1975 Toyota Celica wheel cylinder repair

Our Chump race car in progress made its way back to the shop from the roll cage fabricator this weekend. However as we loaded it on the trailer the rear brakes suddenly failed. I am glad it was while loading on the trailer and not in a race.

Back at the shop, I inspected the car and found evidence of a fluid leak at the left rear wheel. I found this odd as I had just installed a new wheel cylinder on that corner before sending it to the shop.

To remove, I first removed the wheel. Then there is a Phillips head screw that has to be removed. I remember that the first time I removed this screw, I had to use vise grips to avoid stripping out he crossed recess. This time I used a Phillips bit in a ratchet to get it loose.

I used two 8mm bolts in the provided holes to jack the drum off the axle hub.

With the drum off, I could see that the new cylinder was indeed leaking.

I used a 10mm line breaking wrench to loosen the brake line and then removed the two mounting bolts that also have 10mm heads.

I then wiggled the cylinder out from between the shoes.

I pulled one of the pistons out and then the rubber seal behind it. I checked the rubber closely for cuts or notches. I then inspected the cylinder itself. There I found a lot of debris. Possibly rust from the old brake line. I was able to clean the cylinder and replace all the parts. I reinstalled the cylinder and bled the brakes. It is holding for now, but I suspect we need to do a full brake line flush before we race the car.

Update: The brakes were still soft so there was still air in the lines. I set up my pressure bleed system and completely removed the bleeder screw. I ran several ounces of fluid through and got some nasty stuff out. I put the bleed screw back and bled some more fluid before sealing it off. For now I have a firm pedal again.