ever since i swaped my b16 into my 89 crx hf, my brakes are acting weird. i used crx dx hubs and knuckles and calipers. i had my brakes bled and after a while of driving, my brake pedal becomes soft sometimes. it seems to go back and forth being soft and firm. when it's soft i can push it to the floor. does my vacume lines running to the map sensor affect this anyhow? could it me my master cylinder? it was fine before. my large line running from the brake booster to the im seems alright. i'm not leaking brake fluid anywhere. it might just be me but it seems to be affected after i turn my steering wheel, but it might just be coincidence. can anyone help me??

 

Does the pedal seem to get less firm on hot days ? It sounds like you might need a new master cylinder or a new brake booster.

 

yes it does seem to get soft on hot days. how can i tell if it's the brake booster or the master cylinder.

 

Before you change any of those, I would bleed the brakes again. Change all the old brake fluid out and put brand new stuff in. Also bench bleed the system. Also, do your brake pedal get soft when you press down on it, or is it just mushy all the time ? If the bleeding the brakes don't work do this, if you hold the pedal down and it sinks to the flow while the car is off its the master cylinder.

 

i ended up swapping out the m/c and bench bleeding and bleeding out the system. so far so good. i'll let you know if the problem comes back. thanks for the info.