How to rebuild brake calipers | Project Elva sports racer

At least the early Elva Mk VI sports racers–our 1962 model carries chassis number 13, meaning it can be considered an early example–were originally all equipped with drum brakes. However, many were converted to discs, either early in their careers or more recently when being restored for vintage race duty.

Our Elva is no different; our Mk VI is equipped with a combination of early Spitfire calipers and what appeared to be Herald or Spitfire front hubs that have been modified to the correct 4x4.5-inch bolt pattern for the Elva wheels.

We have been told the original front brakes were Triumph TR2 or Hillman, or even early MG. While we are still in the process of finding the correct drums, we will start with the disc brakes that came with the car first.

In all honesty, while we do want to acquire the original drums for concours duty or if we get lucky enough to be invited to Goodwood, the discs are simpler, lighter, safer and perfectly legal for most racing in the U.S. since so many Mk VIs were updated with them back in the day. Here’s how we restored the calipers for our Elva.

We determined that the calipers that are on our Elva project were from an early Triumph Spitfire. While most likely not original, they are close to being period-correct and would have been an inexpensive, easy and logical choice back in the day. Thankfully they were not in bad shape either.

The first step is to carefully put air pressure into the caliper. This will usually loosen and pop the pistons out against the calipers. At that point, you can remove the clips and pins that hold the pads in place and then remove both the pads and then the pistons.

With the pistons removed, you can easily get to the seals with a small pick. Unless things are leaking, there is no real reason to separate a caliper into its two halves.

Here’s what we ended up with. Brake cleaner and penetrating oil are your friends, especially if the pistons are rusted and won’t come out. At this point, we can clean and rebuild the calipers with new rubber parts.

An ultrasonic cleaner is a wonderful tool to clean almost everything, including brake calipers. We were surprised how new these beat-up old calipers looked afterward. More importantly, the ultrasonic cleaner will clean out the passages in the caliper, too. If you don’t have such a cleaner, you can fight through the cleanup with brake cleaner alone.

Here are the new seals and dust boots sourced from Moss Motors, along with the original pistons. These pistons cleaned up like new with some #0000 steel wool and a bit of brake fluid.

Our calipers are now rebuilt and touched up with a bit of high-heat paint from POR-15. Remember, when you are assembling calipers, use brake fluid to moisten the seals when pushing the pistons back into the calipers. Paint your calipers afterwards, being careful not to get paint on the dust boots. Why? Because brake fluid will destroy your fresh paint job.

For brake pads, we used Porterfield’s R4-1. Developed using knowledge testing in the vintage racing community, these pads were designed for conditions where very high friction is needed with minimal warm-up time and in applications where there is difficulty in maintaining sufficient heat (such as in very lightweight cars) with conventional race pad compounds. These pads also offer great modulation, consistent pedal feedback and are rotor friendly.

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