brake master cylinder/booster size [Archive]

Gly

17-02-2007, 04:31 AM

ok, as a few of you know,
ive changed to brembos...

car originally started with the single pot caliper and 254mm disks,

can anyone confirm that the v6 brake cylinder and/or booster is smaller or the same size as the VR4 one?

ive bleed my brakes a couple of times now,
pretty sure theres no air in the lines,

basically when i need to break i really have to give it half a pedal first and then one the second push the brakes work real well!

just not on the first,

im thinking i may have to get either a booster and cyinder from a vr4 or evo?

but will rebleed them again just in case,

just getting tyred of taking the wheels on and off.

Subaru ETA

17-02-2007, 04:52 AM

from what i remeber i dont think there is any difference.... no leaks or anything?? vaccum hose to booster ok? no kinks in any lines? i have you manually bled them or you using a air sucker? know they are stupid questions but you know anything is poss!

Gly

17-02-2007, 05:21 AM

no leaks that i can find,
no kinks i can find,

i manually bleed them using a one man bleeding kit, (one way valve on a hose)

basically when the cars not runing,
i can pump the breaks a couple of times and its rock hard,

once the cars started it becomes soft and squishy,
and lacks feeling

bradc

17-02-2007, 05:24 AM

To me that problem sounds like a problem with the lines or something like that, I can't imagine that fitting bigger calipers would cause that sort of problem.

Gly

17-02-2007, 05:29 AM

theres 8 more pistons to move then there originally was,
they are somewhat smaller now thou.

maybe now the cylinder cant push enough fluid?

will bleed it again later,
no motivation left at the mo,

****en hot outside!

Subaru ETA

17-02-2007, 05:32 AM

what i find sometimes helps is to crack all the nipples and just let it slowly gravity bleed for awhile

bradc

17-02-2007, 05:36 AM

We could always have a look and compare the sizes tomorrow

Gly

17-02-2007, 06:56 AM

well, i just bleed the whole lot again,

had the whole car up in the air on stands....

there was no air, went thru another 500ml botle of fluid,
and it still seems to have the same issue?!

will have a look at some other cars tomorrow i think.
see if theres any diff in the cylinder/booster sizes

bernmc

17-02-2007, 07:43 AM

I've got an EVO master cylinder in the garage - measured it once but can't remember the sizes! I'll check for you this w/end when I finish work. I don;t think it looks any bigger than the VR4 item.

Gly

17-02-2007, 07:50 AM

ok cool thanks,

now just to find out if the v6 item is smaller than the vr4 item,

ive looked up some part numbers in caps

54107A for the booster assembly
54010A for the cyliner assembly

can any one comfirm if these are the same as the vr4 (prefacelift??) items

Gly

17-02-2007, 09:10 AM

ok the parts on a vr4 have the same numbers.

so there goes that thorey!

so i either have a massive air bubble in the lines,
or my master cylinder is on the way out?

will depressing the brake to the floor when bleeding damage it?

bradc

17-02-2007, 09:55 AM

does Kenneth still have his one from his 2002 VR-4?

Gly

17-02-2007, 10:05 AM

yep he doz,
will see how the day goes tomorrow.
have another go at bleeding them,

or might just take it to the workshop thats done my servicing
on my car befor and let them have a go.

bernmc

17-02-2007, 04:02 PM

I think Marcus (rally205) might have had a similar problem.. or SGHOM? can't remember. Solved by a pressure bleed...

Might be worth searching the brembo threads.

Gly

17-02-2007, 07:21 PM

what pressure bleeding?

is it something i should get a workshop to do for me?

bernmc

17-02-2007, 08:39 PM

what pressure bleeding?

is it something i should get a workshop to do for me?

yes. some DIY kits available for it too. NOt sure of the exact methods workshops use, but essentially brake fluid gets pummped through the system under pressure rather than you pumping the brake pedal.

Gly

17-02-2007, 08:59 PM

ah yep.

seen a kit on trademe, but wasnt cheap $200...

ill take it to the workshop during the week,

AncientOfMu

19-02-2007, 01:44 PM

ah yep.

seen a kit on trademe, but wasnt cheap $200...

ill take it to the workshop during the week,

did the pressure bleeding fix the problem? I seem to have a similar issue at the moment...

