Hi all, I have an annoying problem with my 94 classic wagon, the problem is when i really push it (full boost right through the gears) Then when i need to slow down quickly the brake pedal goes solid and i have a job to stop the ******! The brakes work fine under normal conditions it's just when i've been giving it some. Any help would be greatly received, cheers

 

Do you still have the OEM sliding caliper 2-pots. If so, there's your answer! They're TERRIBLE at stopping from speed. They cause the car come to a gradual halt, rather than stop briskly!

Upgrade to the OEM 4-pots/295mm disc set up (if on a budget). Significantly better, but still lack ultimate stopping power.

Otherwise see Apex's GB on the K-Sport kit (you'd need a minimum of 17" alloys for the smallest 330mm kit though...)

 

I believe it does still have the original set up, how much are the oem 4 pots and discs? cheers Rich.

 

Check on here or eBay. They're much cheaper these days... just concentrate on a set of used calipers... but... get a set of new 295mm discs. Loads of options (depending on budget) available....

Get plain, grooved, dimpled, or grooved/dimpled discs. Don't get x-drilled ones as most have the holes put in AFTER the casting process and can cause radiating stress fractures if too much heat is put into the disc from violent heavy braking etc....

 

the problem is when running at boost for long periods there is no vacuum in the inlet manifold so the servo won't work. Its like braking with no engine running, a couple of pumps & you're out of vac. My wagon has the same problem, only thing is not sure how to cure it.

 

^^^ Interesting point too.

 

cheers joz!!

 

does the newage have a better vacuum system then to the old classic ? i know it has more braking with brembos and bigger discs but it must have better way of utiliseing it ? or is it the same after a full boost run.i had to stop today from 90 mph quite quick and it was a bit hairy(even with brembos and ds2500)brown trouser moment.

 

It's an awful sickening feeling isn't it!

 

That's exactly what happened to me yesterday but i was doing over a ton and like you say "brown trouser moment" aint the word! Trouble is if its the vacuum system i cant see what the solution could be even with bigger better brakes, bit of a design fault if you ask me, why design a car with such speed and then forget how to stop it lol.

 

You've hit the nail on the head!

It's the whole braking system that's not that great (maybe a too small servo?).

Bigger brakes etc, although much better obviously, only serve to mask the inherent crapness of the system.

 

i don't know why other people haven't experienced the problem, it doesn't matter how big the servo is if there is no vacuum there's no brakes. turbo diesel vehicles have vac pumps to get round the problem, or the other soloution would be a servoless system! who knows

 

I wonder if there is a way of fitting a vacuum pump to the impreza engine? Would be well worth fitting if it was possible.

 

alot of them are driven of the back of the alternater but they require an oil feed & return, but it could be done!