Hi! Thanks for the help with the CPS! Car is running ex now, 180k on it.
But it has a brake booster issue that I'd love to fix before I drive it regularly again. The booster is shot or something. Only has like, hard to push, manual brakes and from start up to shut off all you hear the entire time is fshhhhhhhhhhh. The whole time you drive, any time you ever go anywhere! Its crazy.

That cover is a you know what to get off! I tried, it seems I have to pry a lot of tabs to get it off. Are the brake boosters all the same or is there differences throughout the years/cars. This is the 97 lesabre.
Thanks for any guidance. If there is a write up, that would be sweet but I didnt find one. Thx!!

Sounds like a bad brake booster, maybe the diaphragm is bad, you'd have to pull vac on it and see if it looses pressure, it should only let air flow one way...

Ok, I understand so far WilliamE. Thanks for that too! Real quick question, could it possibly be a simple problem? Like a check valve or something else little? If it couldnt be anything else sort of like that, I'll start on a replacement of this one. And lastly, can I get a used one from "you pull it"?
Thanks!

I found a video that should help you to find out if the booster and check valve is working ok, I'd try these 3 things out first.


You have inspected the brake booster hose right?
Make sure it is not dry-rotting.

If it turns out the booster itself is bad you can replace it with a re-manufactured one for like 65.00, 55.00 if you send old one back, and get the core fee refunded.
ACDELCO 14PB4095 {#19286795} Professional Durastop; Remanufactured

After you do those tests let me know how they go, by then maybe somebody that has experienced this exact issue, and fixed it will respond with some tips.

Ok WilliamE, I will def post updates as I go. All the way to when it'* fixed and working right again. (hopefully real soon!)
I'll start with the test links you sent, then go from there. You've been a huge help lately, thanks a lot!

Based on the noise you are hearing and the fact the brakes are hard to push I suspect the vacuum hose to the master cylinder is loose or damaged.