Gly

19-02-2007, 07:11 PM

having it bleed at a workshop tomorrow,

got tired and lost motivation in the weekend,

been searching the MLR, one found one guy that has the exact same problem as me...
he never said he resolved it or how! :(

but from other posts ive read it sounds like air in the line or abs system.

the workshop is going to vaccum bleed the system for me tomorrow moring so will know if its fixed it then

Gly

21-02-2007, 07:41 AM

well,
today my pocket is $100nz lighter,

and there isnt much (if any improvement) in the sponginess,
they think the master cyilinder may not be big enough.

also ive been doing some more fiddling with it...

will disks that are to thin make a diff??
the fronts are just on there limits,
and the rears are a 2-3mm thinner than minimum!

bernmc

21-02-2007, 09:07 AM

I wouldn't think that thin discs would afect the pedal feel - once the pads are up against the disc it should take the same amount of pressure to brake.

Do you know anyone with a brembo'd VR4 that you can compare with? I have a bit more pedal travel than before, but it's not spongy, and stops like @$!£!!

I'll try to remember to measure the EVO cylinder this evening when I get home. You can compare it with the one you have on (but you'll have to take it off to measure the piston... another bleed after that etc).

Just by eyeballing the thing, it didn't look any different from the Leggy's.

Anyone here with a leggie cylinder lying about that they copuld measure and compare with my EVO measurements?

Gly

21-02-2007, 09:28 AM

yeh its strange...

when the motors not running, i can pump the pedal and it becomes rock hard,

but once the motors started it becomes all spongie

Gly

22-02-2007, 05:04 AM

been doing some reseach

and the evo 5-6 master cylinder is 17/16"
----- (17/16) inch = 26.9875 millimeter

and the vr4 item is 1"
----- 1 inch = 25.4 millimeter

so the bore on the evo item is bigger,
and can push more fluid,

thats a differance of
1.5875mm,

im not sure what the stroke is on the car so can work out how much extra the evo item displaces,

but this may be the issue on my car?! is it significant enough?!

any more input is greatly appreciated

so now im gonna find me a evo5/6 master cylinder!

Kenneth

22-02-2007, 05:56 AM

it is the stroke that is important.

The smaller bore means you actually get more pressure multiplication on the pistons, but if the stroke is shorter then you may have issues such as you have encountered. if on the other hand the stroke is longer, then you just need more pedal movement, but get more force on the disks for the pressure you put on the pedal

you really need to find out what the stroke is.

Gly

22-02-2007, 06:27 AM

bradc

22-02-2007, 06:54 AM

Remember as well that the area difference isn't 26.9875/25.4 = 1.0625 ratio, it is 26.9875^2/25.4^2 = 1.1289, which is a sizable difference.

I still think there must be something wrong though, Uc's car isn't like that at all, you and me have both driven it, and the brake pedal doesn't feel like what you're describing.

Kenneth

22-02-2007, 06:58 AM

yeh but the stroke shouldnt change if im only changing cylinders,
and the pedal determines what the stoke can/will be.

it will only move as far as it can now,

but because it has a bigger bore and therefore more fluid withinn,
with the same stroke it will move more fluid,
thru the same lines, giving more pressure to the calipers

correct?

it depends on what the standard stroke is on the EVO... what if it has less travel than the Legnum?

The point I am trying to make is that it may not matter, get the bleading done and then see if that helps.

Is the facelift VR-4 master cylinder different than yours? If so, then it might be worth while changing, if not then you shouldn't need too.

Have you looked at the pedals to see if there is any stoppers or anything?

Gly

22-02-2007, 07:01 AM

yeh, looked into that,

all the legnum/galant v6/vr4 cylinders are the 1" size

Gly

22-02-2007, 08:18 AM

think ive got it now!

my booster/master combo is wrong!,

the brembos are fitted on a v6 leggy,
booster size 7" + 8" with 1" master cylinder,

the vr4s have
booster size 8" + 9" with 1" master cylinder

the evo 5/6 has
booster size 7" + 8" with 17/16" master cylinder

and the 7/9
booster size 8" + 9" with 17/16" master cylinder

so i have to get swap booster or master or both,
cant have all the small items on there!

i hope!

bradc

22-02-2007, 10:13 AM

Yeah you've got the small option for both booster and master cylinder.

Do you think changing to a larger master cylinder would affect the performance of a VR-4 equipped with brembo's?

