z32 brakes question

[mutkung]

What's up?? I finish installing the z32 brake conversion last week. it's a 1990 NA 26mm. I also install a brake 300zx brake master cyliner. The pedal feels really good when the engine is off, but when the engine is on the pedal become quite soft. No leaks or anything. I still use the original brake pads that came with the caliper. Here are the details of what i install: 1990 300zx NA 26mm. calipers, 300zx SS brakeline, 1990 300zx turbo master cylinder, brembo rotors, motul dot4 brake fluid. I don't know if that's how the pedal suppose to be like or what. Any body that have done the conversion already how does the pedal suppose to feel???? does the MC have to do any thing with it?? thanks

[ALTRNTV]

did you bleed the system? cuz if not, then that's why your pedal seems soft

[mutkung]

I did bleed all 4 of them.

[nlzmo400r]

did u bleed hte mastercylinder before installation? also, how did u get the '5' sided plug out of hte 3oozx mastercylinder?

[drift into a curb]

you need to bench bleed the master cylinder. It'll take out most of the air of the MC. After that when you have it on the car, bleed each of lines when attached. Then go around the car. Most likely there is still air in your system.

[SoCalS14]

How do you 'bench bleed' a MC...I have one I about to install along with the rear brakes...

[drift into a curb]

Put in on a bench vise and fill fluid to the top in the MC. You'll want to recirculate the fluid back in to the reservoir with hoses/adapters that screw into the MC (should have it at your auto parts store). Then pump the piston with an old screwdriver (Push in about 1/2" to 3/4" slowly at first, then you can increase pump speed). It'll help get the air out of the MC before you start. Make sure to keep the MC full with fluid. After you install it, bleed the 3 main lines that go in to the MC until the air is completely out. Careful, brake fluid is corrosive to paint.

[drift into a curb]

http://www.theclassiccougarnetwork.com/tccn/encata/tech/v746/stimg13.jpg

[mutkung]

i c i c. i didn't bleed the master cylinder before i put it in. That may be the reason.
thanks

[mutkung]

did u bleed hte mastercylinder before installation? also, how did u get the '5' sided plug out of hte 3oozx mastercylinder?

http://importnut.net/300zxbrakeswap.htm#MC

using an undersized 6-sided allen tool

[nlzmo400r]

didnt work, its just rounding

[thx247]

drill it out, use an Ez out. That was the only way that worked for me.

[orion::S14]

Also make sure the bleeder screw are ON TOP of the caliper...many people install the calipers upside down in their haste to get their new brakes on...then you cannot bleed them properly.

FYI...

- Brian

[s13koupe]

I have the same problem with z32 brake but 30mm. No matter how I bleed it, it still soft like a mofo so call up a few friends and this is how you suppose to bleed it.

Ofcourse you will need 2 people.

1-Pump peddal 3x and hold it.
2-release fluid from caliper nipple and tight it.
3-pump peddal 3x and hold it.
4-release fluid from the caliper nipple and leave it open, do not tight it
5-Pump peddal 3x while the nipple is open and hold it.(you will see a stream of fluid comming out)
6-Now tight the nipple.

repeat step 3 to 6 for 2-3 times, and then do step 1-2 as your last thing. I know these steps are kinda weird but its very effective and your peddle will feel like a rock.

[mutkung]

i bleed the whole thing again it feels a little better, but I'll try to bleed it again later maybe it'll work properly. thanks

[Zoom8112]

I have the same problem with z32 brake but 30mm. No matter how I bleed it, it still soft like a mofo so call up a few friends and this is how you suppose to bleed it.

Ofcourse you will need 2 people.

1-Pump peddal 3x and hold it.
2-release fluid from caliper nipple and tight it.
3-pump peddal 3x and hold it.
4-release fluid from the caliper nipple and leave it open, do not tight it
5-Pump peddal 3x while the nipple is open and hold it.(you will see a stream of fluid comming out)
6-Now tight the nipple.

repeat step 3 to 6 for 2-3 times, and then do step 1-2 as your last thing. I know these steps are kinda weird but its very effective and your peddle will feel like a rock.

did this work for you? how were the results?