vindaloo

Hi all,

I'm not completely convinced by the brakes in my P1.
Thing is I'm running AP 4pots on approx. 300mm AP disks. (They came with the car and I haven't measured them that scientifically yet). Pads are Ferodo DS2500s.

Problem is that I can stand on the brakes until the pedal hits the bottom and the ABS only just cuts in. It doesn't feel like I'm stopping that rapidly. The pads need to warm up a little before they work properly. For ordinary driving they're fine but I don't seem to get any additional stoppage if I stamp on them.

Vindaloo.

ozzy

John Felstead uses those brakes @ the ring and I don't think he's ever said they didn't slow the car well I wouldn't think you'd find a better kit (maybe AP 6-pots) to be honest.

Have you had the brake fluid changed or even bled to check the pedal is firm enough?

How old are your discs and pads?

Stefan

vindaloo

Ozzy,

I have no idea how old the disks/pads are. The car was serviced in June/July when I bought new DS2500s but they weren't needed. Plenty left on the old ones. The disks look invulnerable! Well chunky, clean and no corrosion to see.

I haven't changed the fluid or bled the brakes, though it might be an idea to bleed them at least. I'll lever the wheels off tonight and have a look-see if there's anything awry.

I hope it's just fluid/bleeding as otherwise it could get messy. I don't think Subaru warranty AP brakes.....

Vindaloo.

DaveW

Sounds like they need bleeding. But try and find out what fluid was used last time. If it was AP600 or another racing fluid then its not compatible with normal stuff, so it may be worth replacing all the fluid in the system to make sure. In case at the last service normal fluid was used on top of racing fluid.

You may also want to check that the pads haven't glazed, a quick rub with some sand paper will sort them out.

DaveW.

ozzy

No, Subaru will not warranty those brakes. The previous owner must have put them on to replace the original 4-pots.

Check there's braided lines fitted, but I would personally get them bled and filled with new fluid.

Your brakes should be awesome.

Stefan

vindaloo

Right,

Levered one one the wheels off last night. The disks seem to be 308s. The brake pipes are braided. Think I'll get them drained, refilled. I need the rear brakes looking at anyway.

BTW: 308s look tiny on 18s.

Thanks,

Vindaloo.

Puff The Magic Wagon!

iTrader: (2)

Change the fluid whilst you're at it & fill with Dot 5.1 (if not already)

You won't get the ABS to come on unless your wheels are losing grip on the road surface due to the retarding of the brake. ABS will not come on under normal braking on a dry surface. The harder you press the pedal will not change that.

Stamping suddenly on your brakes (panic braking) is more likely to induce the ABS, but of course won't slow you any quicker when its working.

Having "big brakes" and getting the ABS to come on is not the aim of them. They are designed to stop you quicker and at a higher speed. ABS does not help you stop quickly & is not an idicator of braking efficiency.

stockcar

be wary of 'dot5.1' fluids as this is not an indication of the temp. ability/ performance.........
the 'dot' rating is generaly only an indication of how "hydroscopic" a fluid is (i.e. how quickly it absorbs moisture), a better indication is to check the max. temp. rating!!
a lot of competition fluids are 'only' dot4 (or sometimes not at all due to high moisture absorbtion) and yet will outperform 'dot5.1' due to the above!!!
feel free to mail for any advice,
alyn - asperformance.com

DaveW

Just for info, I used to use Castrol SRF racing fluid (one of the best you can get) on my MY99 running standard 4 pots with GPN disks and pagid blue pads and I never did manage to fade them properly (road use only). A good fluid is essential in my opinion.

DaveW.

vindaloo

PtMW,

Perhaps stamp was the wrong word... I tend to brake, then push down harder once I feel the car has changed attitude due to the original application. (Method born of having driven old, cr*p cars with interesting braking issues....and learning that the wheels need to be in a straight line before braking hard).

Stockcar

I know the fluid was hygroscopic and that racey stuff was worse for that, hence it's best to replace the fluid every couple o'years.


Overall, I'm more concerned that I can bottom out the brake pedal.
I'm wondering whether part of what's happening is that the scoob doesn't nosedive under braking, hence I'm thinking it's not braking. Doesn't help that my other car is an AX GT - chalk and cheese.

Vindaloo.

stockcar

if you can "bottom" the brake pedal then it sounds like there is air in the system and would advise getting this checked ASAP!!!
for all scooby's have a poor pedal sometimes, feel wise, what you describe is defo a fault.........
alyn - asperformance.com

X SOOOBY

i have these brakes on my uk00 and take my word these are awsome brakes

i do trackdays with them and they anchor you up from high speed time and time again

so good luck with getting them sorted