Brand New Mintex Discs Immediately 'Rusty'

3953 Views 14 Replies 8 Participants Last post by redfox666, Jun 2, 2012

ck_uk

Discussion Starter · May 30, 2012

I recently fitted new front Mintex discs, but was appalled to discover that after only one journey in the wet the central 'hub' area of the discs was entirely covered in a rusty colour. I can't believe it's a Mintex-only problem but anyone else experienced this? Is there a trick I've missed while fitting? Like smear the things in waterproof vaseline (not that I'd want to put anything like that near a braking surface). I'll have to get the wheels off again to inspect/clean, but reluctant to do that if they are just going to look rusty again soon. It just looks really cr4p.

On a side topic, one reason for replacing my old discs was that braking was uneven i.e. i think the old discs were warped as you could feel it in the brake pedal as the car slowed to a halt. I thought the new discs would sort that but it seems the problem is still there altho to a lesser extent. Could it be the alloys?

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b1mcp

· #2 · May 30, 2012

I wouldn't put grease/vasoline on there - it will only attract dirt and allow it to stick. Clean them up and use High Temperature paint.

Warped discs will cause a pulsing sensation when slowing. If it's the front discs I'd expect to also get the pulse feel through the steering. Remember that Rear discs can also warp and your problem could be there.

You can check for warp by clamping something (screwdriver) close to the outside face of the disc, rotating the disc and observe the gap between disc and your clamped pointer. Ideally you would do this with a dial gauge to measure the run-out but I appreciate it's not a tool in everyone's kit.

Big cat little cat

· #3 · May 30, 2012

I found the same thing with new Mintex discs. I've not had chance to sort it yet, but I'm hoping that a wire brushing and a wipe round with an oily rag will do the trick.

Looks crap at the minute though.

ck_uk

Discussion Starter · #4 · May 31, 2012

I found this link which talks about zinc primer to resolve. OK if that's what it takes but the whole issue is daft if you ask me - why don't the manufacturers 'seal' this area of the disc or coat with non-rusting material on the hub area.

This must mean that every other jag owner on this forum who has ever replaced their brake discs must have had the same problem? And either sprayed the effers up prior to fitting as per this link, or just lived with it (which I can't believe).

rusty brake disc, how to stop it.

BuckMR2

· #5 · May 31, 2012

Great info, was just about to fit my front Mintex discs but will now use zinc primer first

speed8

· #6 · May 31, 2012

The high temp exhaust spray paint seems to do the trick also. I've just done it with new discs on the Lotus and despite rain and a heavy track day they look fine.

If the surfaces of your new discs are bare metal they will get surface rust.

wiadereczko

· #7 · May 31, 2012

had this same problem with the mintex disc. Painting is look good but just wonder is not affect loosing the temperature bu disc ( if you now what I mean)

redfox666

· #8 · Jun 1, 2012

EBC discs don't have this problem

Big cat little cat

· #9 · Jun 1, 2012

I'm going to paint mine brown so you can't tell they're rusty!

wulfrun

· #10 · Jun 1, 2012

When the discs look rusty coloured, just go round the block when the weather is dry and they will be all shiny and new looking when you get back. Not much point painting them though, as heavy braking will rip the paint off PDQ along with the smell of red hot paint ?
Its not likely to improve the efficiency of the brakes either.
Wulfrun

BuckMR2

· #11 · Jun 1, 2012 (Edited)

It's the hub area that's getting painted NOT the braking surface!!!Think I will use high temp engine paint or caliper paint.Once caliper paint has heated and cooled a few times there will be no smell and it should allow the heat to disappate

wulfrun

· #12 · Jun 1, 2012

rusty disc's

BuckMR2 said:
It's the hub area that's getting painted NOT the braking surface!!!Think I will use high temp engine paint or caliper paint.Once caliper paint has heated and cooled a few times there will be no smell and it should allow the heat to disappate

Sorry!
I can't see the center of the hub as its covered by the middle of the alloys with the cat motif in the dead center.
The only part of the disc I can see is the bit that is the braking surface, which does go rusty in wet weather.
Wulfrun

ck_uk

Discussion Starter · #13 · Jun 2, 2012

@wulfrun

I'm only talking about the central hub area - not the disc surface and not the area behind where the wheel attaches, as that obviously can't be seen.

Very grateful for all the responses on this as it seems to be a common problem (although not with EBC discs then, wish I'd bought those now). Also, the very outer edge of the discs seems to suffer as well - i.e. any area of the disc unit which is not the braking surface and is exposed. Now I understand why, given time and left untreated, the rust in these areas can set in and make the disc look exceptionally unsightly, even though the braking surface is still tickety-boo.

BuckMR2

· #14 · Jun 2, 2012

@wolfrun
There are may sizes and styles of wheels and discs,so you will see some and not others.You may be lucky as far as seeing rust is concerned with not seeing rust due to the size disc/alloy wheel you have on yours.
On my car with huge 20" alloys and 5 narrow spokes you can see the vented edges of the discs and the outer part of the hub area of the HUGE 326mm discs, so defintely a contender for painting.

@ck_uk
I wouldnt worry about not using EBC discs
I have used both and the Mintex are far cheaper and as effective.
The EBC (all grooved versions) get rust in the grooves as its not in contact with the pads

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redfox666

· #15 · Jun 2, 2012

It took well over a year before I saw any rust on my previous grooved discs.

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