I have a 97 Civic and my master cylinder went bad. Changed it, bled lines and drive it for a couple days before I lost the pedal again. Changed slave cylinder, bled lines, and again a couple days go by, lost the pedal. Disconnected the lines again, cleaned them, re installed, bled lines fixed for a couple days. Now I have to bleed the system to get to work, it holds just enough to get me home at the end of the day. I have no leaks and the reservoir doesn't lose fluid. What do I do now?

 

replace the master cylinder again. Are you getting air out of the line when you bleed it?

 

Yes I'm getting air and I can't find a leak

 

How are you bleeding?

 

i use to have a similar problem and couldn't find a leak, i change master and slave cylinder bleed it ran fine then started to loose the pedal again, later i found out it was the rubber section of the clutch line right by the tranny that was leaking, there was a small breakage on the bottom side that was slowly leaking away, not saying it could be that but you might want to check if that is the case.

 

Ended up it was the master cylinder again. Bought parts from autozone. Bad right out of the box