2/26/10
Braking Options

I’ve been pretty busy this last couple of weeks working on a 275GTB restoration in between battling winter storms one after another. This week, I finally got a chance to work on my Ferrari!

I’ve been spending a lot of time thinking about the brakes and things are starting to point to the brake booster as part of the problem that I encountered on my trip to Florida over a month ago. Even though one front rotor heated up enough to set the rubber brake hose on fire, there was no proof both front brakes were not locked up. By the time the fire burned through the soft brake hose, the pressure was released so nothing definitive could be found right after the fire. When I replaced the soft hose, both brakes were locking up.

I didn’t have time to troubleshoot the problem in Florida, but two clues point toward the booster being the problem. At one point, when we were trying to figure out why the brakes were still locking up, I had Mark Dempsey pump the brakes. Every other time, all the brakes would lock up. He found if he stabbed them a certain way, a sound would come out from the booster assembly, and the brakes would release. I think something was hanging up inside the booster.

The second clue was when I bypassed the front brakes to get my car to the lawn of the Breakers, the rears began locking up as well. With the front brakes disabled and the equalizer out of the mix, the only two things left that could have anything to do with brakes was the master cylinder and the booster.

This booster was rebuilt with the brake system, but when I looked back at this website I found that to be nine years ago! Wow, time sure flies.

The master cylinder was purchased about the same time, but recently received new seals.

The one piece to my brake system that has not been rebuilt or looked at is the booster/equalizer mounted behind the radiator down by the lower radiator hose.

After speaking to several Ferrari shops about this equalizer while I was at Cavallino, there seems to be a mix of things people do with these things. I’ve written about this unit before, and what I learned can be found here, but I found some shops gut these units and disable the booster section of this unit making it simply a tee. Other shops rebuild these units with new seals. The shops that eliminate this unit find very little difference in braking power and find eliminating a failure prone unit reassuring.

I have several ways to fix my Brake System, and I’ve made a list of options:

1. Rebuild the brake booster, and see if the brake equalizer can be rebuilt. I’m not a fan of this option because I’m not too confident these two units will work with any longevity. Having rebuilt my booster once before and to have only gotten a few years of service is not my idea of having a reliable brake system.

2. Eliminate the booster/equalizer unit down by the radiator by either converting it to a tee, or plumb new lines for a simple tee. Disassemble the Bonaldi Booster and try to figure out what broke.

3. Eliminate the Bonaldi Booster along with the booster/equalizer and try to create a manual brake system. I don’t know if the current 1 inch master cylinder will provide enough pressure to stop the car, but eliminating these two unreliable units will make the brakes more dependable. Depending on the amount of pedal pressure on a manual brake set up, I may have to change the bore size of my master cylinder. I’ve been looking at the Wilwood website. If anyone has other options, please e-mail me.

4. If I’m going to make major modifications on my brake system, maybe I should consider going to a dual circuit master cylinder. GTEs and 330 Americas have a single master cylinder, and if I were to loose one brake line, all the brakes would fail. A dual system gives a second circuit to stop the car if pressure is lost in one of the lines. Unfortunately, I’ve only found 1 inch dual circuits, but the search continues.

I can easily leave all the original equipment in place so it will all look original, only the system will be much more reliable and long lasting. As I disassemble the brake system, I’ll keep you informed which way I will go!

Previous Restoration Day
Next Restoration Day
Home page