Gly

22-02-2007, 10:17 AM

well the evo 7 has brembos aswell,

changing to a larger master, will just mean less predal travel is needed,

im gonna grabs kens spare booster on saturday and see how it goes,
ill take the master aswell, just in case mine is fubar'd

ill just change the booster to start, see how that goes,
if thats no improvement then ill swap to kens master cylinder aswell,

so i can at least eliminate parts,

bernmc

22-02-2007, 10:29 AM

Gly

22-02-2007, 10:39 AM

done. :D

Gly

23-02-2007, 04:43 AM

just called a couple of places,

manukau mitsubishi,

new genuine evo5/6 master brake cylinder,
$528 + GST ex japan,

kempys,
2nd hand genuine evo 5/6 master brake cylinder,
$120 + GST, availible now

bradc

23-02-2007, 06:40 AM

I guess we know which way you'll be going if you can't get Kenneths one working ;)

Are you keen to come out to my place this weekend to do it? Andrew (allbeitmine) is coming out to swipe some stuff from my spare engine, we could have another BBQ and etc.

Gly

23-02-2007, 07:09 AM

sorry doing it tomorrow at my dads place,
dont wanna get stuck out in karaka just incase it all turns to ****!

i maybe able to come out saturday avo, but that depends on how the booster swap goes,

gonna try just doing the booster first,
if thats dont solve it, will try kens master cylinder,

after that evo cylinder,

hopefully just the booster will do the trick!

will still get the evo master, just later on down the track.

Gly

23-02-2007, 08:21 AM

the story/problems never ends,

anyone got a facelift vr4 chassis # i could use,

have been looking at more brake related parts,
and the brake proportioning valve has a diff part number aswell!

the v6 one is MB699555

and the vr4 one is MB699554

and the evo one is MB699554

Gly

23-02-2007, 08:34 AM

bradc

23-02-2007, 09:37 AM

ec5w-0200998 ;) You really need to write my chassis number down somewhere ;)

If you do come out it would be appreciated, I'm going to be in Newmarket tomorrow morning until about 11am, so I can come and help you out at your dads place if you need any help

Gly

23-02-2007, 10:09 AM

oh is yours a late 98 facelift?
thats what caps reports it as be manufactured.. 3/11/98

whats the chassis number on your prefacelift???

bradc

23-02-2007, 11:04 AM

yeah, probably the 998th facelift made.

My prefacelift is something like ec5w-00175xx, I'll check it in the morning if you still need to know. What is your car's?

Gly

23-02-2007, 11:35 AM

mines
ec5w - 0004380,
built in 01-09-96

but reg'd as a 98? must have sat in the yard for a while,

yeh still need to know,
wanna check if the proportion valve is a v6/vr4 diff and not a pre/post diff

bradc

23-02-2007, 11:44 AM

Thats a strange one, maybe the guys in NZ registering it stuffed it up? I'll get the number for you in the morning unless someone else provides you with one

bernmc

23-02-2007, 02:39 PM

what would be more like to cause a soft pedal... (needs to be pumped twice to make the brakes solid?) (when the car is running)

wrong proportioning valve, (the evo 5/6 and vr4 one are the same, mines different but i dont know how different)

too small a brake booster, (i have same as the evo 5/6 one)

or too small a master cylinder, (i have the same as a vr4, but smaller than the evo one)

The booster is just there to assist you in pushing the pedal, so I don't think it's that. It should simply give you more/less assist, depending on size and internals.

Your problem is either with the volume of fluid being shifted with each press, in which case it is most likely to be the master cylinder, or a compressible subsance (ie air) in the brake lines.

I would have thought the proprtioning valve is only going to adjust your front/rear brake balance.

I'm not an expert (just very important :D)

Quad Al

23-02-2007, 05:59 PM

Gly,
Had problems with brakes on my late (2001) vr4 also. You can get a mitsui' service kit for your master cylinder. They are prone to weeping out of the back of the cylinder, hence losing pedal. Have you got standard flexi hoses? are they due for changing? try some stainless steel replacement flexi lines. These will most def' reduce pedal travel. Also suggest Dot5 synthetic brake fluid. Mitsui' did not mind at all when I upgraded my brakes whilst under their warranty! :inquisiti . Brakes are definately the weak link on VR4s.
There is also a factory recall on certain Vr4s were they change almost everything under the bonnet! todo with the brake system.
Are your caliper seals and all connections in good order?
Good luck.
Al.

bradc

23-02-2007, 07:11 PM

The problem where they replace everything is only on asc equipped cars, which Gly doesn't have.

Gly

23-02-2007, 09:07 PM

we need a cert to change to SS braided lines,
so still using stock lines,

using dot 5 fluid,

its been bleed 5 times now,

the pedal pumps up hard when the engines not running,
and goes soft and spongy when as soon as the motors started,

bernmc

23-02-2007, 09:37 PM

the pedal pumps up hard when the engines not running,
and goes soft and spongy when as soon as the motors started,

Normal for the pedal to 'ease off' once vacuum assist kicks in, but shouldn't become spongy.

