Spongy Brakes

So last year I put on new brake pads and rotors but didnt bleed the brakes. This made my pedal firm as hell so I got my brakes professionally bled. After that was done my brakes felt spongy sometimes and sometimes u could push them and they would go in with ease and stop great. For instance, I would drive with them spongy, go into my friends house for half an hour, come back out and drive home and then they would be awesome, not spongy anymore. Now they are just spongy all the time. Did the professionals bleed the brakes wrong? Would stainless steel brake lines cure the spongy-ness completely? Or sould i get stainless steel brake lines and caliper bushings? Any one got the cute and tips on how to fix it? Thanks for your time.
 
if they are spongy, you either have air in the lines (incorrect bleeding) or your brake lines are flexing too much. ive got the same problem, but my brakes were bled really good with this compressor thing we have at work. id just take it back to where you got them bleed and let them guy test drive it and they should fix it for free if they notice it has air in the brakes. thats just common courtesy on their part.
 
ECU5.0 said:
if they are spongy, you either have air in the lines (incorrect bleeding) or your brake lines are flexing too much. ive got the same problem, but my brakes were bled really good with this compressor thing we have at work. id just take it back to where you got them bleed and let them guy test drive it and they should fix it for free if they notice it has air in the brakes. thats just common courtesy on their part.

okay thanks. so its not just because i have the stock brake lines?