Front Brake Caliper Overhaul
had a nasty experience with my Capri a short while ago. I came off the A14 slip road at 70mph, put my foot on the brakes and the peddle went straight to the floor! With some frantic pumping I managed to get some stopping power and limp home. The passenger side caliper, wheel and tyre were too hot to touch for nearly two hours. When I eventually inspected them I discovered that one of the pistons had seized and overheated the brakes. The resulting heat had boiled the brake fluid which created vapour and made my peddle go soft.
To strip and rebuild a caliper is actually dead easy and afterwards my brakes were considerably better than before. Before you start this overhaul you will need to purchase a caliper repair kit from a motor factors. The kit comprises a pair of outer weather boots and a pair of inner seals. The pistons are NOT included in the repair kit and if it subsequently looks like they have had it you will need to get a hold of a pair. It may be quite hard to get new pistons but I believe that the Capri Club sell them.
You will also need a new set of brake pads as it is extremely foolish not to replace them during the strip down. Also make sure that you have some DOT 4 brake fluid.
With the front of your Capri jacked up and secure and the wheels removed you can proceed to remove the brake caliper from the car. There are actually two types of caliper that could be fitted to your Capri: Gurling or ATE. The Gurling calipers (like mine) are recognised by the fact there is a 'G' logo in the casting. In any case they are very similar and I believe the kits are the same; but be prepared to be asked "which type" by the spares guy!
Remove the flexible hose by carefully undoing the union with a pair of open ended spanners (varying between 11 and 15mm). Have a jam jar ready to catch the brake fluid. You will need to bleed the brakes once the job is completed.
The caliper is bolted very tightly to the bottom of the strut by two large 17mm bolts. These will also have an anti-
The brake pads are removed quickly and easily with the caliper off the car. Simply remove the retaining clips and withdraw the two retaining pegs. The pads should just pull out with a pair of pliers. Clean up all the metal surfaces with wire wool dipped in white spirit as there is a lot of baked on brake dust.
With the caliper cleaned up we need to remove the pistons. Firstly remove the outer rubber boot which is there to prevent water and dust getting inside the piston. The boot is retained by a circular clip which is included in the kit. You simply prise it off and pull the boot off. In my case all that was left was a pile of grey ash!
One way to get the pistons out is to reconnect the caliper to the hose and get someone to pump the brake peddle. The pistons should rise up out of their seats and if you are lucky they will pop out. Get ready as there is quite a bit of brake fluid behind them. This worked well for three of mine but the seized piston remained firmly stuck. To get this one out I resorted to gently tapping it with a hammer and screwdriver using the notch at the top to get a grip. After rotating the caliper around and around and tapping for about ten minutes the piston finally fell out.
At this point you need to be nice and clean so go and wash your hands! The cylinder and pistons should be nice and smooth without scores or scratches and should be rust free. One of my pistons was a little corroded at the very top but I attacked it with some diamond paste and she polished up nicely. In any case after a good clean and polish the pistons should appear like new. If you are in doubt get some new ones. Don't compromise safety when it comes to brakes!
The next job is to remove the old rubber seal that is about a quarter of the way down the cylinder. If you use a very small screwdriver you can carefully prise it out. It is simply a square section o-
The new seal from the kit can be worked into the groove. Wipe some clean brake fluid on the seal before fitting. With the seal in place it is time to refit the piston. Again, wipe some clean brake fluid over the piston surface and slot it in the cylinder. The easiest way to push it home is with a piece of wood slotted through the caliper. Press down on the wood making sure the piston is going in straight. It should slide right down to the bottom of the cylinder.
You can now fit the new weather boot over the top of the piston and secure it in place with a new clip. And that's all there is to it. You need to do both pistons of course and I strongly recommend that you overhaul both calipers together.
You can refit the new brake pads to the caliper before refitting it on the car as it's quick and easy. Remember to use copper grease on the rear of the pads. The full procedure for doing this is in the service guide. With everything bolted back on the car the brakes will need bleeding. You may need to be patient as it can take a long time to work the fluid through into the calipers. The procedure for this is also in the service guide. With the brakes bled and the brake peddle nice and hard you can go for a test drive. Test the brakes carefully and be especially careful with your braking for the first 100 miles to allow the pads to bed in.
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