Hey guys, this is my first post. I have a 1997 Chevy Blazer 4.3L with just about 190,000 miles on it. Currently I am experiencing a brake issue. Here are the symptoms:

When the brake pedal is pressed there is a whooshing sound.
The brakes don't quite work as well as they used to but they still work well
When I press the brake pedal, the idle on the engine drops but doesn't die.
Brake fluid level is good and I don't see any leaks.

On a side note, the check engine soon light comes on but it has always popped on and off since I've owned it. It only turns on if I drive over 70mph. As long as I stay under 70mph, it will stay off.

After reading several posts I came to the conclusion that it was either the brake booster or a vacuum leak. I checked the vacuum lines but didn't find any leaks. I took a good hard look under the dash at the brake pedal and did notice what might be the issue. I'm not familiar with what this part is called but when you push the brake pedal down it compresses what appears to be a rubber piece which connects to the wall. It looks like it should be sealed to the wall somehow but it is not. I can move it back and forth and rotate it easily.

When I push the brake pedal down it causes the rubber piece to compress. As this happens you can hear the whoosh sound which again leads me to believe it should be sealed and not moving. Is this assumption correct? If so, is this my vacuum leak?

What is the name of the part and how hard would it be to replace if needed? Or can I somehow seal it back in place?

Thank you in advance and apologies for my lack of knowledge regarding the Blazer. I just picked it up about 4 months ago and am still learning my way around it.

 

Update - Ok, now I feel like an absolute idiot. After further research it appears that the piece the brake pedal pushes down on is part of the brake booster and it would appear that it is torn. I have attached pictures of it below. Image 1 shows the brake booster, image 2 shows the brake booster when I've slid it away from the wall, and image 3 shows the brake booster slid back to the wall where I think it is supposed to seal. I don't understand how it could tear away like it did. Can it be reattached or do I need to replace the whole booster?

 

Anyone have any input? I'm trying to figure out if I can safely drive the Blazer with this issue for at least another two weeks until I can afford the part. It's my daily 40 mile round trip driver to work. I still don't even know if the way the piece in the pictures moves around is normal or not.

I've used the search function and I've read 38 pages of posts in this forum looking for more info. All I've found is that I could have a bad brake booster based on previous posts but I don't know for certain if that is the case or if there's something small I might be over looking.

Any confirmation would be greatly appreciated.

 

your brake booster is busted, this is also causing the vacuum leak, you can drive it but be cautious, you wont be able to stop as easily/quickly. replace it as soon as you can.

 

yeah i had a booster blow out on my completely in a k5 blazer, towing a empty car trailer. its a lot of work to stop it without power brakes but i drove it home like that

 

Thanks for the reply! Before today the braking wasn't too bad but as of today it took a turn for the worse. Braking became very difficult and I stalled out twice on my drive home from work. Will this continue to get worse? At this point it feels like another day or so and it's just going to quit on me.

Also, my check engine like has always come on when I go over 70mph. It will always turn off if I just drive around town a bit and then park it for a while. I broke 70mph this morning on my way to work today so the check engine soon light came on. Once that happened is when the idle really got bad. I'm hoping that tomorrow the check engine soon light will be off and it might run better. Any thoughts on that?

 

not sure about the light but the vacuum leak is why it might stall. if you wish to challenge fate you could block off the vacuum line to the booster, but you will no longer have power brakes. need a scan tool to see what the check engine light is about.

 

I am guessing the light is from the vacuum leak but then why it only happens over 70mph has me at a loss. The engine also stutters at between 48mph and about 56mph. When I take it in to get the brake booster replaced I plan on getting it scanned. That's going to be a few weeks though. I'm just hoping it starts every morning and gets me to work!