Should I mount a new aluminum AST so that the cap is above the filler neck cap, below it, even with it, or doesn't it matter?

thanks

 

Mine is mounted at a slight angle below the filler neck. Its attached to my PFS SMIC. The previous owner did it this way. I'm pretty sure you can mount it where ever you want and it won't matter.

 

mine is slightly below the filer neck

mike

 

Exactly same setup as mine. No problems.

 

for some reason i thought it was better for it to be above.

 

Me too. Especially as I was getting add coolant buzzer for some time after I installed my PFS IC. The cooling system just needed some good burping

 

If the system is pressurized, it doesnt matter where the location of the single unit is. At least I think so

 

thats a good point, the only proof i had that it needed to be above was while teh car is off.

 

Yes... if the car is off, and you open the AST cap while its sitting lower then the filler neck, you will loose some coolant out of the AST. This is the only downside IMO.

 

...but how often do you just open the AST cap. If you positioned the AST above the filler neck then wouldn't it overflow at the fillerneck cap when removed which is the place most people check their coolant.

 

No... it wont overflow at the filler neck if AST is higher, as there is no pressure and the AST has another hose going back into the radiator. Coolant would go there, but it cannot push all the coolant already in the radiator out of the filler neck so.... nothing happens in this scenario