A brief intro to my current situation: I bought my corvette off of Facebook marketplace for my 18th birthday, and I went on a test drive a week before I had bought the car. Everything seemed smooth with the car, and back then I didn't really know too too much about cars, but after I bought the car I had to get it inspected to get it registered. I went to a Chevy Dealership and asked if they could inspect the car for state inspection and they called me later that day and told me all the sorts of issues they found with it. For starters, it didn't have a catalytic converter on it. I had them add one on so my car would pass state inspection but I didn't want them to do anything else to the car, just get it to pass state inspection, mostly because I couldn't afford the whole repair at the time. About two or three weeks ago, I thought my clutch had died because on my way home from work at night my clutch pedal was very limp and I had to force the pedal all the way to the ground before I could shift gears. I then realized it was actually the clutch master cylinder that needed to be replaced, so I bought the part and replaced it. The clutch feels a lot better than it did before now, but as I was driving it to make sure everything was fine, I was slowing down at a light and my brake started hissing, and I had to really force the brake down before it would slow the car down. The car also has an exhaust leak from the headers to the exhaust because one of the bolts on the passenger side broke off and I couldn't screw another one on the driver side, but I'm going to be getting a new header for the car soon and possibly a new exhaust but I'm still debating it. But I'm hoping someone can possibly lead me in the right direction to help me fix my brake problem. I believe it's either my brake booster or master cylinder or a combination of both but I'm no car expert so I'm not 100% sure. Here are some images of the car as well:

 

Those symptoms point to a failed brake booster, but check a couple things before replacing any parts. There's a hose from the check valve located on the booster. Make sure it's not cracked or otherwise leaking, and that it's firmly plugged into the check valve and the vacuum source. Other than that, with the car off, step on the brake pedal and start the car. You should feel the pedal sink down a little. If not, and you hear a hissing when you push the brake, I'd suspect a failed booster.

 

Welcome to the Corvette Forum ZiggoMC!

First thing you NEED to be able to work on your Corvette is a copy of the Factory Service Manual for your specific year. Helm Publishing sells the hard cover, Fleabay will sell you a DVD with the manuals on them for a fraction of the $80 the hard copies cost. But you will need to have one so get one before you go too far.

If you are hearing the hissing inside the Corvette could it be possible that the brake switch for the cruise control is leaking inside the Car when the brake pedal is pressed? I remember the vacuum hoses down there were leaking on my C4 when I bought it. I ended up replacing a lot of vacuum lines as they were crumbling in my fingers. I guess it really depends on where the hissing is coming from.

It does sound like the booster but I would check just to be sure before replacing the booster, that is a "Project". I would want to be absolutely sure before I start replacing expensive parts that require a good deal of work to get done. There are a lot of defective New Brake Boosters from what I have been reading.

When you get a moment please fill out the profile on the Corvette Forum so we have an idea what you are working on. It saves you from a lot of the same questions and makes the system easier.

What part of Virginia are you in? Be sure to consider going to Corvettes@Carlisle on the third weekend in August every year. It is 105 miles from my home in NOVA and a very worthwhile place to go when you own a Corvette. The number of New parts for C4's seems to be shrinking but it is still fun to hang out with 50,000 Corvette Fans and roughly 10,000 Corvettes show up. I still find lots of stuff I need when I am up there. I have been going fairly regularly since 1991 when I bought my C3. I make a weekend out of it and spend Thursday thru Sunday there having fun spending money on my toys.

 

Thank you, and I took it for a small drive earlier today and I am pretty sure it's the brake booster now but I will check the hose before I look for buying a new booster. Thank you again!

 

I was lucky enough to be given a copy of the repair manual for my car from a neighbor actually so I thankfully have that in my possession. And I live in the Manassas area, but I would like to actually stop by there sometime that sounds like a lot of fun. Thank you so much!

 

Here in Virginia we have ZIP Products down outside of Richmond. If you order it early in the day, ZIP can have it to you the next day up here in Northern Virginia. I am sure there has to be a Guru of Brake Boosters out there who rebuilds them versus replacing them with cheap import knock offs. I looked at ZIP and they have your Brake Booster in Steel for $140. I would avoid the plastic ones.

When you buy the replacement be very careful and be sure they stand behind the part in case it is bad. The replacement parts coming from Asia are not of the best quality. Some folks on this Forum can tell you some horror stories regarding bad Brake boosters on the market. ZIP might be a good shot, their parts have been okay for me for a long time.

The repair manual you refer to, is it the Factory Service Manual or a Clymers type? The reason we make a big deal about the Factory Service Manual (FSM) is that it has troubleshooting charts that are not available in the aftermarket. The FSM has all the wiring information and schematics to show you what the mechanics had in the day. I apologize for making such a deal out of this but it is important. I tried buying a manual set for my daughter's Camaro and they wanted over $500 for it so I went the Fleabay route and bought a DVD. They put way more than just the FSM on the DVD, it was loaded with other valuable programs.

Check the vacuum your car is making as it is and post it. I would then go through it and cut the 1/2" off the end of every vacuum hose. I found one leak that was noisy off to the front left of the drivers seat and it was the Cruise Control System Vacuum line that had an effect on my idle.

Have you looked on You Tube? I looked and there is a video that might help you, there are actually a few it appears. Check out: "Brake booster on C4 Corvette" and you will find them. I watch them as I learn from others how they do it. It helps!