Brake pedal sound

[bgwolfpack]

My brake pedal has a strange noise and feel when the engine is still in its warm up cycle. When the pedal is depressed it makes a whooooshy/bubblley sound each time. This doesn't seem to affect the braking ability of the truck at all and the noise goes away after warm up. Has anyone felt this also.

Is it something to be concerned about?

[The Roadie]

Listen very closely under the hood and see if you can localize it to the master cylinder or the vacuum boost diaphragm. I've never heard of that sort of noise in my truck or on the OS in my time, which was from before it was even called trailvoy. Sorry.

[scottp8113]

Does it come from the engine area or the actual pedal? mine makes a similar wooshing noise when I push the brake pedal as does my dad's suburban.

[bgwolfpack]

Just spent a few minutes with a neighbors help. The sound is localized inside the cab with the brake pedal its self. There is no unusual sound from the master cylinder. It seems to be the actual linkage through the firewall. I hit it with some wd-40 and it made no change.

Does it come from the engine area or the actual pedal? mine makes a similar wooshing noise when I push the brake pedal as does my dad's suburban.

It has the whooshing. That I think I understand especially when cold.

It's the bubblley sound I can't seem to locate.

If the connecting rod from the pedal to the cylinder itself was plastic the noise would make sense if it was binding with something else.

The sound really sounds like flatulence.