My ast is bent out of shape on the lip area, it is aluminum. the question is should i buy a new one or buy the m2 bypass kit? which would be better?

 

If yours still works why replace it?if its just cosmetic damage keep it.

 

its really messed up it wont hold pessure, it leak out the coolant on the side and i just bought a new cap. its bent on the top so it wont seal and i tried bending it back and it wont work.

 

If it won't seal , replace it. Some people like to eliminate it. I prefer to keep it.

 

which is better remove or to keep it

 

That depends on you. It seems to be a little more of a PITA to burp the system without one. I like the idea of having a little more coolant in the system, even if it is another point of failure.

However, people are running just fine with and without them, so it's a personal preference.

 

I have been running without mine for quite some time now. Even after multiple track events I haven't seen any temp problems.

 

I would keep it even though I deleted mine for my Single turbo upgrade. I have to burp this thing for a week after I open up the system. Get a new Can.

 

my mechanic has not had a tank for 6 years with no problems. He replaced the part on the water pump housing that has the cap on it .( did not buy any kit ) , $30 off a 2nd gen.The burping does take some time, the car uses the space for a fan on the IC unit and the tank for the 2 cycle oil for the OMP.

 

thanks for all the replies. im going to eliminate it, i just order the part off the 86 rx7 for $35 and ill see how far that takes me. how do you burp it without the ast?

 

One way is to take loose the water line to the hot wax rod and hold it up to let the air go to the highest place and fill the housing up. or fill it run alittle refill and run alittle then refill ect. ect . My mechanic does this because all the lines to the throttle body are gone with their nipples removed and pipe pluged on the motor

 

its been a year since my ast has been eliminated. i have had zero problems with my cooling system so far. you should be fine. just top off your coolant with water the next morning after you install or should i say uninstall?

 

The Air Separator Tank is supposed to be there for the air bubbles to go. I say put one back in.

 

The 787b has one. If it's good enough for Le Mans, then it's good enough for me

 

This has to be the most restrained AST vs no AST thread I have ever seen. How'd we get like this?

 

Good Point I agree with you.


-Mancho

 

Mazda went to extremes to make this car as light as possible.

drilled holes in the brake pedals
used all plasic hinges and connectors in the car
plastic entanks on radiator and IC
burrowed out the spokes in the wheels
aluminum hood
made the drivers side door manual locks

I can go on and on. You have to ask yourself why mazda put the AST in the car when they could have saved weight and money.

Then you ask why does the 787B have an AST?

I'm keeping mine.

 

We get more mello as we age...kind of like wine LOL

 

Yeah, I am sure the Mazda engineers that spend millions of $$ on R&D just thought that an AST would look cool. Sure, rip that sucker outa there! I would remove the overflow tank at the same time.

On a serious technical note, any car that has the top of the radiator below the top of the motor needs an AST to provide a place for air to escape the system. Localized hot spots due to air pockets or boiling of the coolant have long been suspected of causing o-ring failure in these engines. So I guess you have to ask yourself, is it really worth it to save a few bucks on a new AST and possibly risk your engine?

Just my $0.02.

Jeff
(Still young and pissed off!!!!!)

 

I decided to keep mine aswell. More coolant cant hurt the car now can it? And its a good point that the 787b had one, so it sure is hell good enough to have in my car alright.

But here is a question. I've been told that the stock plastic ASTs with a newer serial number is alright to keep. I was told by a pretty reliable source too. Anyone know if there is any truth to this?

 

That sounds like a load. The fact, is that Mazda shifted to an metal one. I know there is a Mazdaspeed one.