put 300zx brakes on my 240sx, can't get it to keep pressure.

[Dirtfall]

So I just rebuild the 300zx brakes i got. Put on the conversion lines and brembo blanks. Then i bled the master cylinder. Then bled the brakes pass rear, driver rear, pass front, driver front. Theres no air bubbles in the system. We bled them 2-3 times by now to make sure. When you pump on the brakes it will build good pressure. then you step leave the brake pedal alone for 30 seconds and next time i push in the brakes theres no pressure and you have to pump the brakes to get pressure again. Does anyone know is going on?

[Dattebayo]

You probably still have a little air in the system, you have to bleed and bleed and bleed it sometimes. You also may have a master cylinder going slowly bad.

Are you absolutely sure you did not cross thread anything? I would double check any connection you screwed in to make sure it is not leaking.

[KDashy]

Are you using the 300zx brake master cylinder?

[positron1]

Are your bleeder screws on the top or the bottom of the caliper?

[Dirtfall]

Are you using the 300zx brake master cylinder?

No

Are your bleeder screws on the top or the bottom of the caliper?

They are on the bottom.

I kinda think the master cyclinder might be going bad possibly. Does anyone know if a 300zx master cyclinder is a direct swap? Cause no one has any 240sx ones in town.

[Dirtfall]

Are your bleeder screws on the top or the bottom of the caliper?

Your a genius. I took the caliper off and flipped it upside down so the bleeder screw was up and sure enough a bunch of air farted out.

[austins240]

actually you flipped it right side up. bleeder is always on top, as has been covered many times on the forums. did you search at all?

at least you fixed it. enjoy your brakes.

[Clawhammer]

You'll get a mushy pedal from the 240 MC. And yes it's a direct swap. Search around next time.

[Dirtfall]

I searched doing the caliper and rotor swap. I didn't even think about changing the MC till today so i didn't research it yet. Sorry it was such a hassle for you to answer my question. The brakes are a little disappointing with the 240sx MC so I think I'm going to upgrade to 300zx MC.


Modified by Dirtfall at 6:57 PM 9/16/2007

[positron1]

I'm assuming you have the fronts or do you have the full setup front and rear?

[Dirtfall]

I just got the fronts. I drove it a bit more today. They stop much nicer then i thought last night. I'm still used to my light little Honda hatchback. But i got tired of driving around a loud metal box. I love my kouki.

[positron1]

Sweet! I can't wait to get my fronts installed too!

[94_240sx]

Sweet! I can't wait to get my fronts installed too!

I thought you already had z32 front brakes. I'm going to do mine all at once because I want to bleed only once and do the alignment after that.