SeptoseZero

Alright, I'm new here, so go easy on me. My question is this, I have an 89' C4 that the brake pedal emits a hissing and has a ton of resistance when attempting stopping power. The issue is constant, and makes it practically impossible to drive. I suspect its likely the brake booster because when I try to hold my foot on the brake and start it, the pedal doesn't try to move to the floor and gives a bit of resistance. The booster is OEM and I already made the mistake of buying an replacement before asking around. Is there anything else this could be? I plan on taking it to a shop this weekend and having them replace it, since I just don't have the time to turn wrenches like I used to. I'm just concerned with taking it somewhere and the shop trying to get one over on me. Christmas being around the corner, I'd like to do this as cheaply as I could, so if theres anything you guys know that are likely another cause, I'd love to hear it. Just asking for discussion, I know you would have to actually put eyes on it to diagnose it properly. I love my Black Betty, she's only got 40,000 miles and I want to take care of her. lol.

Thanks!

s carter

From what you have Described, Hard Braking, Hiss with Foot on Pedal, With Foot on Brake no dip of Pedal when started. I feel the Booster is Bad and a new one is needed.

jagvette

Check the vacuum pipe to the booster is working, I would disconnect it with the engine running to see if it is 'sucking' if that's OK I would suspect the booster, I just replaced mine with a metal one I got on Ebay and now my brakes work great the plastic ones often split even when new.

crowz

This covers the booster, how it works and how to diagnose it.

http://crowz.narmir.com/vehicles/198...repair/brakes/

L98-C4-HI

Cool link, thanks! My pedal is more than firm and slightly dead feeling. Looking at the booster it says it's a GM Australian part so it must've been changed somewhere along the way. Kind of odd yes?

belairbrian

The symptoms you describe are the same ones I had on my 92 when the booster failed.


No vacuum from the engine would cause a hard pedal but would not cause the hissing sound.


As to the Australia thing. Mine was marked the same way. It is my understanding that the boosters were made there and shipped to Kentucky.

belairbrian

As far as a shop getting over on you.


If your supplying the part the only cost should be labor. I did mine in about 4 hours having never done it before, an experienced shop should be a little quicker than that. I did not have to disconnect the master cylinder, so there was no need to bleed the brakes. If they aren't familiar with corvettes they might remove the MC and thus more hours.


Since your supplying the part, if it's the wrong one and doesn't fit, that's on you. Maybe post up the brand and part number you bought. Someone may know if it fits properly.

Aerovette

Could be the check valve.

http://www.oscaroparts.com/dorman-po...SABEgJrgvD_BwE

ddahlgren

An Aussie one is OEM.

Cliff Harris

The original brake system is made by PBR, which is an Australian company. The exception to that is that the ABS system is made by Bosch.