Victor
07-07-2014, 01:23 PM
Dear Group -
I recently replaced the AF in my radiator. Fearing trapped air pockets after refilling, I'm checking and bleeding from my (brass replacement) bleeder screw after drives (engine off). But today a new and bazaar leakage of coolant occurs upon trying to purge remaining air from the bleeder screw. I immediately get a puddle of AF below the radiator. It's not coming from the bleeder screw, but from the
bottom of the radiator somewhere. This occurs ONLY when cracking the bleeder screw open and as I watch tiny air bubbles escape I'm loosing AF on my driveway!
Having never experienced this before, the only thing I can think of is that my E34 (525i '95, M50TU) is actually designed to shed added AF if filled over the fill line on
the expansion tank. Mine is currently over filled by an inch or two, and coming down!
The question is this: Why would the (slightly overfilled) rad lose AF while bleeding a hot engine? Is it because its overfilled?
While I'm at it, another point I've never understood: When refilling the radiator one is supposed to fill the expansion tank entirely (not just to the fill mark) until AF begins
to flow from the (opened) bleeder screw. So where does the excess AF go? Presumably, it replaces trapped air, but in my case the level remains high. Does this mean there's
more trapped air to purge?
Many thanks!
I recently replaced the AF in my radiator. Fearing trapped air pockets after refilling, I'm checking and bleeding from my (brass replacement) bleeder screw after drives (engine off). But today a new and bazaar leakage of coolant occurs upon trying to purge remaining air from the bleeder screw. I immediately get a puddle of AF below the radiator. It's not coming from the bleeder screw, but from the
bottom of the radiator somewhere. This occurs ONLY when cracking the bleeder screw open and as I watch tiny air bubbles escape I'm loosing AF on my driveway!
Having never experienced this before, the only thing I can think of is that my E34 (525i '95, M50TU) is actually designed to shed added AF if filled over the fill line on
the expansion tank. Mine is currently over filled by an inch or two, and coming down!
The question is this: Why would the (slightly overfilled) rad lose AF while bleeding a hot engine? Is it because its overfilled?
While I'm at it, another point I've never understood: When refilling the radiator one is supposed to fill the expansion tank entirely (not just to the fill mark) until AF begins
to flow from the (opened) bleeder screw. So where does the excess AF go? Presumably, it replaces trapped air, but in my case the level remains high. Does this mean there's
more trapped air to purge?
Many thanks!