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Why pedal travel before any biting/braking ?

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Old 24 November 2009, 11:14 AM
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The Rig
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Default Why pedal travel before any biting/braking ?

Have just fitted as new 4 pots (refurbed ones from biggred, new seals/stainless steel pistons etc etc,look lurvly) and new discs all round, these,also seem very good so far for the price,

DIMPLED BRAKE DISCS FRNT RR IMPREZA UK TURBO 295mm on eBay (end time 07-Dec-09 21:46:59 GMT)

with standard calipers at the rear,sliding ones.

now,they are still bedding in so braking power isnt what it will be i know,but i have not far from half travel on the brake pedal before any braking can be felt/slowing down,now i have beld the system with 500ml of dot 5.1 fluid and its still like it, might retry a bleed but any other ideas ?

not pots seem to be stuck in/travelling back into caliper,pads are tight in the calipers also

cheers
Old 24 November 2009, 11:38 AM
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When you fitted the calipers , did you make sure the bleed nipples are at the top of the caliper not the bottom ?
Old 24 November 2009, 12:53 PM
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yup,bleed nipples at the top of the caliper when fitted

i can see the pads are not bedded in yet,as its been raining the disc is rusty now and only the top/bottom of the disc has wear,the pad isnt bedded into the middle part of the disc yet but i would still thought the pedal would bite at the top as the pads are still touchin the disc

tis a weird one
Old 24 November 2009, 01:06 PM
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the pads will wear to fit the discs perfectly as they are bedding in , when this is done the pedal should be firm , give them a few miles and see how they are then
Old 24 November 2009, 01:14 PM
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hopefully,they are redstuff pads and been told they are hard wearing so it may take a while,but hopefully soon !!!
Old 25 November 2009, 11:01 PM
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just a thought,but im rebuidling my suzuki gsxr as well and have used the banjo bolts from that on the scoob,they are the same pitch etc, 10X1.00 and 22mm in length,that wouldnt cause it would it,the internal fluid hole will still be the same size, a 10X1.00 banjo bolt is just that,wether it fits a motorbike or car ?????

hmmm
Old 25 November 2009, 11:09 PM
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Did you change from shonky early twin piston fronts?
Old 25 November 2009, 11:17 PM
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Originally Posted by The Rig
just a thought,but im rebuidling my suzuki gsxr as well and have used the banjo bolts from that on the scoob,they are the same pitch etc, 10X1.00 and 22mm in length,that wouldnt cause it would it,the internal fluid hole will still be the same size, a 10X1.00 banjo bolt is just that,wether it fits a motorbike or car ?????

hmmm
No that wouldn't be the problem at all , a banjo bolts a banjo bolt !

Cheers Ian
Old 25 November 2009, 11:32 PM
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The Rig
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Originally Posted by Ian Godney
No that wouldn't be the problem at all , a banjo bolts a banjo bolt !

Cheers Ian
sound,thought so and not the dot 5.1 fluid ??,non synthetic,would of used dot 4 but they had none so got this

cheers
Old 26 November 2009, 09:11 AM
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there is a slight difference in the cylinder size so have always found a slight increase in pedal travel when changing 2 to 4pot
Old 26 November 2009, 07:21 PM
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Originally Posted by stockcar
there is a slight difference in the cylinder size so have always found a slight increase in pedal travel when changing 2 to 4pot

Big difference really, 1" to 1" 1/16"

A great Improvement in pedal.
Old 26 November 2009, 07:25 PM
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cheers guys,yes,car had 2 pots a few yrs ago but have only just fitted refurbed 4 pots so the pots are very easy to move now,maybe thats why i am noticing the pedal travel with these 4 pots ?

so,id be best getting a master cylinder from an impreza that had 4 pots from the factory ?

but isnt that newer shapes to the classic so wouldnt it be different,fitment wise ??
Old 26 November 2009, 07:33 PM
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STI 7/8 bolt straight on.
Old 26 November 2009, 07:38 PM
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cheers,mine doesnt have abs so i dont think the newer m/c that aid 4 pots will work as i think the brake line holes are in different positions on the m/c, side entry on non abs,top entry on abs

i have an M/C from a 2000 sport i used to have,dont know if its just the yr that had better m/c`s or the model, ie turbo or sport ??

correct if im wrong, hopefully !!!

cheers
Old 26 November 2009, 07:45 PM
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I have a 95wrx non abs. An sti7/8 bolted straight on.
Old 26 November 2009, 07:56 PM
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sound,thats what i like to hear !!

cheers
Old 26 November 2009, 08:00 PM
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Got mine for 20 quid from a breaker.
Old 26 November 2009, 08:02 PM
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cool,will have to have a dig around, is it just the yr, so if i ask for a m/c from an impreza 2003-2005 or does it have to be from an STI 7 or can it be a wrx 2003 etc ???

will have to see if i can find a part no. for it and compare it to the m/c i have from the 2000 model i used to have/broke
Old 26 November 2009, 11:09 PM
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well,after having a dig around,using the part catalogues and the one supplied on this forum to install i get the same part number for the master cylinder for cars 1993 - 2006

part no 26401,go figure ????

g10 is for the classic, g11 is for the 01 -06 cars on this software and all of them use this part no 26401 suggesting theres no differnce ???????
Old 26 November 2009, 11:09 PM
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or looksy at the online one, the same part for all models

Brake system, Subaru IMPREZA ? Subaru parts catalog
Old 26 November 2009, 11:17 PM
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from hat i can gather,these gatalgues are a bit baffling, the casting is the same but the internals are different ?? but it still suggests from 98 - 2006

Last edited by The Rig; 26 November 2009 at 11:19 PM.
Old 27 November 2009, 08:30 AM
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I wouldn't panic. The earlier reply you got about the pads and discs getting used to each other may be the best one. I have a 1998 JDM Version 4 STI, and I have been trying to eliminate slop in my braking since I bought the car. [I had a 2002 WRX from new in the US before.] I put braided lines and a master cylinder stopper device on the US car, and used Axxis Ultimate pads, and the 2 pots on the US car worked better than the 4 pots on my current car. Current car has braided lines, I bled the system really hard, I fitted a master cylinder stopper (which is not as effective as the one for the LHD car), and have just fitted Axxis Ultimate pads. I am still breaking them in, but I observe slop in the pedal the same as you, and my car had 4 pots from the factory. I think it may be the pads getting used to the discs, or the pistons being bigger as mentioned, which works against pedal feel, or the fact that the master cylinder moves when you push the pedal. This last thing is extremely annoying, and the cylinder stopper I bought is aluminium and flexes itself, so not that good. If you can find a good mc stopper that will help (once you decide you've got the right mc).
I bet your brakes are great for stopping the car, it is just annoying that the first part of the brake pedal action is wasted.
Old 27 November 2009, 05:19 PM
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cheers for the insight, the last 2 sentences are spot on !
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