Hi guys need a little help.

After the wife drove the truck I noticed a strange noise in the left rear wheel (there's the first problem I know). Now I had a look at the rotor through the wheel and it looked a bit more scratched than the other 3. So i've popped the wheel off and low and behold there is only an inner brake pad.. Thats right no brake pad or shim on the outer side at all. So I've got some TRW replacement pads ($95 Repco).

Now here's the problem.

The piston is 3/4 out and I can't seem to push it back by hand. I'm assuming its been like that for a while with there only being one brake pad.

Anyhow my question is do I simply bleed the break line at the nipple on the caliper to release the pressure. Push the piston and fit my shiney new pads?

I'm no mechanic more of a "give it a go and see what happens" person..

Last one how the hell does one loose an entire break pad????