I admit it, I wasn’t looking forward to the job, but I’ve finally tackled the rear calipers on my 2000TC. Because the car had been sitting since 1976, I thought they were probably due for a rebuild. They were.
The thing that’s tough about these calipers is getting to them, since they’re mounted directly to the differential. Here, I’ve already removed the passenger-side caliper, after disconnecting the handbrake linkage and the brake line between the two calipers. It had been suggested to me that I could get the calipers off without unbolting the half-axles and rotors, but I had no such luck.
Here’s why. See that big nut? It takes a 1-1/8-inch socket to remove, and there was no way to get a socket on it with the brake disc in the way. Underneath that nut is the head of a rod that the whole caliper pivots on. It’s the first time I’ve ever encountered brakes like this - there’s just one piston, and as it pushes its pad against the disc, it rocks the whole caliper, which brings the other pad into contact with the outer side of the disc. In this photo, the inner pad is still in place, and the outer pad has been removed.
Here’s what they look like once you finally get them off. I’m holding this one upside down, and you can clearly see where the pivot bolt goes through.
This is it stripped down to its essentials. The smaller hole is the bore where the hydraulically operated piston lives; the bigger hole above it is for the mechanical piston that shoves the pad against the disc. There’s a Rube Goldberg device between them that makes it all work, sort of on the teeter-totter principle.
I used a two-armed hone chucked in a variable-speed drill to clean up the hydraulic piston’s bore, using brake fluid as a lubricant.
Here you go: every single thing you need to rebuild a pair of rear calipers. Well, these parts, and about four hours or so. Inside the wadded-up paper are two new pistons.
Here’s a piston with its new seal. Not terribly big, are they?
The piston’s installed — you can just see the tip on the left inside the rectangular opening. The point on the right of the opening is part of the handbrake mechanism. Please don’t ask me to explain how it works.
Reassembly’s nearly done. The black things on top are flat steel springs. Under the two bolts is a hefty metal bar that … uh … well, like I say, it’s best that I not try to explain too much. Think pistons and levers, and you’ll have the general idea.
The whole mechanism is hidden under a steel cover, with a big rubber gasket to keep out the weather. The protruding bit with the silver star shape is the mechanical piston that pushes against one of the pads.
Back home again, complete with new flexible brake hose. You can see the end of the piston much better here. The brake disc will go onto that flange. I should have included a photo of the pivot bolt - it’s not simply a metal bolt through a couple of holes. Oh, no. There are three O-rings involved, to keep the elements out, and on the back end is a threaded cap. Seems like Girling put a lot of effort into making sure that these brakes wouldn’t need much attention.
Conventional two-piston calipers go up front. I had driven to Dirk Burrowes’ shop, expecting to pick up a rebuild kit for these, but Dirk and fellow Rover enthusiast Steve Manwell took the calipers out of my hands and rebuilt them there on the spot. Thanks, guys! Those shiny new pistons are made of stainless steel, so they won’t rust like the old ones did from moisture absorbed into the brake fluid. By the way, if you’re into Rovers, Dirk’s annual show is a not-to-be-missed event.
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