Gly

24-02-2007, 05:00 AM

well today was fun..
liberated the parts from kens wreak,
easy as as all the bolts had already been undone,

back home, rip out my old booster,
fit the vr4 booster which is much bigger than the v6 one,

up the road for a test spin, little improvement, not what i wanted thou.
then rip out my old master cylinder, confirm it was a 1" unit, same as the vr4,

then fit the master i got from the wreak (1" unit aswell)
full rebleed again, used 1l of fluid,

went for a test spin, yeah i little improvment, still not happy....

then on the way home, the breaks felt better after having let the car sit for a while,

there is still alot (imho) of pedal travel needed, but thats to be expected,
it does bite, but im still not happy with it.

to much travel needed IMO,
so will be tracking down a 17/16 master cylinder to fit next weekend hopefully.

so once its done, ill have a evo 7 brake setup,
17/16 master with a 8"/9" booster and brembos all round.

ill update once its all changed.

bradc

24-02-2007, 07:15 AM

Well it sounds like you're getting there, it may help some others who need have brembo's, I might be keen for a 17/16" master cylinder too :)

Gly

24-02-2007, 07:23 AM

cool, ill let you know,

sent a email of to www.racebrakes.co.nz

see what they can offer.

psbarham

24-02-2007, 08:48 AM

Gly

24-02-2007, 09:04 AM

also been doing more research...

the GTOs that had 4 pots also use a 17/16 master cylinder
i my have more luck getting one of those cheap!

its a Z16A chassis

bernmc

24-02-2007, 10:12 AM

and for anyone in the uk whos interested
http://cgi.ebay.co.uk/Mitsubishi-Lancer-Evo-7-8-9-Brake-Master-Cylinder_W0QQitemZ230051921097QQihZ013QQcategoryZ1 0400QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

not to bad a price /Hmmm

I got mine along with all the power steering piping and some other bits from MLR for 50 quid delivered.

I'll wait and see how Gly gets on - may then fit the EVO master cylinder.

Gly

24-02-2007, 10:51 PM

tracked down a GTO 17/16 master,
so maybe getting it,

only diff is the fluid level sensor in the cup,
and the actual plug....

who thinks this could work?

GTO item

uploaded/1576/1172353804.jpg

VR4 item

uploaded/1576/1172353849.jpg

?

Gly

25-02-2007, 03:08 AM

ok the GTO on is a NO GO,
the cup sits on the oppisite side to ours,
and i dont think theres enough room for it,

leaving only the evo 5/6 item,
which also has a different plug for the fluid level sensor,

EVO 5/6 item

uploaded/1576/1172369244.jpg

and anyone got a pic of the evo 7/8/9 item?
specifically of the the fluid level sensor plug,
my copy of caps dont have a break down of the parts

peter.nilsson83

11-06-2008, 04:21 PM

Sorry for bumping such an old thread, but I thought I might as well continue on this one.

Anyone know if a Evo 7/8/9 Brake master cylinder works on the VR-4?
Broken mine, and have a hard time sourcing a Evo 5/6 part here in Sweden.
Evo 6 items should be avaliable via Mitsu, but I don't feel like throwing that much money their way. :)
Found a E9 master cylinder at breakers, just need to know if it fits!

Thanks!

peter.nilsson83

12-06-2008, 09:57 AM

Just ordered the Evo9 item. Should pop up sometime next week, and I'll make sure to report back if it fits properly.

EDIT:
Anyone got any idea as how to get the bloody brake lines of the master cylinder? They've settled in quite nice there, and the open-end spanner slips... Could use some heat, but don't want to ruin the cylinder in case the new part doesn't fit, and I'll have to order a repair kit.

Gly

12-06-2008, 10:36 AM

you need open ended ring spanners,

there like a ring spanner except thicker, and only open on one flat edge 5/6 edges are grabbed by it.

Davezj

12-06-2008, 01:20 PM

yes they would do it.

You can also buy hardened standard open end spanners that will not bend. they will snap if you wack it with a hammer but not bend.

The only other option is heat treat the spanner you have. i think if you Heat the end of the spanner red hot with blow tourth and quench it in water a few times this will make it hard but brittle. so it shouldn't flex on the flats of the braek pipe nuts. only thing is it might break.

