I have front disc & rear drum brakes on my 85 olds delta 88 & when i press on the pedal i hear a swooshing sound. The fluid level seems ok & no leaks. The pedal doesnt go all the way to the floor & the brake light does not come on. When the car is off i also hear a swooshing sound when i press on the pedal. The brakes do seem to work fine. Whats going on ?

 

First question, is this something new that has just developed?
For the most part in most vehicles with stereo turned off you will hear a swoosh or similar sound when you depress the brake pedal!

Pat

 

+1.

Do you hear the sound the whole time that you hold the pedal down, or only while you are moving it toward the floor?

- Eric

 

Only when i move it towards the floor. I noticed the sound with the stereo off last friday.

 

+2 Sounds normal to me.

 

Turn the stereo back on!

 

That's the normal sound of the booster working.

- Eric

 

Perhaps your booster has a pinhole leak, or is leaking from behind (where the brake pedal linkage goes trough, there is usually a plastic or nylon shield that goes through the firewall). The fact that the brakes still seem to work with proper boost may mean it is insufficient to prevent the booster from accumulating vaccuum while the engine is running.

 

Is the pedal travel more than you have noticed before? My wife had complained that occasionally the brake pedal on her '86 Wagoneer would go to the floor with no brakes until pumped. When I drove the vehicle I could not duplicate the problem. After the vehicle sat for two months I went to drive it just to keep it moving and noticed that though the brakes did work, a woosh and excessive pedal travel was clearly evident. A new master cylinder and brake bleed improved the braking greatly. If you feel excessive travel, or suspect a problem I think that an o/h master cylinder is cheap insurance to avoid a potentially catastrophic scenario. A loss of brakes in traffic at 70 mph will get your attention (and pedestrians) very fast. I'm not insisting that anything is wrong,.....just follow your mechanical instincts and continue to enjoy your Olds..

 

What if the fluid level is not full & low just a little bit ? The braking power seems good. The noise sounds like its under the dash near the pedal.

 

My cousin whos been a mechanic for over 30 yrs checked out my car last week. He said that "swooshing" sound is normal the booster & master cylinder is good (No loss of brake fluid). The brake pads & shoes are good as well. I myself feel the brake lines need to be bled but my cousin said they dont.

 

Well, there ya go. It's nice to be reassured.

(And if you really want to bleed the brakes, you always can... )

- Eric

 

After having to replace my proportioning valve due to a clog I have found out from brake and fluid/oil experts that you should flush out your system with new fluid every 5-7 years. Most systems will develop moisture (water) over time. That is not good for the system and can cause internal rusting of the lines. On top of that dirty fluids does not preform as good.

I am changing the fluid on all 4 of my classics this weekend.

 

If the brakes are fine otherwise, I vote for a deteriorated silencer. On the back of the booster under the rubber "boot" where the actuating rod goes through, there's a silencer to muffle the "whooshing" sound it makes when the brakes are applied. Usually made of felt or breathable foam.

 

I did not know that.

- Eric

 

My cousin says unless the swooshing sound bugs me i could leave it be. Leaving it alone will not hurt anything or cause damage. What does dirty brake fluid look like ?

 

Correct.
Not clear.

- Eric

 

Learn something new every day. I always thought they were just there to keep dust and dirrt out.