brake booster

[phenoyz]

hello again

Anybody knows if there is something wrong with the "power brake booster" ?

If you step on the brake pedal will it make a "hissing SOUND"? or will you hear
something else when you step on the brake pedal?

Will the brakes suddenly won't work?

http://www.automotix.net/usedautoparts/2008-toyota-yaris-power_brake_booster-inventory.html

'08 yaris sedan,auto

thanks

[cali yaris]

I'm very sorry, but I have no idea what you're asking about.

[kenkyd]

brake booster is silent. its only for the brake pedal. and if it stopped working, id say youd just have to push really hard. and ive never heard of one ever going bad

[phenoyz]

I'm very sorry, but I have no idea what you're asking about.


hello cali yaris

i went to the dealer , because everytime i step on the BRAKE PEDAL
i hear a little hissing/squeaking SOUND. is it normal to hear it
when i got my car last year i did not notice the sound.
the brake of the car is still good, its the sound that i am worry about...

dealer said that something's wrong with the "POWER BRAKE BOOSTER"?
its something like this:

http://www.automotix.net/usedautoparts/2008-toyota-yaris-power_brake_booster-inventory.html

i need to know if anybody had anything like this replaced

[phenoyz]

brake booster is silent. its only for the brake pedal. and if it stopped working, id say youd just have to push really hard. and ive never heard of one ever going bad

dealer said my brake might SUDDENLY STOP TO WORK????

DOES OUR YARIS MAKE ANY SOUND WHEN YOU STEP ON THE BRAKE PEDAL?
IS IT NORMAL TO HEAR A LITTLE HISSING/SQUEKY SOUND?
OR WHEN YOU STEP ON THE BRAKE PEDAL SHOULD IT NOT MAKE ANY SOUND

http://www.automotix.net/usedautoparts/2008-toyota-yaris-power_brake_booster-inventory.html

[cali yaris]

you keep saying step on the GAS PEDAL. I think you mean the brake pedal?

because the gas pedal has nothing to do with the brake system.

[phenoyz]

you keep saying step on the GAS PEDAL. I think you mean the brake pedal?

because the gas pedal has nothing to do with the brake system.


my bad....its the BRAKE PEDAL
coz dealer is charging me $1,100
i need to know asap if dealer is telling truth or not
thanks

[cali yaris]

exactly what is the $1,100 for? Do you have an estimate from the dealer?

Are you out of warranty?

[phenoyz]

exactly what is the $1,100 for? Do you have an estimate from the dealer?

Are you out of warranty?


the $1,100 is for the replacement of the "power brake booster" and labor.

I still have warranty, but when I bought the car from an independent
dealer last year it had an accident. thats why this dealer says they will not honor it because of the accident.
i had to replace the driver side fender.
i do not think the engine section got hit, only the driver side fender.

when i brake it is very strong. its the sound that it makes
when you step on the brake pedal thats worrying me.
its a small :hissing/squeaking sound: IS THAT SOUND NORMAL

I did not notice that sound until 4 weeks ago.

actually i just got came from a trip to san francisco and car was driving/brake like brand-new

They will be telling the truth right???because they are a dealership

thanks again

[2bad4u]

"They will be telling the truth right???because they are a dealership"

Yeh Right! I would get a second opinion, before dishing out $1100 bucks

[cali yaris]

Definitely +1.

I will ask my favorite shop how they would test that part. Don't fix something (especially for 1100 bucks, if you don't know for sure it's not broken.

[CTScott]

The brake booster works off vacuum. Shut the car off, press the brake pedal to the floor. Repeat. If on each additional pump the pedal goes less far the booster is fine. If you can continue to press it all the way to the floor either the check valve or the booster has an issue.

You can check the check valve by removing it and blowing through it. You should be able to blow through the threaded side (that screws into the booster), but not the hose nipple side (that accepts the vacuum line).

The hissing may be a vacuum leak in the hose, the check valve or the booster. The above will help figure out which...

