I'm riding a 98 S4 spec1.
had some brake binding problem so I took apart my calipers/pistons for servicing. I took apart the master cyilnder/brake pump as well to service the piston and the 2 seals.
my difficulty started when I assembled back the master cylinder and start to prime the system.
with only the master cylinder installed (brake lines disconnected from M/C), I pumped the lever few times, but no fluid came out of the M/C outlet port. I realised that the brake fluid level in the reservoir is also not decreasing. Initially I thought maybe the seals are worn and there's leakage, but somehow it doesnt make sense that almost no fluid is being pushed from the piston to the outlet port.
I tried a slightly different method to prime. I pumped and hold the lever. After this, I'd seal the outlet port with my finger and then release the brake lever. After few successive pumps, fluid starts to flow from the outlet port. I know this method is merely to force the fluid to be sucked down from the M/C compensating port during the release stroke. But the greater problem is, there's no way I could have the brake system primed with the lines disconnected. Neither is it feasible to prime the M/C first and then do a ultra quick connection of the brake lines. I think you guys know what I'm talking about.
My experience with priming a brake system is I could just install the M/C, brake lines, calipers and just loosen the bleed screw (at the caliper side), and start pumping the M/C away while maintaining the fluid level in the reservoir. I'm perplexed by what's happening to my brake system now. I even changed the M/C piston and seals. I asked an experience mechanic friend over the phone and he suspected that the M/C cylinder bore has enlarged beyong the seals' tolerance. I'm not too convinced by that actually. I could be wrong.
Anyone has similar experience? Care to point out my ignorance of the honda brake system?
Sorry that my post is a bit windy. Needed to provide the necessary info (or what I deemed necessary) to have the best picture painted.
Thank you all