300zx brake upgrade problems

[HybridOne]

So i put 300zx brake calipers, rotors, and steel braded brake lines on my '96 240sx. Then i bled the brake system, and i have no pressure, so i bled it again, and no pressure....I bled the system 4 times, and checked all my connections, and they aren't leaking. I get a little bit of pressure when the car is off, but as soon as i start the engine up, there is no pressure, and the pedal hits the floor.Could it be the brake master cylinder? does it need to be bigger, or maybe it died.....

any help is appreceated.

ThanksHybridOne

i know this isn't RB engine related, but i know all of you guys better than the rest of the people in the forums.

[candela]

You shoudl still have a little bit of pressure if you bled them and fluid was coming out of each caliper.....

Are the boots torn/leaking on the calipers at all? ALl lines connected properly ot cyclinder/booster?

[Wulfgang]

Did you do all 4 brakes? If so, then you need the 300ZX master cylinder also. Your 240SX mc piston is too small, and will thus not have much braking pressure (although this does not mean your brakes will not work - did you drive the car?).

Basically, its a tradeoff between pedal pressure and pedal travel. With the small 240 piston, you get lots of travel but little pressure. With the 300ZX piston, you get just the right amount of travel and good pedal feel.

[stillmatic]

You gotta bleed from the rear left > rear right > front left > front right.

[HybridOne]

i bled them correctly and all the connections are good. I'm not leaking anything anywhere. But haven't other people run the 240sx mc with the 300zx calipers with no problems?It's weird, once the the car turns on there is no pressure. Well...there is some. When the pedal hits the floor there is some braking. I can stop the car if it's moving 5 miles an hour, but past that it's useless.

[gani]

check how you put your brakes as in the caliper for teh right side has to be on the right side and vice versa i had the same problem a while back and i realized i had swapped sides so check on it.

[HybridOne]

my bleeders are on the bottom. So maybe they need to be on the top? i never thought it would matter, but since air rises in a liquid, it would make sence.

[gani]

they shoul be on top thats your problem. change them and im sure it will be diffrent

[Wulfgang]

Should be on top. Did you do all 4?

[Joe]

my bleeders are on the bottom. So maybe they need to be on the top? i never thought it would matter, but since air rises in a liquid, it would make sence.

your calipers are backwards

bleeder = up

always. on everything.

[HybridOne]

i didn't do all 4. I'll reverse them tomorow. Then, if they work, i'll post pics of my unpainted S15 conversioned S14 doing fugure 8's. Thanks for all the help guys.

[Dano]

i didn't do all 4. I'll reverse them tomorow. Then, if they work, i'll post pics of my unpainted S15 conversioned S14 doing fugure 8's.

heh, cant wait!:D

-Dan

[HybridOne]

yea, that worked. i now have brakes.

[Wulfgang]

Also make sure that the curved part of the clips on those 300z brakes are at the bottom of the caliper and not the top. Putting the curve at the top causes the pads/rotors to wear faster.

Someone explained why once, but I can't remember why. I think the curve acts as a spring to pull upwards on the brake pads.