EMMA UK

Hi All.

Just after a bit of advice please !!!

Just fitted a set of brand new 295mm vented / grooved & drilled disc's brand new unipart brake pads & a set of second hand but mint condition subaru 4pots to my 1996 uk impreza.
Bled it all off no air in the system pedal ain't sponge at all bedded the new disc's & pads in over about 80 miles. Then thought i will give it a boot & see what sort of an improvement the larger brakes made.
Only to find when braking hard from around 70mph what no brakes

Well thats to say the car started to slow down then the brake pedal slowly pushed down to the floor MASSIVE BRAKE FADE

Has anyone got any suggestions to fix this problem

Thanx in advance for any help.

dmc1980

had you been using the brakes much before you did the speed test? as in, where they well heated up? Could be the fluid being used. Someone on here will be able to tell you the dot whatever for the fluid, but it seems to be a common thing.

EMMA UK

Hi.

Topped up the system up with DOT4 fluid when i did the brake bleed & had done around 10 minutes normal driving before i hit the brakes hard..
The main thing is with the old 2pot callipers i had to really hammer the brakes before i got any brake fade this has got me properly..

funkyspider

Could you have got any water into the brake system when you refilled it, this water will heat up very quickly as the brake fluid heats and can cause fade symptoms.

Could the brakes be binding, so they are heating up all the time when you are driving normally, so exceed temperature and fade when used harder. Drive 'normally' without excessive braking for a few mins, then see how hot the disks are. I wouldnt go touching them with your fingers tho, spit on them and see if it sizzles

GC8

Strictly speaking 'brake fade' is caused by the friction linings gassing and not gripping the rotors. What you have sounds like low breaking effort. The former is caused by over-use of correctly working brakes, but the latter is caused by the kit not working properly.

Do they smell? Are your wheels hot (touch the tyre/rim first, then move down, dont touch the centre or studs...)? If so then you have may binding brakes but youd almost certainy have been aware of that.


Simon

EMMA UK

Thanx for the help so far Gents.

The callipers were fully dismantled cleaned then reassembled when i purchased them & have been dry stored in my house until i fitted them 3 days ago.

So i don't think there would be any water/condensation in them.
The disc's & pads where brand new in the boxes.

The car rolls with very little pushing effort & the brakes don't bind at all.

Anymore suggestions please.

P1James

it will be the pads you are using , a standard pad like the Unipart ones wont take much stick before they fade , put some DS2500's in and they will be totally transformed

EMMA UK

DS2500 ?????????

What make are these ?

P1James

Ferodo's , I got mine from Welcome To Godspeed Motorsport

monkeyboy840

another vote for those, just had those fitted with new discs and there excellent.

vindaloo

Make sure you've got no leaks and change all of the brake fluid... Then try the 70 mph thing again...

stockcar

if you used the brakes too lightly during the bedding-in period then pushed hard you would easily get too much heat transfer.............................

alyn

EMMA UK

hi.

very light braking at first then progressing to normal driving braking.

The thing is ive had loads of cars but have never come across "brake fade" like this before..

twistybits

your comment of
"then the brake pedal slowly pushed down to the floor "

sounds like a leak to me. Make sure the hoses are securely fastened to the calipers and look at the brakes hoses for signs of wear (cracking etc).

twistybits

oh,

and you have checked that the brake fluide resevoir is done up nice and tight?

zoney-WRX

did you clean the discs before you fitted them as most new discs come coated with a protective oil from new which needs to be cleaned off before use

micared-prodrive

yeap fit decent discs..355mm with green pads......stops me in a nat s fart.

EMMA UK

Are the 4pots normally Quite an improvement over the standard 2pots on a U.K. car ?????

Puff The Magic Wagon!

iTrader: (2)

Whereabouts are you? I would get your install checked as if its something that I rely on to save my life, ensure its done 100% properly.

Have you not warn your discs/pads in properly as in light/normal braking for 100 miles or so, or was it a case of a few gentle miles then wallop! ?? If its the latter, you may have glazed your discs?

Also, ditch the Unipart pads and get Ferrodos or even OE Subaru ones. EBC also.


4 pots are a definate improvement over 2s. If you really want brakes, get AP4s

daijones

I've had the same a couple of times, though with a different brake set up. Had it serviced last week which confirmed an intermittent poor peddle feel, despite a couple of bleeds. Looks likely to be pad knockback, probably caused by a knackered wheel bearing. Luckily I'm still under warranty so gonna get it checked out by a main dealer in a couple of weeks, and drive carefully in the meantime. Might be worth you looking into the bearings, or possibly a knackered master cylinder.

D