Brakes. The one major car component you should never mess with or take for granted. It’s the difference between getting your car smashed into the rear of a truck or nearly missing it by inches. One thing I always tell folks that ask is to never modify or do a half assed job of your brake DIY because the tolerance for errors is so low it’ll hurt. Whether it’s custom fitting a different larger caliper, swapping out brake pads or just bleeding the oil – do it right the first time.
On a less doom-and-gloom note, the other thing people always seem to complain about these days is slushy brake pedal feel.
“I bled my brakes and changed my brake pads but it still feels soft.”
Well, modern cars these days are made with two things in mind, cost savings and relative safety. Just by shaving off some weight or using thinner firewall material will result in massive monetary savings for the manufacturer and the car wouldn’t be any less safe to drive on the road. Good for the manufacturer, bad for the consumer. Why? Let me explain.
The brakes basically work like this :
1. You stomp on the brake pedal.
2. The pedal sends a signal (not literally) to the brake pump / brake servo.
3. The servo / pump forces or sucks air through the brake lines which in turn forces the pistons in the calipers to move.
4. The calipers clamp onto the brake pads which clamps down onto the rotors and stops the car.
Disclaimer : this is a highly simplified description of how brakes work. Don’t take it too literally, just understand the concept.
The biggest problem with all this and a soft firewall is that the brake servo/pump will move. Why? The amount of vacuum or pressure going through the whole brake system is enormous. The harder you stomp on the pedal the greater the pressure and that in turn flexes the firewall each time the servo/pump activates.
[youtube http://www.youtube.com/watch?v=a_Wo7F8W4To]
Stock brake servo moving on a stock Myvi
In the video, you can see the whole brake servo/pump moving and the camera was standing on a tripod not balanced on the car, in case you’re wondering. What does all this movement mean for you as the driver? It means a spongier brake pedal feel, less sensitive brakes and it makes it harder to modulate (gradual braking) the brakes.
Solution? Get a brake servo stopper. Since the Cusco and the Passo brake servo stoppers for the Passo (the Myvi equivalent) are ridiculously expensive, I thought I’d just to DIY this one with the help of a friend who just happens to own a metal fabrication factory.
First I had to find suitable mounting points for the brake servo stopper. You can’t just simply mount a stopper to hold the servo in place, the pressure from the servo might rip off the stopper from the mounted joints if it’s not mounted to a strong part of the car. After finding the suitable spots, I had to measure the distance between the mounting points and the tip of the servo/pump.
My friend being the big kahuna behind the factory had a lot of dormant metal bits and pieces lying around so he suggested to use this ribbed ultra strong piece of metal originally meant to be used in a heavy duty vehicle. A quick bend, a couple of drills and a twist later this was the final shape we managed to get to fit very nicely.
Success! It fit perfectly. A small piece of rubber was used to cushion the metal with the tip of the servo/pump just to avoid any metal-to-metal rubbing. Initial tests with the car resulted in fantastic brake pedal feel. Easy brake pedal modulation and zero sponginess. I was quite used to the need to pressure the pedal quite a bit so after driving the car around with the stopper, I found my brakes smoking… bad… whoops.
This ladies and gentlemen, is the one and only fully functional, non-fugly brake servo stopper for Myvi folks!
There’s a few kinks to iron out for the moment, but the current setup now is leaving me happy. Now that I can modulate the brakes better no more sudden or uneven braking head bopping from the passengers.
Mind you, does this little thing make my brake harder / faster / better? No. Well, better – yes, but harder and faster – no. You want to brake harder and stop faster, get bigger calipers. Or better brake pads. What the brake servo stopper does is just reduce the firewall flexing caused by the servo/pump movement.
Next up… DIY top overhaul!
