New to forum. Need help with Brake Master Cylinder long

[JP Roberts]

I recently bought a MAPCO Brake Master Cylinder reference number 1740, bore 25.4, Audi OE part number: 4D0-611-021.

I have a 1998 B5 Audi A4 1.8T Quattro and recently replaced the stock A4 rear brake calipers with the S4 rear brake calipers. Everything was OK, except for pedal travel. As the S4 calipers pistons are bigger, I also do need a bigger Brake Master Cylinder, and this is why I ordered the MAPCO BMC 1740 for the S4.

The problem is that the MAPCO BMC 1740 links to the brake fluid reservoir are in a totally different position than they were in my stock BMC (8E0-611-021) as can be seen in the picture attached, where the red arrows with a cross face an "impossible" reservoir.

Link to picture:

http://pictureposter.audiworld.com/4..._vs_s4_bmc.jpg

I need a 25.4 bore BMC that fits my car in the same fashion as my (smaller)stock 23.81 bore one in the picture does. Which Audi BMC part number do I have to order? Or alternatively, is there any special Brake Fluid Reservoir that would fit the Mapco 1740, and if so, what Audi part number is it?

'98 A4 1.8TQ, AEB engine, Oettinger chip.

[Mike@PureMS]

Sounds like you need the matching brake fluid reservoir.
I believe 4D0611301F has the ports on the side which sounds like you'd need.

[JP Roberts]

Thank you for confirming that you are positive on the side ports, Mike. Your thoughts are always welcome.

Take good care.