like a treat

The heater-hose inlet and outlet barbs on the front of the engine showed signs of corrosion that would have slowed the flow of hot water, too. Here, access was tight but I simply used a stubby screwdriver and a short bolt to scratch and poke around inside the outlets to unblock them.

I got my Commodore going again with just water in the system to check the heater’s operation before installing new coolant hoses (and coolant) a few days later. With everything unblocked and flushed-out – and with fresh coolant for the first time in possibly two decades – the heater now works nicely!



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