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thanks to everyone who replied, i took your advice and it worked now i am back on the road and finally getting to use my new 17's to go with the r32 brakes. the problem was that i had the callipers on the wrong side i.e. the nipple was at the bottom and like u guys said it would look like its bleeding good but there was still some air trapped at the top of the calliper. so lastnight i switched them and bled the lines again and she works good. there is some soft feeling and like u said its because i am using the stock master cylinder, so the hunt is on for the r32 master cylinder and booster.

thanks again for all the help

Can we summ this all up and sticky ? )) The lines, the brakes etc ?

i'll add some into that parts list sticky when i get around to it...

EDIT: BTW while on the topic of master's and boosters, i called up holford motors here in melbourne, they quoted 150 for both a booster and master off a R32 gtst. That sounds reasonable for 2nd hand yeah? Still haven't upgraded mine since i put the r32 calipers on over a year ago...

Edited by skypy12
i didnt upgrade my booster, simply the master - its a direct fit :P

How much difference did it make when you upgraded just the master cylinder, is it worth just doing that because i have noticed that the booster on the R32's is physically larger.

Oh and ill have to send jinman a PM, around $120 is very cheap for two ADR approved lines.

so summing up wen upgrading brakes on a a31.... u need 2 change the brake master cylinder? for sum weird reason.....

not true.... stock can be used... his was just bad...

i use the stock (s13 same) the only difference is about 2inches of extra travel. actually puts it at the right heighth to heel-toe, or clutch kick in a brake-drift. but for SOLID pedal feel upgrade the MC....

Edited by 4DoorWhore
not true.... stock can be used... his was just bad...

i use the stock (s13 same) the only difference is about 2inches of extra travel. actually puts it at the right heighth to heel-toe, or clutch kick in a brake-drift. but for SOLID pedal feel upgrade the MC....

Well actually you are wrong there. Well technically if you are sooo broke and cant afford an upgrade then yeah you can use the standard master cylinder.

But really the whole point of doing a brake upgrade is to get better braking. The calipers will only be as good as the master cylinder, and if the master cylinder isnt displacing the proper amount of fluid you get shitty brakes. Upgrading gives you that SOLID pedal feel, which is what brakes are meant to feel like.

Well actually you are wrong there. Well technically if you are sooo broke and cant afford an upgrade then yeah you can use the standard master cylinder.

But really the whole point of doing a brake upgrade is to get better braking. The calipers will only be as good as the master cylinder, and if the master cylinder isnt displacing the proper amount of fluid you get shitty brakes. Upgrading gives you that SOLID pedal feel, which is what brakes are meant to feel like.

yes partly true, but by upgrading to the Z32 Master cylinder your only increasing the flow rate due to the larger diameter of the cylinder its self. the compensation for this in the S13 Master which has a lower flow rate is the time of flow through the cylinder is increased. there for a longer time till the brakes are activated fully, longer pedal travel also. but due to the fact that the GTR brakes have the same diameter brake lines and just require more pedal travel, when bled properly the S13 MC will lock the brakes just the same with a slight delay that is... now if you want to get serious and you want equal pressure you need a brake proportioning valve...

yes partly true, but by upgrading to the Z32 Master cylinder your only increasing the flow rate due to the larger diameter of the cylinder its self. the compensation for this in the S13 Master which has a lower flow rate is the time of flow through the cylinder is increased. there for a longer time till the brakes are activated fully, longer pedal travel also. but due to the fact that the GTR brakes have the same diameter brake lines and just require more pedal travel, when bled properly the S13 MC will lock the brakes just the same with a slight delay that is... now if you want to get serious and you want equal pressure you need a brake proportioning valve...

Its true, Im not referring to any particular master cylinder im saying generally. Brakes are measured in force not flow rate because its a closed circuit. Im just saying as an example.... When you see those fancy brembos like 6 or 8 pot now arent they? I can guarantee you will not see a piss weak master cylinder. The fact of the matter is that a bigger piston at the master cylinder will increase the force at the caliper pistons. Because you are displacing the fluid via a larger area of the piston face, which is more pressure. If you are using a small piston face to put pressure onto the same calipers not as much force will be on the caliper pistons resulting in shitty braking performance.

Anyway. Id say most vehicles with front and rear discs would have proportioning valves. Then again so would the newer vehicles with drum rear i think. A proportioning valve is to disperse the force of pressure between the fronts and rears, and generally its split 60/40 i beleive, 60 going to the front and 40 to the rear. Its not meant for equal pressure all round.

Just my 2 cents :)

gtrchick i think what you are saying makes sense, here is what i would do, i currently have on the stock master cylinder with the 4 piston brakes, i would look for the bigger master cylinder and put it on and see if it make any difference in performance or if it just reduces the peddle travel before the brake are 100% activated. I would try to do this mod soon and let you guys and girls know, i cant say when as i have to look for a master cylinder thats in good condition, give me a 2 week to try and source one.

  • 5 weeks later...
gtrchick i think what you are saying makes sense, here is what i would do, i currently have on the stock master cylinder with the 4 piston brakes, i would look for the bigger master cylinder and put it on and see if it make any difference in performance or if it just reduces the peddle travel before the brake are 100% activated. I would try to do this mod soon and let you guys and girls know, i cant say when as i have to look for a master cylinder thats in good condition, give me a 2 week to try and source one.

read up.... i just told you there is a difference in pedal travel... and as GTRchick says it takes more force (my mistake) though people with bad braking habits may benefit from this a little since its somewhat forgiving.

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