Improved/revised AST
 

Hey all,

Mazda made some changes to the AST in 1994-1995.
Their part number went from N3A1-15-35XA to N3A1-15-35XB and did not change until the very last FD was built in Japan.

Anyone know what the differences were? It apparently doesn't "split" and dump the coolant as the previous version did...?

Mazda probably reacted to an obvious problem... Was it really addressed? How?

Please guys, don't bring up the aftermarket aluminum or other ASTs.
Let's only discuss about the "revised" stock AST.

Thanks!

pretty sure every one either ditches the AST or goes metal.

May be you could call Ray Crowe and see if he knows the difference.

Most likely upgraded plastics. I have seen MANY Japanese FD's with stock AST's so there's something to it.

Dale

Higher quality plastics and a revised seam. Much less prone to splitting.
I've never heard of a 94+ AST breaking.

Yeah, from what I kept reading, it appeared to only be ASTs from '93 that were failing. Mazda really had no choice but to do something.

Not challenging at all but are these documented facts or that could at least be supported?

All I can add as "supporting" document is that as per the EPC, Mazda gave instructions to scrap all units of the previous revisions.

If anyone has anything (comparing pics perhaps), please post them!

My buddy has a '94 PEP that he has owned since '97 when it was 100% stock. His AST split on him in maybe '99.

I just checked it out in the EPC:

The newer AST was implemented on the 1st of march 1994.
It would be nice to know when his was built... Or even if any FD built after that has split an AST...

Here guys... Answer from Ray himself:

The seam was modified. The replacement part will not split like the original.
The replacement tank has been in my car for many years without problem.

Thanks
Ray

How much does a stock one cost? Lower price or wanting to maintain an oem look would be my only personal factors in getting one.

They will actually turn green over time, but not sure if that also affects this 'revised' one as well.

My '94's (built Nov. '93)"XA" AST broke a nipple at 98K miles... Replaced with an "XB" model; the plastic does look a little different. Hopefully this one will outlive me!

The one on my 95 split about 3 years ago...

When you say it split: Did it crack or really split open to dump the coolant?

Would you have any pics of that?

Your car is a '95 so i guess it was built after march '94. Can you confirm the date or the ASTs part number if you have it?

Unless you've got some sort of jonz for plastic, I'd just get a metal one and forget it.

It pretty much blew up...coolant everywhere. No pics or part number...

Thanks for the update!

Did you get a chance to check the manufacturing date of the car?

Unless you've got some sort of jonz for plastic, I'd just get a metal one and forget it.

This information is good for stock class auto-x guys though.

For now I am just stretching the stock class rule allowing addition (note: not removal of anything) of a coolant overflow tank in stock class rules as my car came with metal ast and no one cares in my little local events.