But don't take my word for it they people on here that do metal stuff for a living, ask them a question about it.

peter.nilsson83

18-06-2008, 08:23 PM

The Evo9 one fits. Front pipe needs some mild persuasion, but some bending and cursing will fix that.
The sensor fits straight on. No modding needed there.
Got a buggered end on the front pipe, so it's leaking like a sieve. But I will get the proper equipment to get that sorted, and it should be up and running by the weekend.

bradc

18-06-2008, 11:03 PM

Cool, thats good to hear.

ianb

19-06-2008, 01:08 AM

Bleeding the brakes is critical, best done with a pressure bleeder such a Gunson EZbleed from Halfords, uses the pressure from a spare wheel, engine is supposed to be running (as ABS is fitted), and bleed the valves on the ABS unit, in the right order, as well as the wheels and delay valve, usually alternating wheel/delay valve (if fitted) for each wheel. Setup depends on model .

Gly

23-06-2008, 10:32 AM

you get it sorted?

any pics of the fitted item?

any improvements in braking?

peter.nilsson83

23-06-2008, 04:32 PM

you get it sorted?

any pics of the fitted item?

any improvements in braking?

No, never got around to it this weekend. :( So many things to do, so little time...
Will try to go over to my dads tomorrow and finish up. I'll try to remember to get some pics too! :)

Gly

24-06-2008, 06:11 AM

peter.nilsson83

25-06-2008, 01:45 PM

heres the evo 7-9 unit,

uploaded/1576/1214284078.jpg

and real life pic of the evo 7-9 unit,

uploaded/1576/1214284236.jpg

(i just bought this one)

i see the clutch fuild is held in the same container,
do they share the same fluid or do they have seperated area's and filling point??

.

Fluid is shared between clutch and brake.
I just led a hose out and plugged it with a M8 screw and a hose clamp.

Bought some copper tubing today to replace the damn iron pipe that goes to the front of the master cylinder... bloody pain to bend iron right!

Oh, and you might need to redo the end of the pipes going to the master cyl. too. On the vr4 there's some sort of upwards cone in the bottom of the holes on the master cyl.
On the evo one there aren't any cones. It was explained to me that you can make two kinds of ends on a brake pipe. One cone-style and another sort of funnel-style.
Don't know if I'm making myself understood. But when you take a look at it you'll hopefully understand. :)
Might be that that was causing the leak I was having, and it never got around to leaking at the back pipe since all preassure was lost at the front pipe...
Well, I'll try replacing the pipe first...

peter.nilsson83

28-06-2008, 08:50 PM

Problem with the leak wasn't caused by the ends of the pipe... The holes on the evo cyl. aren't threaded all the way down, and cause of that I wasn't able to get it tight enough... Gonna buy some new piping on Monday, and see if I can find some nuts that aren't threaded all the way down. Otherwise I'll have to modify the kind i have.

Oh, and I noticed that the fluid cup is rubbing against the sway bar, so I'll give that a beating too.

Getting tired of these brake-problems now... :(

Gly

28-06-2008, 11:13 PM

wow what a bitch!!

will the evo 7, master cylinder internals fit inside the original vr4 one?

or will the vr4 fuild cup fit on the evo cylinder?

might make it slightly easier?

peter.nilsson83

29-06-2008, 05:59 PM

wow what a bitch!!

will the evo 7, master cylinder internals fit inside the original vr4 one?

or will the vr4 fuild cup fit on the evo cylinder?

might make it slightly easier?

Hehe, yup... Things has started to look a little bit tougher than it first appeared... :) But all will be sorted, no worries.
Getting the pipes sorted should be no match, once I get the proper ends, and taking a hammer to the strut bar is piece of cake... It's not the bar running across the engine, but the piece that sits on top of the... strut?
Hehe, don't know the english word... :P The red piece at the end. :)
Just a small edge needing to be hammered in 1-2mm.

Fluid cup could fit I guess. Haven't looked at it that hard... I can take some measurements for you if you'd like. Internals wouldn't fit would they? Being different size and all?

Gly

08-07-2008, 06:06 AM

sorted yet?

peter.nilsson83

17-08-2008, 04:11 PM

OK, long time no see now...
Finally got the car running today...
Turns out it's not that difficult to bleed the damn thing once you put the calipers in their right place.. (The whole left-left right-right thing..)
Quite a bit of air gets caught in the calipers when the bleed valves are pointing down to the ground.
Feel so god damn stupid right now, but atleast it's running! :D
Definitely more pressure needs to be applied to the pedal now, but I like it!