I have an 05 mazda tribute, it hisses inside of car up under the brake pedel, it stops when you press the brake, i have narrowed it to a grey rubber/plastic boot, with some holes in it, with a foam and cloth filter, when i turned it, it stopped the hissing, but i have also pulled the boot off its seat so now i cant my hand in there to re attach it, please give me some advise, is this a replaceable part, or a part made to wear out?


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I had the same problem with my 01 tribute. I replace the master cylinder and brake booster. The master cylinder leaked fluid into the brake booster causing it to lose air. You will find over time it will continue to get worse and eventually pressing the brake will not stop it. It was a fairly simple job andI am a novice when it comes to cars. I purchased a repair manual and the parts and went to town on it. It took about 1.5 to 2.5 hrs I think.

 

our 01 had the master cylinder replaced 3 times under warranty but we never had a hissss sound.
thanks for help!

 

I'll confirm Jallen32's assessment. I had the exact same symptoms on my 01 tribute. I replaced the power brake booster and the problem is gone.

 

yes both of you are right on the money, i took it to the dealership to find out what the round grey filter is (see photo in first post), after 20min of searching the computer with no luckhe took my name and number and called me around 1.5 hours later. it is the brake booster ($400). but i can get under there and move it around and see its just a dirty filter. im going to take it off and see if i can manufacture a new filter for it. i will startanother thread to see if i can find someone that has done it before.

 

This is now happening in my 01 Tribute. I have the Hayne's Manual which thankfully has step by step directions, but there's a line under the brake booster removal that states "specialized" (or something like that) tools are required and that this work is not normally performed by a home mechanic. Can anyone confirm what that means...is it just a torque wrench that's "specialized"? Is it really that difficult? Given the other posts here, seems like it should be a pretty easy job. Found a good price on the part, now just need to do the work. Thanks.

 

It's the brake booster, my 02 Trib made this noise and replacing the booster fixed it. It's not too difficult, just four nuts on the inside of the firewall hold the booster in place; disconnect the pedal link and master cylinder and pull it out. You have to disconnect the brake lines and completely remove the master cylinder so be prepared to cap off the brake lines and replace some brake fluid that will leak out. Took about 1 hour going slow and paying attention to how things need to go back together.
Anyway good luck with it.

 

Thanks, Clockman. I replaced the booster this past weekend and the hiss is gone! I did, however, encounter another issue immediately following that may or may not be related involving the brake light switch. Please see https://www.mazdaforum.com/forum/mazda-tribute-22/brake-lights-stay-01-tribute-20318/ for details.

 

Glad to hear that issue is fixed, see my reply to your new issue in the other thread. Sounds like my luck; fix one thing, something else pops up!

 

Still can't get a hard pedal. Brake pedal hits stopping point and then pedal slowly goes to the floor...... What am I doing wrong, bled all brakes starting at Right rear???????????????????????????????????