18/12/10 - Caliper Rebuild (part 1)

The Jimny pulls sharply to the right when braking which tends to imply that  the left hand front brake is not coming on properly.

Therefore I decided to strip an rebuild the calipers as they have hard a hard life over the last 3 years.

First I got hold of a Caliper Refurbish Kit from www.biggred.co.uk. - for my Japanese Aisin Calipered Jimny the kit was BRK205131

As you can see it contains the slider boots (therefore is a saving on the Suzuki price straight away!) along with the piston seal ring and piston boots with retaining rings. It also contains some nipple covers.

Before you start on the caliper you need to ensure that as little brake fluid as possible is lost (although they will have to be bled through anyway). I always trap some polythene across the top of the Brake Fluid Master Cylinder, the seal creates a vacuum to help stop it leaking.

Then you have to remove the caliper and remove the brake pipe. This is the Banjo connection at the back of the Caliper, I put a bolt and washers through the banjo and tighten to prevent leaking and sealed in a polythene bag.

That then leaves me with the caliper.

Push the caliper sliders out and remove the rubbers, my sliders moved ok in the end so it was not the sliders that were a problem.

The piston would not move so (and look away now if you are a perfectionist engineer!!!) so I put a slim bolt in through the Brake Pipe connection hole and tapped the piston out.

As I tapped it out the problem became obvious, a torn piston boot.

A rusty and dirty piston.

More dirt inside the whole thing.

This shows how the rubber was rotten and the retaining ring was prised out of the  edge.

And the corrosion on the piston.

I cleaned up the piston with VERY fine wet and dry, you know when you have got it all clean when you can slide the piston in and out by hand freely (but only if its exactly straight, if its off centre it sticks)

To be continued..........see PART 2