Brake booster noise??

Weird cause this humming didn't occur until a week or 2 after I lifted the truck and bled the brakes. Maybe I'll just take it to a Jack Furriers and have them bleed the front and rear lines first.

 

Have you taken it to a shop by any chance? If so what have they said?? If it is the exact same thing I feel your pain. Its so annoying! The humming even changes tones when pushing the brake and lefting off. Its constantly humming/ringing when driving. Have to turn the stereo up to bypass the noise

 

Loosened my master cylinder up and no noise. After you shut your truck off and noise stops do you still have power assist the first time you step on pedal?

 

It could be caused by pushing the pedal clear to the floor. A movement the diaphragm was not used to.

 

Nope basically just lived with it for the past month... Hoping I don't die

 

I'm not sure I'll have to try that tomorrow. Dont forget the noise didnt start until a week or two after the bleeding of brakes. But then again by you loosening it one would think it would produce some sort of result? Very very frustrating man. I really appreciate you going out of your way and taking time to help me. Thank you my fellow Tacoma World friend.

 

One thing I have noticed. If I floor it WOT and stomp on the brakes... It does,nothing

 

Like a hard pedal?

 

Vacume is present on both sides of booster diaphragm until brake pedal is depressed. At that time vacume valve in booster is closed and atmospheric valve is opened. Vacume is on master cylinder side of booster diaphragm, atmospheric pressure on firewall side of diaphragm. Master cylinder to booster interface must be sealed.

 

Yep super hard... Actually has almost gotten me in accidents. But that started years ago..

 

Some have a seal around the rod itself.

 

Any updates?

 

Most of you guys know all about this. I just watched a good video for anyone else tuning in that's a noob like me:

 

No not yet. Going to take it in next week to bleed all the brakes.

 

This the seal that seals the master cylinder to the booster. When you pull the master cylinder out of the booster it stays in the cavity on the booster... you HAVE to install it on the master cylinder before you put the master cylinder back on the booster otherwise you will tear the seal as shown and have a vacuum leak. The symptoms are the brake pedal rises immediatly if you shut off the engine while you have your foot on the brakes. Another symptom is there is no "reserve" vacuum in the booster... you should get 2 to 3 assisted brake applications while the engine is off before the brake pedal gets hard. I put the paper gasket back on my master cylinder to booster flange.

 

If its leaking there the seal were the master cylinder slides in to booster is bad.

 

Actually just ordered a new master cylinder myself (aftermarket one by Centric 13044725). Would I need to order a gasket/seal to go between the master/c and booster? haha not even sure where to buy the gasket after searching around. Perhaps using RTV would be the ticket?

 

Technically that gasket is just to seal it from moisture getting in.

 

gasket part number. 47275-12020
https://parts.camelbacktoyota.com/oem-parts/toyota-cylinder-gasket-4727512020

 

Thanks Jon, always such a service to all taco-kind ! Grabbing one of those right away.

Looking up "cylinder gasket" for my model master cylinder and figured out I needed this one just in case someone else needs one for the same make: https://parts.camelbacktoyota.com/oem-parts/toyota-master-cylinder-gasket-4727524010

Its always tricky trying to find the exact magic words to search for to find exactly what you need, haha.