Removing/replacing 2005 Mitsubishi Colt brake discs

[dukla]

OK, so the original discs are pretty worn and have passed 2 service observations they need replacing (& micrometer measurement confirms they are dodgy) so I have some replacements (& pads) ready to go.

Except, how do you get the original discs off? There are no obvious mechanical 'locks' - it appears they are seated over the wheel-nut bolts and around the bearing by 'snug fit' only. Unlike the replacements, there are no threaded holes to 'screw' them out.

Seems I just need to try force something (like a coal chisel) in the back between the disc and some suitable hard place? Or is there a magic trick to release 75000 miles of corrosion between the disc and the bearing/backing mount?

[BTW this is the same chassis as a Smart ForFour, which takes the same discs, so any hints from experience with a Smart are relevant.]

[Canada Phil]

Hi dukla,
            Usually the disc are seated over the studs (bolt) without mechanical fastening. Depending on the Caliper design you will probably need to remove it to get the old disc off. Do not leave it hanging from the rubber hose, use wire or string to support the weight. Tapping with a hammer around the outer edge of the disc should loosen it up. I would not chisel it. Crack the bleed screw to make it easier to push the piston/s back into the caliper. If slider type calipers make sure they are sliding freely, a good cleaning and anti-seize compound is usually all that is required. NO petroleum based product anywhere near the brake system. Aerosol brake cleaner to remove all the crud that has built up. I bleed the brakes first , to clear out the old fluid, and again after replacing the pads. Use lots of fresh fluid of the correct rating DOT3? check lid of master cylinder for info.( 250+ml per wheel)  Oh and you wondered why the garage wanted so much money to do it for you 
I know i do go on a bit
Phil

[dukla]

Cheers for the help & tips - have set aside plenty of time over the weekend to take it on.

Didn't bother asking the garage for a quote: an analysis of the last (in-warranty) service indicates they charged £98.83 for the oil change (filter, gasket, flush, oil, disposal of oil, disposal of filter) plus whatever portion of the labour it took. So yeah, to do something non-trivial I can imagine an extremely creative charge!

[chop456]

If you plan on any additional tinkering in the future, a shop manual is worth it's weight in gold.  I wouldn't touch any of the more complicated systems on my car without one.

Then again, I'm fairly stupid - your mileage may vary. 

[Lorry]

And remember, if brute force doesn't work, its because you're not using enough.

A bit of proper penetrating oil on the studs may help too, and I doubt that they're as stuck as tight as you think.  I changed the discs on a 406 a few years ago, and after removing a tiny retaining screw, they just pulled off.  I wonder if expansion due to heat stops them sticking to the hub.

And if the master cylinder if full, don't push the pads back, or the fluid will spill all over the bulkhead and take the paint off.  Phil's tip is a good one

[dukla]

If you plan on any additional tinkering in the future, a shop manual is worth it's weight in gold.

Agree with the intent and have a couple on my shelf for previous vehicles, but can't find one for the (Mk 6) Colt.

[Barry]

Sounds like you need the help of Dr. Cliff.

Below is his extensive tool kit.

Essential toolkit includes:

Claw Hammer
4-in-1 Screwdriver
A straight fork (not one of your own)
Aggressive Pliers
Filet knife (never-needs-sharpening type)
Swiss Army Knife (a Hong Kong knockoff is OK)

For handy hints about repairing find him at:


http://cardhouse.com/drcliff/garage/tech/techsupport.htm

[dukla]

Sorted - it was easier than I anticipated. Some gentle bashing around the outside and then a firm whack from the back and off they came.

Glad I did it - both discs were slimmer than spec.

Thanks again for hints/tips.