Poor brakes...help and advice

[wantavr4]

Ok, My legnum has brakes that stop like a dead cat on a tile floor.
First of all they are spongy to begin with, i will only get a pedal when i reach just before half way. Been like this since i bought it, but had two scares in the last week where the pedal went to the floor so i must get this sorted.

The car is fitted with evo 8 brembos(previous owner)
Using racing blue dot 4 fluid
New pads- non branded - also used carbonetic pads that came with the car as spares to no difference.
Bleed the brakes today incase there was air in the line but made no difference.

My questions are, are the origonal vr4 brakes 2 or four pot?
Would it be possible that when they changed to brembos they never changed the master cylinder? Could that be a fault. or would the origonal be sufficient.

My mechanic took her for a test drive tonight and said it was like the brake fluid was boiling after 4 minutes in the car. when slamming on the brakes the car comes to a slow stop, not a sudden stop which you would expect.

There is plenty of fluid in the resevoir and there seems to be no leaks in the callipers or lines.

Any help greatfully apreciated.

[Ryan]

Master cylinder died perhaps? (I'm no expert I'm afraid).

VR-4 brakes are two piston calipers in the front, singles at the rear.

[Davezj]

As i under stand it the stand VR4 master cylinder does not need to be changed when doing a brembo upgrade.
it may just be a broken/warn out master cylinder it is 10 years old now. the seal may be knackered. or there might be an issue with servo assist. the vacuum pipe that goes to the servo.

when i had a master cylinder fail in my MK II escort the problem that occurred was if i held the brake on it would bite and stop the car but when i held the brake on, the pedal would gradually push to the floor, but then the brake pressure would fade away completely and if it was on a hill it would start to roll away when my foot was on the floor. i would then have to pump the pedal to get the brake pressure back.

i didn't have any fluid leaks so it must have been the fluid leaking past the master cylinders seals, unfortunately the replacement seals did not fix the problem so it was a new master cylinder for me.

these are just ideas i am not sure.

[wantavr4]

Thanks davezj and ryan,
Its like your problem with the mark 2, i was heading for a ditch and i had to pump the pedal 2 or 3 times befor i had a sufficient brake to stop the car.

Myself and the mechanic are stumped. I think i will replace the master cylinder as an atempt to fix it. Should i go for a new vr4 ms or will i go ahead and get one for an evo 8 since im changing it?

[Davezj]

I would go for a second hand master cylinder as new would be astronomical cost.

give calos-1975 a pm as he is stipping his VR4, there are other people breaking cars on here and they are all good people, but i know carl has one and it is being stipped off a good working car.
give him a PM and let him know i put you in his direction. i have had quite a lot of stuff off him in the past and it has always been good stuff.

he should be able to post to Ireland without a problem.

you can search on "breaking" and check out the for sale section of the forum.

but remember it still might not be the master cylinder it is just a theory that the seals have failed at this point.

[Nutter_John]

In my view the master cylinder needs to be changed if you are using brembos front and rear , the amount of pedal travel is obscene when using the 1" stock cylinder .

The evo's use a 1 1/16" cylinder which makes them a lot beter , but this is not a direct fit to a vr4

now if your car is a pre-facelift and has had the nitrogen recall then as part of that work Mitsi seem to replace the master cylinder with the bigger one .

[Turbo_Steve]

It's not that huge a job to chop it over to an Evo Master Cylinder is it?

I'm seriously considering this for mine.

I'm also aware that fitting bigger brakes WILL put more stress on the seals in a small master cylinder: if nothing else they will travel outside the usual wear area, and have to start coping with with a slight variences in the wall of the cylinder.

[Nutter_John]

connections are different on the evo so you need to convert

[Davezj]

mine is a Pre facelift with the recalls done. so that,s why it was recommended for me not to change the master cylider. sorry missed the fact that his is a 99 leggie which will be a facelift.

[wantavr4]

Its a face lift.

ya, i say i will go for an evo ms.
hopefully it will solve the problem.
Ys steve, i was thinking the same that the origonal would not have the ability to cope with the stress of the extra pressure needed fot the 4 pots. Hence why we think the fluid is boiling due to having to standing on the breaks to stop the car.
Cheers for the advice guys.

[wantavr4]

Sourced an evo 8 brake master cylinder for 70 euro.
well chuffed.
Hopefully geting the mechanic to replace it next week and hopefully the car will stop again.

Will let you know if the ms resolves the problem.

[Gly]

the evo 5/6 master is a direct bolt in,

the evo 7-9 needs the end fittings on the brake lines connecting to the cylinder changed to suit,

not all evo 5-9 masters are 1 1/6, some are 1"
it depends on which options it had, abs/non abs/rs etc.

ive had both and evo 8 and 6 master, evo 6 is by far the easiest to bolt on,
that said still using the standard 1" vr4 master with no issues with my brembos

[wantavr4]

connections are different on the evo so you need to convert


Like what will i need to convert?
Chop n weld or adapters or what will i need?

[wantavr4]

the evo 5/6 master is a direct bolt in,

the evo 7-9 needs the end fittings on the brake lines connecting to the cylinder changed to suit,

not all evo 5-9 masters are 1 1/6, some are 1"
it depends on which options it had, abs/non abs/rs etc.

ive had both and evo 8 and 6 master, evo 6 is by far the easiest to bolt on,
that said still using the standard 1" vr4 master with no issues with my brembos


How do i find out if it is 1" or 1 1/6? i have the new master cylinder here, what do i look for?

[Gly]

the under side of the cylinder has either 1 1/16 or 17/16 cast into the underside for the larger one,

the small one and vr4s just have 1 cast into the underside

[maydave]

Ok, My legnum has brakes that stop like a dead cat on a tile floor.
First of all they are spongy to begin with, i will only get a pedal when i reach just before half way. Been like this since i bought it, but had two scares in the last week where the pedal went to the floor so i must get this sorted.

The car is fitted with evo 8 brembos(previous owner)
Using racing blue dot 4 fluid
New pads- non branded - also used carbonetic pads that came with the car as spares to no difference.
Bleed the brakes today incase there was air in the line but made no difference.

My questions are, are the origonal vr4 brakes 2 or four pot?
Would it be possible that when they changed to brembos they never changed the master cylinder? Could that be a fault. or would the origonal be sufficient.

My mechanic took her for a test drive tonight and said it was like the brake fluid was boiling after 4 minutes in the car. when slamming on the brakes the car comes to a slow stop, not a sudden stop which you would expect.

There is plenty of fluid in the resevoir and there seems to be no leaks in the callipers or lines.

Any help greatfully apreciated.
I tried all types of front discs & pad variants recommended by VR4 specialists. None worked, all seemed to overheat, boil the fluid etc, fading juddering the lot UNTIL I ordered the cheapest stock parts from Camskill, The set of front discs & pads came to total of £109 delivered. The car now brakes & stops to perfection. Eurospec kindly fitted them, just to compliment them on their excellent service & super hostpitality.

[Turbo_Steve]

recommended by VR4 specialists.

Cool...that's what I'm hoping.

Just out of interest...er...which VR4 'specialists'?

I can only think of two, and one of those covers "performance mitsubishis", and has a fair bit of personal experience with VR4s.

[wantavr4]

I GOT BRAKES AGAIN!!!!!!!!!!!!!!!1

Car is sorted, she stops as fast as she goes!!

Result was replacing the master cylinder, the old one seems to have let air into the lines. We replaced the origonal with the larger ms from an evo 8.

Bleed the car with 2 litres per nipple with no result, left the car over night as we were getting a bit tired, did the same again the following day and shes sorted now.

Very happy. Cheers guys for the advice!!