AO Platinum Member
Join Date: Feb 2002
Location: The land that Time forgot
You need some spanners (13/14mm, 17mm) and a big hammer.
First of all you have to loosen the nuts holding the caliper body to the mounting frame. There may have sliding pins with rubber bellows mounted between the calipers and the frame.. but you'll be able to work it out quite easily which bolts to undo. When you did that, take the lower bolt out and rotate the caliper upwards until the pads clear the disc and fall out. Stick new pads in there and tighten everything up... and that's it.
In reality, when the old pads come out, it's the perfect time to clean up in there. get some wheel cleaner or brake cleaner spray and get rid of all the crud in there. Don't use de-greaser as it attacks the rubber bellows.
Remove the other bolt and take both sliding pins out. Clean off all the dried grease, rust and dirt - use emery cloth too.. and clear out the **** in the sliding pin holes. Grease up the pins with copper grease and make sure they slide smoooothly in and out before you refit them.
Before you put new pads in the caliper, use a file on the ends of the backing plates where they fit in the caliper slots. File the pad backing plate a bit so that it's a precise fit in the caliper slot. Not tooo tight but not too loose either. Use a teeny dab of copper grease on there and on the back of the pads to stop them sticking or seizing.
Wind back the piston a bit as the pads will be too fat to fit over the disc. Take the top off the master cylinder and gentle push on the piston to force it back into the calliper. Use a screwdriver across the face of the piston to give you some leverage, use a piston rewinding tool or just a G-clamp. As you push the piston back the brake fluid level in the master cylinder will rise, so make sure it's not too full. Stick a paper towel in there to soak up some fluid if you have too... but don't let it disintegrate and fall into the master cylinder. Don't get brake fluid on paint.
Fit the new pads in the caliper and bolt it to the top sliding pin with one bolt. Rotate the caliper over the disk and then fit the second bolt. Tighten everything up and you're done.
IMPORTANT BIT: Press the brake pedal a few times to get the pads into contact with the disc. Ideally I'd bleed the brakes at this point as fluid is often neglected.. you fitted new pads, so also fit new fluid. That also ensures your pads and discs are in contact and ready to go.
Discs are easy to change. With the wheel and caliper off, you just belt the disc with a hammer from behind and eventually it comes off.
If your brakes have two little flat-head bolts holding them to the hub (12mm) obviously remove those. They come out easy or snap off altogether.. They only hold the disc in place on the hub to make fitting the wheels easier so don't worry if yours are already snapped off.
The disc always seizes to the hub so you just have to get a block of wood, hold in to the back of the disk and belt it with the hammer. Rotate the disc round 90 degrees and repeat. Use some WD40 bwteen the hub nut turret and also inside the wheel nut holes. Before you fit new discs, remove any WD40 residue with brake cleaner.
If you have the little 12mm flat-head bolts they make the new discs stay in place while you fit the caliper and wheel. If you don't, the new disks won't be stuck to the hub any more and will flop about. Ask a friend to help hold them in place until you fitted the caliper. Rotate the disc so the holes line up with the wheel nut holes... then refit the wheel.
No bullets for Chaingun..