If you have been following our saga on saving a Mk2, you know that we bought the car 7 years ago. It was born in Coventry, England, and stayed there for about 15 years before coming to Canada. This is a right hand drive car and still has its English license plate on the boot. When we got it, the 3.4 engine ran good and the Borg-Warner automatic just needed a fluid change and one adjustment. It needed a lot of TLC thoughchrome work, interior carpet, and most importantly, brakes. . .it didnt have any!
All of these things have been done over the last several years, including much paint work and a lot of buffing while we waited for chrome and parts. Even though it ran pretty well, I decided to have the SU carburetors rebuilt. Most of these projects are covered at www.southernwheels.com (see Archives)
When we sent the chrome out for re-plating, it was a good time to rebuild the brakes (this was about three years ago). The car had so many of its original parts, I decided to rebuild and preserve what I could, so that I could have the OEM preservation look. Friends tell me that there were a lot of these cars made, but most of them have been changed and modernized. I kept all of my original brake parts and removed and rebuilt them, and bled the system with LMA (Low Moisture Activity) brake fluid. It is stressed in the Jag manuals, Dont get moisture into the system! So now, with brakes I would move it around the shop, keeping fresh non-ethanol gas with stabilizer and a tender on the battery. It ended up in a dark corner of the garage and one day, when I got in it to start it, I pushed on the brake pedal and it went to the floor! When I checked the master cylinders reservoir, it was empty. I didnt see any brake fluid under the car or on the inside of the tire side walls. I thought maybe its the reservoir hoses or the booster. On removal of the hoses, they turned out to be hard and brittle but they nor the booster were the problem. When I got inside of the car with a drop light, I saw fluid running down the inside on the firewall insulatorright where the brake pedal attaches to the master cylinder rod. The floor was soaked with fluid. There was also a circlip that locks the master assembly together lying there. When fluid was poured in, it would come right out onto the floor. After removing the master cylinder, I could see it was a Girling. This time, I bought a new one.
The Mk 2s were built from 1959-1967 and although basically the same car, there were changes along the way, and the master cylinder was one of those changes. The early ones used Dunlops and later Mk 2s used Girling with a spacer plate. Mine had the spacer, so the new Girling was a direct bolt-on. I bench bled it and put it on the fire wall. I am rarely affected by chemicals, but the LMA fluid burns my skin. I would suggest wearing rubber gloves when using this fluid. The time that the master cylinder was off of the car was about 3 weeks. I didnt cap the lines, but it was still a surprise to me when I got everything back together, started to bleed the brakes, and they were locked up! Every caliper was locked upno fluid came out! These are OEM. Even though I wanted to see the original lettering on the calipers, by now I was over that. The new aftermarket TRWs are okay with me. I bought all eight piston assemblies that bolt onto the calipers, found some new pipes and new pads. There are several types of pads available. I chose the soft type. they dont last as long as the hard type, but they stop with less pedal pressure, and have a good feel like old-style asbestos brake shoes on a drum brake system. The emergency brake system is a separate, but attached, unit on the rear calipers and requires its own pads. The ones on the car looked almost new, so I re-used them, but when I went through the unit I did find some parts missing. Thats one thing about these old Jagsif you have the parts books, they will show you all of the parts and 95% of the time, when you call a Jag vendor, he will have, or can get, the part, no matter how small.
Putting everything back together is a pretty straightforward process. The front piston assemblies are 2 1/8and the rears are 1 1/2 There are two pistons per caliper. The caliper frames were completely disassembled and cleaned, all of the parts were cleaned with a wire wheel and new bolts and lock washers were bought. When the assemblies were put together, anti-seize was used on bolts and parts that move, without getting any on the pads or the piston rubber parts that will swell if any petroleum products get on them. I kept the bolts loose as I assembled everything and made sure the pads would slide in and out of the frames. They have a metal tab with a hole in it, so the pads can be changed on the car using a hook to pull out the pads. With the calipers off, I cleaned up the rotors with a die grinder using 80 grit sanding disks. Everything was cleaned off with brake cleaner and the caliper frames were painted. These calipers have bridge pipes to connect the front pistons to the back, and the bleeder screws are positioned on top front and the main pipe from the master cylinder is on the bottom back side. A manual and pictures work great here.
There are two different types of bleeder screws: 1-a tapered screw and 2-a screw with a cupped end that seals with a ball bearing. When the Mk 2 manuals were printed, it shows #1 in the front and #2 in the rears. Now, it is acceptable according to the vendors, to use all of one kind. I used the ball bearing type, because I think they bleed better, allowing the fluid to pass by the ball bearing when the screw is loose and the pedal down. When the brake pedal comes up, it pulls the ball bearing back down to make a tight seal.
When we rebuilt the emergency brake, we also replaced the cables. With the emergency brake handle released, all three metal stranded cables were replaced. There is one long cable from the front to the rear, with a turn buckle adjuster at the rear. Then two short cables left and right come off of the pivot where all three attach. The short ones operate the pads on the rear calipers. There is an adjustment for the pads. A large slot head screw is on the front side of the caliper to adjust the pads to the rotor. The distance from hand brake pad to rotor is 1/32and is set with a feeler gauge. Our gauge is 12long, to easily get into the rotor. When attaching the main brake fluid lines, it should be noted that the fittings are bubble flares, and there is no substitute. Bubble flares are round and look like half of a ball with a hole in it. Bubble flare kits are available online for around $65. After the slot screws have adjusted the pads, put a cotter pin in to secure the slot from moving. These screws are turned clockwise to move the pads toward the rotor.
A quick list on removing and installing front and rear calipers is as follows:
FRONTS: 1-disconnect the rubber brake hose from the bottom of calipers J metal hose
2-Break the locking wire on the mounting bolts.
3-Remove mounting bolts, taking care not to lose any shims. If shimmed, note placement.
4-Lift caliper from car.
5-To re-install, use the reverse procedure and center caliper on rotor, each side caliper-to-rotor should be 0.010
6-Put in locking wires (Lock wire spinning pliers are about $30 online.
REARS: 1-Remove cotter pin that attaches the hand brake cable to caliper.
2-Disengage the main brake fluid pipe at inner bottom of caliper.
3-Break locking wire to the two mounting bolts, remove bolts and lift complete caliper with hand brake assembly off, being careful to take inventory of any possible shims.
4- To reassemble, do the above in reverse order. Always center caliper frame with rotor 0.010 inch each side of rotor.
5- Put in new mounting bolt locking wire
6-Reconnect hand brake (always use new cotter pins) Bleed the system using LMA brake fluid. On our RHD car, we bleed L-R, R-R, L-F, R-F three times.
Now everything is working, and we are putting on the new chrome. We will tell you where to find all of these difficult-to-find mounting clips and bolts. Watch for us to get this old Jag back on the road soon. Keep em driving!