I have an 87' with AAS (doesn't work) that needs a brake master. I have one off of a 89 neither have ABS. Can I use what I have or will the AAS connection casue some issues if not connected?

 

I believe their all the same. The Brake Master Cylinder does not feed the Auto Adjustable Suspension, those are electrically controlled.

You can also swap an 87-91 Mazda 929 brake master cylinder on.

 

I am doing the 929 swap on my vert. The 86-88 with AAS has a sensor in the MC. The S5 does not have one.

 

Wow, so does all S4 or S4/S5 Master Cylinders have the lead for the AAS sensor ?

This is about as obscure as the "mileage rollover=higher performance fuel map" switch/connector behind the gauge cluster that sends a 12volt high 1.5 volt low signal to the ECU. Heard a rare store a miata wouldn't pass emissions because that switch/electronics didn't supply the 12volts needed to engague the high performance fuel map on the miata after 10K miles or so. Suposively the miatas won't pass emissions intially due to the richer fuel mixture during breakin. Wonder if the RX-8s & 2nd/3rd gen rx-7s are the same way?

 

I'm thinking only s4's where aas was offered