club.liberty.asn.au

Just dropped my car off at Cromwood Auto in Burwood (decided to give it a try after only using Subaru since I got the car) and mentioned my brakes were spongy and thought I needed new pads. He drove the car a little up the driveway, tapping the brakes as he did so and then told me that the brake booster may be gone and it could cost up to $1,000 to repair!

Forgive my mechanical ignorance, but could anyone tell me what the brake booster is, what may happen if not fixed (besides the obvious crashing into a tree jokes) and ball park pricing (if known).

Any help/assistance would be greatly appreciated.

I can't see worn pads causing a spongy feel.
Usually that just indicates there is some air in the system, and it needs bleeding.
The "brake booster" is a mechincal unit that amplifies the pressure from the brake pedal, so you don't have to press so hard to apply the brakes.
It uses vacuum pressure from the engine to do this.

if the brake booster totally fails, your pedal will go harder, not softer. Try rolling down a gentle hill without the engine running, and apply the brakes a couple of times. You should get two normal applications, then the pedal will go much harder and it will take a lot more force on it to get the same braking effect. This happens when all the vacuum has been used up.

Is the car still braking just as quickly? is it just that the pedal feels a bit softer under your foot?

Take it to brake specialist....

Bob.

Ric wrote:I can't see worn pads causing a spongy feel.

if the brake booster totally fails, your pedal will go harder, not softer. Try rolling down a gentle hill without the engine running, and apply the brakes a couple of times. You should get two normal applications, then the pedal will go much harder and it will take a lot more force on it to get the same braking effect. This happens when all the vacuum has been used up.

Is the car still braking just as quickly? is it just that the pedal feels a bit softer under your foot?

Thanks Ric. The pedal is definitely softer, not harder. It's more that after it the brakes bite, the pedal then has a second movement where it sinks down towards the floor. I haven't braked hard, since they started feeling spongy and I generally lightly pump the brakes when I brake.

moggy wrote:Take it to brake specialist....

Bob.

Cheers Bob, depending on what I get quoted I may have to.

Ross knows his scoobies very well so I'd trust that if he says that's what he thinks it could be, then he's entirely genuine.
Perhaps get your brakes bled properly with some good fluid and see the result?

imania wrote:Ross knows his scoobies very well so I'd trust that if he says that's what he thinks it could be, then he's entirely genuine.
Perhaps get your brakes bled properly with some good fluid and see the result?

Thanks for the advice Ain. I'll take him at his word and depending on pricing time etc., raise the above suggestion. Hopefully it is just air in the lines or some other less serious thing. I really do not want to have to shell out that kind of cash at what I thought was going to be a routine service.

Corsair wrote: The pedal is definitely softer, not harder. It's more that after it the brakes bite, the pedal then has a second movement where it sinks down towards the floor. I haven't braked hard, since they started feeling spongy and I generally lightly pump the brakes when I brake.
...

A spongy feel as soon as you press usually indicates air in the lines.
Sinking after you press sounds more like an internal leak, either in the master cylinder or the booster.

Ric wrote:

Corsair wrote: The pedal is definitely softer, not harder. It's more that after it the brakes bite, the pedal then has a second movement where it sinks down towards the floor. I haven't braked hard, since they started feeling spongy and I generally lightly pump the brakes when I brake.
...

A spongy feel as soon as you press usually indicates air in the lines.
Sinking after you press sounds more like an internal leak, either in the master cylinder or the booster.

Thanks Ric. The more infomation I have, the better equipped I feel. Hopefully, such a leak isn't an expensive replacement job...

Just got word from Ross. It is the brake booster. Shee-it. How much am I going to be up for and will it be dangerous to drive until it gets fixed?

Corsair wrote:Just got word from Ross. It is the brake booster. Shee-it. How much am I going to be up for and will it be dangerous to drive until it gets fixed?

Mick (dr20t) is selling a second hand one for $100

seanmau5 wrote:

Corsair wrote:Just got word from Ross. It is the brake booster. Shee-it. How much am I going to be up for and will it be dangerous to drive until it gets fixed?

Mick (dr20t) is selling a second hand one for $100

I am meant to be collecting the car in about half an hour and Ross said he's trying to source 2nd hand. I'll see what he says and then maybe PM dr20t tonight. Thanks for the heads up.

A bit of a late post, but if you're having to replace your brake booster, why not take the opportunity to source a second hand STi Brake Booster and Master Brake Cylinder and get them fitted for a 13% increase in firmness and clamping force?

My STi BB and MBC (that I haven't fitted yet) cost me $150 together off eBay. Any wrecker should also be able to help.

Your model has a twin stage booster,it is designed for emergency braking and will go softer with hard applications,thats why you feel the 2nd application.Compare it with the same spec as yours before wasting your cash.
Cheers Eddie

I have an STi one from a GDB sitting in my garage.

$50.

cruisn wrote:I have an STi one from a GDB sitting in my garage.

$50.

Thank you. PM Sent.