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HQ V8 radiator overflow bottle or not??
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The HQ always seems to blow out the top water from the radiator after a drive and then it sits for a while. It has done it for years, and when I recently changed radiator thought it might be Ok from now on. However still does it.
Would fitting an aftermarket overflow bottle and associated radiator cap fix the problem? I assume the excess water goes into the tank, and as it cools the vacuum change sucks it back into the top radiator tank?
Any tips on the best way to solve this, or just keep topping it up every few days? Sick of the greeen dribble at the servo when I pull up for gas......
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wouldn`t hurt, I had a HZ ex-cop car that had an overflow which looked factory/dealer fitted.
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if you regularly check your coolant level, just bung a 0.5 litre+ sized bottle in there to catch the overflow, then you can either top up coolant levels when required or tip it back in.
Theres no "real" need for a "proper" overflow system, they are there because people dont check fluids anymore.
My car only has enough resevoir to satisfy the racetrack rulemakers, but i have a fairly diligent pre/post drive routine with that car.
what cap are you using?
It shouldnt really spew coolant EVERY time unless youve given the car a flogging or tend to overfill the radiator.
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Without an overflow botle, the radiator fluid should sit about 1 1/2 inches below the cap when cold. As it warms up, it expands to fill the coolant system and radiator. If you fill it to the brim when cold, then it will overflow as it expands. With an overflow bottle (and return radiator cap) this excess is stored and returned into the radiator when the engine cools down again.
The return radiator cap has a seal around the top of the cap as well as the pressure seal . Without this, the radiator just sucks air back in past the cap, rather than drawing the coolant from the overflow. |
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WB had them standard and it does keep the radiator full all the time. When the coolant expands it has to go somewhere as you can not compress a liquid. They are a good idea in my opinion. Adds to the capacity of the radiator by a small amount as its always full as well.
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sounds like your block needs a flushing & a new thermostat.. |
HOLDEN The Great Way to Move |
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Kevins(monaro202) on the money. |
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Every motor blows a small amount of coolant out the overflow. If its pumping out litres then maybe there is a bigger problem. Does it just drop to the same level and stay there if you dont top it up? If so this will be no drama and a overflow bottle will keep it full.
As the coolant heats up it expands and out the overflow it goes. After that initial bit has come out it will stay at that level and not spit anymore out unless it gets pushed hard on a hot day.
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Thanks for all the advice guys.
I think the first ime it was over full, I have only toppped it half wayin the top tank to day, so will watch it.
It has clean and tested radiator, block and heater flushed and an new termostat. I'll check the pressure on the cap, I'm not sure what it is rated at.
cheers,
Scott
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HQ V8 radiator overflow bottle or not??
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