fkn z brake shit

[Team Rootbeer]

ok, so i have a full z32 conv. calipers, BMC, stainless lines, all the jazz. the brakes work pretty good, but i have bled and bled and bled the damn system, even with a pressure pot bleeder, and i STILL have spongy pedal, and about 2 inches of free play in the pedal before i get any sort of engagement.

another funny thing is, when im slowing down, i can depress the brakes, and they go down real far (hence said play in pedal) then i can let off, and immediatly press again and i get OK pedal, not as much play. WTF?

its been like this for a while now, and i dont have any trouble stopping at all, so its not unsafe or anything, just annoying. i want them to feel alot better.

[yfz460]

Possibly a defective master cylinder? I know I've driven some cars with bad cylinders and they feel sloppy and such with pedal feel and somtimes they stop fine, sometimes they don't.

Even if it is a new unit, not everything is perfect... I know it's a pain to redo all the bleeding (much less so with a press. bleeder!) but it's worth a shot!

[ultraDorksGarage]

is this 26mm or 30mm.

personal experience here, i have 26mm stuff, i ordered a replacement 26mm caliper and got a 30mm. 30mm caliper on a not so thick 26mm(mine have been cut once) = bad pedal.

neway if u have 26mm ones, i can go measure the two calipers if u need.(the big slot is where i measure mine from, and oddly i bought rebuilt parts, and the replacement for the 30 that was supposed to be a 26, was in between the 2, cuz half of the caliper was obviously a 30 and the other half a 26, looked so odd compared to what it was supposed to be

[Anto]

another funny thing is, when im slowing down, i can depress the brakes, and they go down real far (hence said play in pedal) then i can let off, and immediatly press again and i get OK pedal, not as much play. WTF?


It *sounds* like you have a faulty BMC. When the car is off, try depressing the brake pedal as hard as you can. If it slowly sinks down, it's shot.

[CoasTek240]

Ive heard of this problem for years. I think there is a pretty definative answer out there somewhere if you search. but not to be a dick, ill try and remember what it was. As long as your positive there is no air in the lines, theres a thread about adjusting MC. I have 30mm Z32 calipers and rotors up front with s14 Se rear assy. and stock 240sx MC and there is no spongyness whatsoever. check out this thread. its in the Archive of this forum.
http://www.zilvia.net/f/showthread.php?t=31732
hopefully this helps...
on a side note. check your PM? i was interested in the paint of your car and where you got it?

[infinitexsound]

bad MC...... or brake booster.....

[Team Rootbeer]

wow, that think is awesome.

imma try that before i completely rule out the MC or BB being shot.

thanks!

[samplesurf]

my bet is brake booster

[SoSideways]

Did you install the Z brakes correctly? Aka bleeder valves on the top of the calipers?

[sean350z]

if the booster and mc fail to solve the problem you might want to rebuild the seals and stuff in the calipers. i've heard this can help with better brake response, especially if they are old and nasty.

[harlockssx]

You can also adjust the brake booster rod, which you may have to do in your case...

[HyperTek]

Bad or leaky brake mc.. i know what you are talking about, i had that hwen i first did the first swap do to a junkyard z32 mc.. No visible signs of leak, but it was leaking at the seals inside where it meets the booster. Driving like it was normal, then all of a sudden when i apply the brakes, it would drop to thte floor. Do you see a loose in brake fluid?

i jus went to kragens(local autostore) and ordered a rebuilt one for a 91 300zx twin turbo.. Problem went away.

[MadScientist]

I have the same problem with my S14... I have wentto great extents to figure this out and replced everything with new parts.

This is what I have done:
Brakes:
OE S14 Front 5-Lug Hubs
OE R32 Front Sumitumo Calipers
OE R32 Front Drilled Rotors (295mm x 32mm)
OE Z32 1 1/16 Master Cylinder
OE Z32 Brake Booster (Painted Gold)
OE Z32 Rear 5-Lug Hubs
OE Z32 Rear Calipers (Powdercoated Gloss Black)
OE Z32 Rear Drums w/ E-brake Cables
Brembo Z32 Slotted Rear Rotors
StopTech Z32 Stainless Brake Lines
EBC Red Stuff Brake Pads
Motul 600 Racing Brake Fluid
Cusco Brake Cylinder Stopper
Speed Bleeders

Pressing the pedal while the car is off is like pushing against a brick wall... so I know the BMC and Booster are fine. I have bleed the system sooooo many times using different methods... buddy system, fully 4 spot bleed, RR,RL,FR,FL... everything.

The S14 with stock system was very responsive and the pedal presure was at the top... bairly had to press on the pedal.... been driving a Honda for the last 3 years while the S14 is being worked on... I can't stand the Honda Brakes... I deffinatly don't want my S14 feeling like that.

http://www.zilvia.net/f/attachment.php?attachmentid=2378&d=1057206267
I will be doing this over the weekend... I also think my front calipers have the bleedes on Bottom (never thought or heard of that) so I guess I'll fix that while I'm at it... cant hurt after everything that has been done so far.

Next option is taking the car to Nissan if the above doesn't work out.

Peace
Drew

[Team Rootbeer]

just finished adjusting the screw on the booster.

took it out about 2 full turns, and now it is MUCH better.

[JesusFreakDrifter]

just swap in the z32 brake pedal and master
http://importnut.net/300zxbrakeswap.htm

[prang11]

There should be an adjustable rod between the MC and the petal. Have you tried adjusting that?

[SoSideways]

There should be an adjustable rod between the MC and the petal. Have you tried adjusting that?

just finished adjusting the screw on the booster.

took it out about 2 full turns, and now it is MUCH better.

Hmm...............................

messagelengthaspaofhgaeorijqwpaohgald;kngalo;jihe

[Team Rootbeer]

lol^ pwned

massagelength

[MadScientist]

Ok so yesterday I swapped the Front Calipers so that the Bleeder was on top.... this only made since, but did not solve the problem.

I then Adjsuted the valve (plunger) whatever you want to call it... inside the Booster... First time, way to much... took about 4 tries to get the car so it would move under its own power (torque, no throtle) and DAMN is that Pedal NICE... overall I only had to adjust about 1/4 of a turn out.

No More HONDA Brakes... love it... can't believe it took this long to figure out such a simple and small issue.

Thank you
Drew

[koukimonster139]

haha spenser i had the same problem right after i did my brake swap. unfortunatly the adjustment made no difference so i bought a new master cyl. feels like sex now.

[SoSideways]

Glad everyone got their brakes to work properly.

I'll be installing mine sometime. Not sure when.

Need stock S14 rear calipers to match up with my Z32 fronts.... anyone got any? lol

[PITCH]

Glad everyone got their brakes to work properly.

I'll be installing mine sometime. Not sure when.

Need stock S14 rear calipers to match up with my Z32 fronts.... anyone got any? lol

I have some. just swaped my rears for the Z32's.

[koukimonster139]

still got my rears i think too