Quick question…if brake discs are put on the wrong way round, so the grooves are swooping the wrong way (e.g. forwards instead of backwards) can that have an effect on the efficiency of the braking?

 

I wouldn't think so

 

Yes as the vanes are slanted for dispersing heat, also will chew through you pads in on wrong, the only ones I see that are wrong way are the ksport discs

 

As I understand it it's not the surface grooves that define disc rotation direction it's the vanes inside the disc. If these are straight then the disk can be fitted to either side, if they are curved they must be fitted to the correct side

http://www.apracing.com/productimages/discdir.gif

 

No it does not make a difference in performance if the grooves are the wrong way round , But it will dispel the dust better having them the way we recommend , at the top of the disc , the groove points at the windscreen
Cheers Ian

 

Thank you for the replies…very helpful Trying to work out why my ProDrive Alcons haven't go the braking efficiency I would expect them to have? Just noticed that the garage have fitted the discs the wring way round, so wondered if that was the problem. I'll whip them off and swap them over anyway to help dispel the dust.

My discs all seem ok, as do my pads.

The only other thing that I can see is the brake hose looks like it's bending about 60 degrees, due to looking like it's not long enough for the caliper? Could this be stopping fluid flowing freely and therefore not working the calipers with enough force?

I must admit, the pedal also feels slightly soft, I'd say it needs to be pressed maybe 2cm down before it starts to feel like the brakes are coming on?

Any ideas anyone? If I can't find the issue then it will have to go into a specialist garage to check over. Don't get me wrong, the car stops safely, but for a set of Alcons, I would expect much harsher stopping power to what I am currently getting.

 

What pads are you using ?

I'd also try bleeding if the pedal has got play.

 

Using the standard ProDrive pads with original discs.

You'd think that a garage would bleed the brakes correctly, but i only used them as they were doing the MOT...maybe big brakes are something they aren't used to and it's not been done right?

 

How old are they , are they bedded in ?

 

Your Alcons are definatley fooked best thing is whip them off and give to me I will dispose of them safely
Or you could just bleed them properly most likely your problem unless your pads are glazed over or very old

 

They are used discs and pads, but seem to have plenty of life in them? I thought at first that they may just need bedding in a bit after fitting, but they don't seem to be improving much?

Definately not the Alcons as just been completely refreshed at ^^^^^ Godspeed

Think maybe I need to try bleeding the system again, then if no good maybe a change of discs and pads? Reluctant to try the discs and pads route until I know it's definately that as I'm sure you all know, they aren't cheap! Lol

 

Could well be the disc/pads due to the age of them. Have they been sitting around for ages? We're the discs corroded before? Maybe a good clean up would help them.

 

If everything seems good , calipers will be fine it won't be discs , if can only really be pads , pads make a huge difference to a brake system , are there any markings on the back of the pads to see what they are?

 

Not meaning to change the subject here but is there any reason why you won't reply to my PMs Ian? I'm only after a couple of small items, maybe that's the problem. If it helps I spent the guts of £400 with you earlier this year for STI pads, discs, braided lines etc.

 

the original Alcon / Subaru one piece discs DO have internal curved vanes and hence need to be installed correctly on the side they were designed for - however this would only affect the cooling and not the "feel"

i would inspect the pad and rotor surface to see if they are contaminated or glazed in any way??

 

I already replied letting you know we don't have original R clips , we have some that aren't a perfect fit , if you want originals it would be a main dealer
Cheers Ian

 

Sorry Ian, no reply in my inbox hence me bringing it up again. Anyway, thanks for getting back to me and I've PM'd you back.

 

If I remember rightly, the pads did look a little 'shiny' before they were fitted.They have ProDrive on the rear of the pads. There is a lot of 'meat' on the pads, which is why I thought they would be fine...plus the shinyness I thoughtwas just from them being off of a car for a few weeks and would just be removed after a few miles with general braking.

It's beginning to sound more and more likely that the pads could be causing the issues...after reading the advice from the specialists above.

The discs seemed all ok?

 

A few high speed stops should remove any glaze

 

That's what I thought but the braking hasn't improved