I recently bled my brake lines and now the first initial push on the the brakes is super soft while any subsiquent push is hard (normal feel). It seems like the first push pressurizes the line. I'd keep on having to do this every time i'd want to stop.. any suggest on what might be causing this? thank you

 

air in the lines probably. bleed the brakes starting with the one furthest from the master cylinder then work ur way closer

 

definatly air!

 

Bleed them again to see if it gets better. Hopefully it is just air in the lines.



Another possibility is that your master cylinder went bad during the bleed. This isn't very common, but if you have some corrosion in the master cylinder, you can chew up the seal during the bleed. The piston pushes all the way to the end of the cylinder during the bleed and the seal can be ruined in the process. I killed the master cylinder on my daily driver bleeding its brakes due to this issue.



I don't want to scare anyone away from bleeding their brakes, but this can happen. The best defense is probably to bleed them often enough that you don't have old crappy fluid and you wipe the inside of the master cylinder down during the bleed. A pressure bleeder might be a safer alternative (since you don't push the pedal in the process) if you have a car with nasty fluid and that hasn't been bled in many years. In that case, though, it might be time for a new master cylinder anyway.



-Max

 

hmm how much do master cyclinders cost?

 

Reman master cylinders are roughly $100 + core at any auto parts store. If you do some work on your car, installing the master cylinder is something you can do yourself without too much trouble.



If you plan to upgrade your brakes, or simply want less travel in trade for higher effort (which is actually nice for modulation), you can install the master cylinder from a Mazda 929. http://www.rx7turboturbo.com/ has details on the 929 installation that covers making new hard lines. This may be helpful if you plan to use an RX-7 master, too, in which case you don't have to make any brake lines. I paid $140 for my reman 929 cylinder (including core), but they didn't let me return my RX-7 master.



If you are strapped for cash, I think I still have my RX-7 master cylinder around that I will sell for $20 + shipping. It has 100K miles on it, but it was still good when I took it out. Email me at max@maxcooper.com if you want it.



-Max