Rust on new brake discs.

wraith

wraith

Replaced all four of my discs (and pads, of course) with standard spec EBC discs because the original disks were all nasty and rusty and ugly.

A week or so on (and, admittedly, about 5 washes because I can't seem to keep the damn car clean for more than half-an-hour at this time of year) and the new disks have a light coating of rust splattered all over them.

a) Is this normal?
b) Is there anything I can do to stop it?
c) If 'a' is 'yes' and 'b' is 'no' can I get rust-proof discs from anywhere (please don't say "ceramics").
 
it could be a sign that the calipers are siezing, is it just on the back? (its normally the backs that seize with them not doing much). mine always go rusty when washing it but after a short drive there always clean again. are they shiny after a drive? if so i dont think theres anything you can do about it, just were there left to the elements, although black diamond discs never look like bare metal in pictures but i have got no idea what they are made from etc.
 
Brake discs rust as they are just bare metal which is exposed to air...

After a short drive it should clear up... however there will always be bits of the disc that gets rusty as the brake pads dont touch it. I painted them with high temp paint, making sure you dont get the paint on the part of the disc where the pad touches - makes them look cleaner

if the rust does not vanish after a short drive then there is prob a problem with the caliper not working properly or seized...

sometimes going for a drive getting the brakes warm then doing a few "stomp on the brakes as hard as you can" in a safe place from a "reasonable" speed might do the trick. if not - take them off and see if the slider pins need re-greasing or the unit replacing/re-conditioning
 
I was really meaning the non-contact areas; the bell and the rim.

There is a problem with the offside-rear caliper. I got new discs and pads last week as I say but that particular pad is only 'cleaning' the top half of the contact area and my handbrake is not working as well as it should be.

I've got black wheels with lots of space between the spokes so rust on the bells is really obvious. I've got a tin of black hammerite that worked well on my calipers, may just bite the bullet and do the bells and rims with it tomorrow (that's what bank holiday Mondays are for, right?).

The garage that replaced my pads was supposed to be looking at it but as they were also replacing 4 sets of discs, pads and springs on a tight schedule so they may have missed something. Maybe I'll have a look myself now they have loosened all the siezed bolts. I've got the service manual but I've never taken my brakes apart before so am a bit cautious about faffing about with them especially as every time I touch a bolt on this car it snaps or shears. Too skint this month now to get it looked at by a pro.
 
i had the exact same problem!!

The solution as mentioned above was to paint the non-contact areas with ubar high temp paint... worked really well and looked a lot better and lasted the life of the disc which i was suprised with considering the heat range and constant heat fluctuations! other than that - there is no other way. the EBC discs that I had had a protective coating on them but after so long, rust still raises its ugly head through it!


Regarding the rear brake - thats odd as it should make full contact there should be no half on, half off - im sure thats something that cant happen... only thing i can think of is the pad is tiny and only gripping that part of the disc or there is someting seriously wrong!! only way to see whats going on is to strip the offending caliper - check slider pins, check pad for cracks or other damage, check the sliders that the pads sit on and grease as required... and refit!! To test - have both wheels in the air - apply handbrake and see if you can spin the wheels... if one side spins but the other not then chances are fubared caliper...
 
oh - if you have never dealt with brakes before - then my advise is dont start without somebody else been there who has done it before... as you know - brakes are VERY important and although they are simple - do something wrong and you could end up in a rather nasty accident...

most garages do free brake tests these days so might be worth popping along and explain your issues to them
 
That was what I was thinking and it's why I've never fiddled with them before.
There is a Kwik-Fit next to my work who will no doubt have a look at it for free.

Braking while driving is fine and there is no rubbing with the brakes off, it's just the handbrake that not quite right but OK if I'm aware of it so I may just leave it until the end of the month and get a brake overhaul come payday. Calipers are six years old so may well end up just getting a reconditioned set.

Thanks for the advice.
 
I need to change my rear discs + pads as they are almost on metal on metal there are loads of groves in the rear discs so you could called them fucked lol
 
you want somewhere where they can bung it onto a rolling road to test the brakes - like they do when they test them at MOT time
 
the heat generated in braking doesnt help it somehow makes them rust faster must be somekind of chemical reaction to the heat
 
It not a chemical reaction to the heat, it's just that heat speeds up the oxidation process. Just paint the problem areas, I did and they look loads better for it.
 
Well even though they seem OK in action I'm playing it safe with the brakes; no parking on hills, always leaving it in gear (toe-in to kerb), lots of engine braking and testing them every few miles.
I'm booked for a brake/check overhaul at the end of the month (can't afford to, can't afford not to). Front brakes are fine and the back pair on an N16 1.5 only account for, what, 10% of stopping power when breaking heavily? so I figure I'm safe enough 'till then, they certainly worked this morning when some numpty ran in front of me from behind a bus (judging by the look on his face he left the road pretty slippery for the next car, though!).

Halfway through painting the bells on the disks, I need the car every day and as I said don't want to fsck around with the brakes with no experience so doing them in-situ one wheel a night. Looks OK (and a hell of a lot better than rust). Using Hammerite direct-to-rust gloss black. It's lasted a month on my calipers so figure it will be OK on my disks - one coat is plenty if you're careful and it comes up a nice gloss black.

Pics when it's done and I've washed the manky wheels :)
 
wraith0x29a said:
Using Hammerite direct-to-rust gloss black. It's lasted a month on my calipers so figure it will be OK on my disks - one coat is plenty if you're careful and it comes up a nice gloss black.
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I used the same stuff ;) works a treat!
 
i used hammerite on mine they looked great bit ratty now tho as the rust is getig throught the paint now but i gues the heat doesnt help
 
SplanK said:
the EBC discs that I had had a protective coating on them but after so long, rust still raises its ugly head through it!
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thats an anti-rust compound put on the brakes at the factors. It is put on so the disc's donot rust in storage. You should never keep this on when building your brakes as it will lower the performance of the brakes. You should ALWAYS clean new disc's with brake parts cleaner to get this off them
 
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