[cali yaris]

^ excellent, YarisWorld FTW

[jamal1984]

The brake booster works off vacuum. Shut the car off, press the brake pedal to the floor. Repeat. If on each additional pump the pedal goes less far the booster is fine. If you can continue to press it all the way to the floor either the check valve or the booster has an issue.

You can check the check valve by removing it and blowing through it. You should be able to blow through the threaded side (that screws into the booster), but not the hose nipple side (that accepts the vacuum line).

The hissing may be a vacuum leak in the hose, the check valve or the booster. The above will help figure out which...

i'm planning to do some Seafoam Engine Treatment in my car, and the easy way is to taking the vacuum line from your brake booster PCV. can anyone tell me where is this vacuum line at?

thank you

[CTScott]

i'm planning to do some Seafoam Engine Treatment in my car, and the easy way is to taking the vacuum line from your brake booster PCV. can anyone tell me where is this vacuum line at?

thank you

It's just to the left of the brake fluid reservoir.

[johnancy]

I have the same noise. Hissing from under the dash. The brake very hard when cold. This has been going on for 6 months. I have had it to 3 mechanics all saying nothing was wrong. (Fobbing off a woman over 60) The car needs a good run!
I did a 700 klm return trip to Canberra.

There was something wrong. Very frightening in busy Sydney traffic when the brake fails altogether!!

Now the Yaris is at the dealers. Towed, as car deemed as dangerous. Complete failure of the brake booster.

Why do women get fobbed off? I knew there was something wrong and getting worse.

Thank goodness that nobody has been injured. There have been a few close shaves.

[yaris2010RS]

my moms 01 Camry had the same noise. after a over $1,500 quote i looked at it myself and i lucked out. i found the leak was coming from the seal between the master cylinder and booser. i just tightened the master cylinder to the booster (2 screws on either side of the M/C) and the sound just about went away. if the sound comes back i will change that seal but i am afraid to open that up.

The brakes will never just give up. the booser is there to assist you, yes is assists ALOT, but in the event of a loss in pressure the pedal should still bring the car to a stop, the use of the e-brake will definatly be required.

[Bob@MorganBingham.Com]

2010 Yaris Sedan - orignial purchaser.
Dealer has brake booster on order to replace under warrenty. Symptom was a sound the Toyota mechanic had "never heard before from the transmission side of the engine" when pulling to a stop. This was a type of intermitent hum.
Note: A British classic sports car mechanic thought it was a "vacuum sound."
The Yaris brake booster on my checking the forum, does seem to work on a vacuum principle.

[Bob@MorganBingham.Com]

2010 Yaris Sedan - orignial purchaser.
Dealer has brake booster on order to replace under warrenty. Symptom was a sound the Toyota mechanic had "never heard before from the transmission side of the engine" when pulling to a stop. This was a type of intermitent hum.
Note: A British classic sports car mechanic thought it was a "vacuum sound."
The Yaris brake booster on my checking the forum, does seem to work on a vacuum principle.
FOLLOW UP - noise persisted after Toyota replaced brake booster SEE "Humming Yaris"

[Geoff Peace]

The brake booster works off vacuum. Shut the car off, press the brake pedal to the floor. Repeat. If on each additional pump the pedal goes less far the booster is fine. If you can continue to press it all the way to the floor either the check valve or the booster has an issue.

You can check the check valve by removing it and blowing through it. You should be able to blow through the threaded side (that screws into the booster), but not the hose nipple side (that accepts the vacuum line).

The hissing may be a vacuum leak in the hose, the check valve or the booster. The above will help figure out which...

Agree with the above. Also with the engine switched off press the brake pedal several times to exhaust the servo. (brake booster in US I think) Then with firm pressure on the brake pedal start the engine, the brake pedal should go down a little further as the servo assists the foot pressure. If this is so all is fine. The servo is simply two chambers with a diaphragm between. When in use, one side is in vacuum, exhausted by the inlet manifold, the other is normal air pressure which provides the assistance.

Regards Geoff Peace.