chiefmg

iTrader: (5)

I did a search but didn't find an answer to my specific question. I have a set of TII calipers that I will be installing using ReSpeed's big brake kit (eventually). While I have a GS, I have a complete GSL-SE suspension setup that will be going on the car.

That's the background, here's my question. Which brake master cylinder do I need to install for the big brakes? I have one for the GSL-SE, I can get one off a TII or 'vert at my local breaker's yard if that is better (not too sure about using a master if it was designed for ABS though). Anyone have any knowledge of this? Thanks.

RX-7 Chris

iTrader: (19)

from what I understand, the gsl-se one will work fine.

trochoid

iTrader: (6)

2nd gen masters have a different mounting pattern for the bolts so they only mount to the larger 2nd gen booster units. The FC booster units will bolt to the firewall, but will not clear the clutch master. I've been looking at at early 300ZX masters/boosters as they will bolt up and fit, but the brake lines will need redone.

Re-Speed.com

iTrader: (3)

No change needed. The only time you wold need to change anything when using our BB kit is if the car came from the factory with a drum rear end.

-billy

chiefmg

iTrader: (5)

Thanks guys, that is the info I was looking for. Like I said, I will be changing my GS suspension over to GSL-SE, including the brake master so I should be okay. I just thought with the increased piston area in the calipers I might have to source a master with a bigger piston to push it all.

rotaryboy23

iTrader: (1)

hmmm... that's strange 'cause I know I've seen a 1st gen with the TII booster on it...
That mechanic was a hack, and the car was highly modded, mind you.
It was a GSL with a TII motor, and trans, TII brakes, funky suspension, etc. and I'm pretty sure all work was done in his front yard. WOnder how he did that...

mpk490p

i believe a FD booster will fit you need to use the FB and FD spacer and either block the clutch outlet or use the fd slave for the clutch as they use the same fluid bowl, not done this yet but have been told by someone who has (RHdrive car)

trochoid

iTrader: (6)

The widening needed of the firewall holes to mount the FC booster is minimal. I'll post in a week or so and let the forum know how it went.

Heath

iTrader: (11)

Any updates trochoid?

Jeezus

iTrader: (4)

Bump, turns out I know chiefmg from forever ago

docholiday

and even in this case...the only thing that needs changing is the proportioning valve right?

twinkletoes

iTrader: (17)

Billy, make a kit for 81-83 small spindles.

trochoid

iTrader: (6)

I have the FC master brake booster mounted, just not plumbed yet. Turns out the FC NA and TII brake masters have the same part number according to the FSM. Something I didn't expect with the differences between the single and 4 pot front brake calipers. Hopefully I'll have the brakes plumbed in the next couple of weeks if my back holds out. I tried fitting an 87 300 ZX booster but it's too deep to fit as it won't clear the power steering hard lines.

bwaits

iTrader: (12)

Sorry....late to respond.

No, you would also need to change the master cylinder. They are different from drum to disk. I have never investifgated how different but they are different.

-billy

mpk490p

i just done my conversion (still using the gslse booster) have bleed the brake 3 times now (left it a week after the first time to let the seals soak) but i still have loads of travel in the pedal i am using ebc yellow pads which i know can take some warming up, i have been bleeding both nipples on the rears and dont get any air but still a weak pedal, anyone else seen this?

thunkrd

iTrader: (1)

when i did mine i blew the master.. replacing the master fixed my problem

mpk490p

how do you manage to blow the master!

RotaryRevn

Hmmm, sounds like your keeping your car Twinkletoes!

RotaryRevn

Hmmm, I swapped my disc brake rear to GSLSE brakes all around........ I guess I should upgrade to the gslse master

thunkrd

iTrader: (1)

bleeding the brakes too hard...

BlackWorksInc

investifgated? Wow! Billy's so pro he has new terminology!

Sorry I couldn't resist. Billy don't hate me!

bwaits

iTrader: (12)

I have found sometimes the swap makes more apparent an already weak master cylinder. Are you positive the front lines have the correct type a seal for the TII calipers? Any leaks anywhere?


No worries, I add extra letters now and again to keep everyone on their toes.

-billy

rotarydude

iTrader: (2)

This is an extremely common problem. We see it more often on the clutch hydraulics. Thats why I always replace the clutch master and slave at the same time.

I would be willing to bet that you have a weak master cylinder.

j9fd3s

iTrader: (3)

i haven't looked at every mazda, but certainly everything 79+ has the same mounting pattern on the firewall.

so you don't need to be stuck with rx7 boosters, you could use tribute, 626, 929....

the 929/fd/rx8 can all take the 1" master too

mpk490p

i will have a look over the master tomorrow, dont seem to be leaking any fluid but it wouldn't hurt replacing it as everything else has already been done!