I hear air when I depress the brake pedal, and I notice that the pedal goes down way more than it used to. Also, I don't seem to have as much brake stoppage as I used to have. Does that air noise mean that the brakes need to be bled?

FYI - the car sat up for more than 3 months when it was being repainted. Before the repaint, the brakes worked very well and I suspect something happened while it was inoperable. Any thoughts?

 

Hello'

Did you check the level of the brake fluid in reservoir? Low fluid level would indicate a leak leading to a soft brake pedal. Brake fluid is not a consumable. There of course could be other causes.

 

Yes, the brake reservoir is completely full of fluid.

 

Sounds like air in the lines. Get them bled as that's the easiest place to start and go from there if that doesn't fix it.

 

Hello @desiled ,
When you say you hear "air" when you press the brake pedal, is the air sound loud and clear inside the vehicle, or is it outside in the left fender area, firewall steering rack area, or at the brake booster itself, as having air in the lines (in need of bleeding) could not be heard by pressing the brake pedal.

I believe it is either a leak in the vacuum lines from the engine or the vacuum pump that supplies vacuum to the brake booster for proper operation that have a leak, or, it can be the brake booster itself, my brake booster actually started leaking during my rebuild shortly after installing the engine transmission package, I bled the brakes and all seemed somewhat fine, but the pedal was still a little soft to my feel, the pedal also went a little far for my liking, especially with all new pads and rotors, but being it was in the shop with the exhaust not fully installed, I didn't hear the vacuum leak until I installed the full exhaust and pulled it outside, I could hear a slight hiss from under the dash, the next thing I knew, I had brake fluid dripping down onto carpet, I also found a slight amount of brake fluid dripping from the bottom of the brake booster at the cowl area, eventhough the reservoir didn't show any decent amount of loss, as I stopped pressing the pedal the second I saw it drip in the interior, and made a video of it, but I then put towels on the carpet so I could make the video showing the leak outside at the booster, in the booster video, you can hear the fluid inside it, so, the bad seal in the master cylinder allowed brake fluid to eat at the booster diaphragm, therefore causing a vacuum leak, along with itself dripping fluid.

A body paint job should not interfere with any of the braking system, unless you had other work involving said system performed, they didn't do any paint work at the cowl area, did they, if so, did they remove the master cylinder and booster ?















Johnny

 

Johnny,

This is wonderful information. You mentioned that a spot occurred on your inside driver carpet. A spot also appeared on my driver floor mat that I know shouldn't have been there as we never get in with muddy shoes. I tried to carpet clean the spot. Most of it came out but there is still a slight notice of it on my tan carpet.

I sent a message to my mechanic, and he suggested the brake booster may be bad, so I think I've found the issue answer. By the way, I've searched online, and I found Bentley brake boosters for around $200 (Scuderia was $1,000). What should I pay for the booster?

Thanks again for your info. You are good.

 

Update

I purchased a brake booster from Scuderia, and my mechanic installed it. He said he bled the brakes 2 or 3 times to make sure there was no air in the lines.

I notice when the car has not been driven for a couple of days, I can get in before I start the car and depress the brake pedal, and it feels solid. However, after I start the car while holding the pedal, immediately the pedal loses pressure and goes to the floor. Also, I still hear hissing air when I depress the pedal while the car is running. I do have some braking but nothing like before all my issues started and with the pedal going to the floor, I have to pump the brakes for really good stopping.

My mechanic wants me to drive the vehicle for a while. He said the ABS system would build pressure and should improve the pedal. I'm not buying that logic. Something is still wrong, and I've spent $3,100 and still have the same issues.

Any thoughts from the forum?

 

Hello @desiled ,
You say that you replaced the brake booster, but did you replace the master cylinder as I showed in my pictures in my previous response ?

As the soft pedal and or any brake fluid leakage through the booster into the interior, that is caused by the master cylinder internal seals failing, which then allows the fluid to leak into the booster, then the interior onto the carpet, did you determine the stain on your carpet to be brake fluid ?

Also, a failed master cylinder causes a soft pedal, as the failed internal seals allow blow-by of the fluid instead of building pressure to the lines, abs module, then onto each caliper.

Lastly, did your mechanic use the proper diagnostic tool such as Ross-Tech / ODIS VAS 5054 to access the ABS module to open valves for proper bleeding of the system ?

Johnny