Brake Caliper Rebuild

It was time to continue the rust fixing so I drove the Mustang back to Tampere. I joined my friend in the garage for an evening and while he began working with the rear wheel arch, I decided to rebuild the driver side brake caliper. The passenger side caliper had been dragging so I rebuilt it during winter. After that the driver side started dragging. I should have done both at the same time...

When rebuilding the passenger side, I learned that pulling the pistons out could be pretty difficult. This time I used the brake pedal to push them out before removing the caliper. I pulled the brake pads and applied some pressure while my friend made sure all pistons came out evenly. Next I could remove the caliper and sand blast it clean. Then it was finally time to disassemble it.

Unfortunately the cross over line snapped in half while I was taking it out. It had corroded pretty badly and the end fitting would not even turn any more. At this point I was extremely happy that I had bought new lines a few weeks ago. A disaster avoided!

I removed the old seals and cleaned everything as well as I could and it was time to put the caliper back together.

I had new Raybestos seals and four new pistons. After pushing the seals in their grooves, I lubricated the pistons and pushed them in. The new cross over line needed some bending but otherwise assembly went smoothly. I bolted the caliper back to the car and then applied some silver paint on it.

I had also bought new braided brake hoses but couldn't start using them yet. It seemed that the brake line fitting on the car was also pretty corroded and would most likely also break the line if I tried turning it. I'll have to replace the lines later before installing the new hoses.

Fixing The Brakes

The right front brake had been dragging after I swapped in new pads. This would have to be fixed before driving the car again so I got to work. I unbolted the caliper and took the hose off. With the parts on the table I disassembled the caliper to see what was wrong. This became apparent when pulling out the pistons. Two of them came out quite easily but two were badly stuck. I could not get them out myself but my friend welded a pipe to them and used it to twist them out.

Someone had used force to get them out before and there were large dents in the pistons. I decided to replace all four and naturally install new seals too. When the parts arrived, I also cleaned and painted the caliper.

I placed the new lip seals in the caliper bores and pushed the pistons in. I lubricated them a bit but still one of them was pretty tight. I could not find anything wrong so I pushed a bit harder. I really hope it will not be stuck again when using the brakes later... With the caliper assembled, I installed it back to the car.

I hope I'll be driving my Mustang quite a lot during summers so I also decided to upgrade the master cylinder to dual bowl model. With the original single bowl, if one of the hoses fails or one seal starts to leak, I could lose all brakes from the car. The dual bowl cylinder has separate fluid reservoirs for the front and rear so at least one should always work.

This is a really common upgrade so I could just order a new ready made pipe kit and cylinder for my car. Auto Resto Mod has also made a good video of the swap so I followed their instructions.

Installing the cylinder was simple but the pipes weren't even close. I guess they might have installed the parts in different places at the factory so I just bent the pipes until the ends were correct. Then I screwed everything in and hopefully I will have good brakes in the future. I still have to bleed them later though...