- Front Brake Caliper
- May 2004 was the time to look carefully at the condition of the front brake calipers. A known problem with these is that the pistons corrode, they are made from steel and chrome plated. Unlike ordinary calipers, the AP racing calipers have no piston boots to protect the pistons when they are exposed from the caliper, consequently they soon rust. My LC had 63,000miles when I bought it, I did notice some corrosion during a quick inspection, but was quite surprised at just how bad they really were. Initially I wanted to replace the discs and pads at the same time as renewing the wheel bearings. I quickly realized that because the pistons have to be pressed all the way back into the calipers, the corrosion was bound to damage the seals and more than likely result in fluid leakage. So I just changed the wheel bearings, as I had a MOT the day after, I used the old discs and pads. It passed the mot with a note about the discs being worn which was a bit of an understatement as they were 2mm below minimum thickness !!
The following is just an overview with gaps......you should be capable of filling in the gaps.......if not you should'nt be working on your car ;-) ..........that's my lazy ass getout........
With the wheel off first job was to soak the long cap head screws which hold the pad retainer casting in place, and the bleed nipples and the two 19mm hex bolts that hold the caliper to adaptor bracket. I have heard of removing the 2 cap head screws that bold the caliper to the adaptor bracket, but these can often be difficult to remove. The brake wear sensor can be carefully withdrawn at this point, providing you don' t brake it it should be looped and tied back out of the way, I did'nt need to replace this because the pads did not have the required cutout.
Above shows the shiny new wheel bearing previously fitted a few days ago, your's will be brown and slightly rusted.....as this one will be in a few months I am sure. You can also see the hose clamps to stop all the all the brake fluid being lost.
Removal of the pistons is easy, I used a adjustable pipe wrench to grip the end of the piston, twist from left to right an the piston will slide out with the aid of the spring behind.
The rust is very bad, difficult to believe that the last time the pads were replaced that the seals did not leak.