Sorry for dominating the forum gang, but my rig needs help. The brakes have about two good pumps in them before the reservoir goes bone dry. I'm not leaking fluid form the wheel cylinders or at the master cylinder. I can't locate any leaks underneath the chassis. Is it my master cylinder? Where it the fluid going?

Thanks.

 

If a good inspection of the entire system is not revealing any external leaks then it could be possible that master cylilnder is leaking into the booster itself. Have never run accross that on a Mazda however in 17 years of working on them so I would be double checking for external leaks. Caliper piston boots can hold a lot of fluid before starting to leak. Try carefully lifting the boot from around the piston and see if fliud comes out.