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1993 Chevrolet Corvette - doesn’t stop like it used to after installing “premium” parts

…just saw this & wondered if anyone had some input. I replaced my front rotors & pads with “premium” parts and now my '93 stops almost as good as my old '53 pickup.

I would hope that it stops a lot better than an old truck.

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What did you see? I hope it accelerates better than the ‘53.

…well, yes. I would hope for that too, and yet…

Define “premium.” Especially the brand and model of the brake pads.

A lot of people put racing brake pads on their street car and then wonder why the thing stops so poorly. It’s because racing pads need to be heated to the kinds of temperatures you see on a real race track in order to hit their best performance, and they perform pretty terribly at normal street temperatures.

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He is saying his vette stops as well as his truck. New rotors are new rotors. Steel is steel. Or iron? So, I would say your pads are to blame. Either they are not good or they are bedded poorly. Does it stop evenly? No pulling? Front end dives as expected? Air in lines? New flex hoses? Bled properly?
I’d step back and say, was it stopping ok before? Usually you don’t wait till pads are grinding steel on steel. So I assume your old setup was ok?

Fifty three not 93 truck.

If you want good answers you must explain more fully. You have replied, unlike many that post vague “questions”… you didn’t actually ask a question… but the responses so far show the confusion.

Explain what was replaced with the brake job, who did it and what they said when you took it back… you DID take it back, right? If not, why not? What you are experiencing and why do you think it stops like a 53 truck. Hard pedal? What?

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Wow, i really didn’t expect any interest in my smart**s comment! But now that we’ve started…the corvette has always put a smile on my face, until i realized i needed to slow down for one reason or another. This was always the case with this car since i bought it in 2015, from Vermont (2K miles away), sight unseen, but a very good deal. So i learned to temper my enthusiasm while driving it, and reading-up on C-4 brake issues. I finally installed CENTRIC front rotors and HAWK street compound ferro-carbon pads. This combination was promoted for improved street performance. I did all the work myself and after break-in, they do stop the car marginally better than before. Braking from 40 to, say, 20 is adequate but when i stand on the brakes harder than in any other car i’ve ever owned, i can’t get lockup - even with anti-lock turned off (unplugged). I also changed the Vacuum Booster - no improvement. There’s a bolt in the mechanism connecting the brake pedal to the master cylinder that pushes directly on the master cylinder. I believe it’s purpose is to adjust free play in the pedal, and i adjusted it so there’s 1/2" free play at the pedal. I also bled the entire system as thoroughly as i could. It’s definitely a firm pedal, but no improved effect on stopping.
I’m thinking it’s some GM “engineering advance” in the ABS system gummed up after 28 years, and wish i could just disconnect the pump & sensors & computer, etc and revert to basics, like pedal to master cylinder to brake lines to calipers.
Wondering if any others have had similar conundrum?
And thanks for reading this, Cheers!

Sounds like you need a new booster. The ABS won’t really affect the ability to stop the car below lockup. It doesn’t “steal” pressure.

That combination of pad and rotor should put you through the windshield. It would on my 84 Corvette with inferior brakes to your '93.

Edit: After a bit more thought… what is the condition of your REAR brakes?? These cars use the rear brakes for much of the braking effort. Don’t discount them. They must be in good condition as well.

There is a tool to measure the pressure directly at the caliper. It replaces the bleeder and allows you to measure each corner to determine if you are getting the proper and equal pressure. If the brake fluid wasn’t changed regularly over the years, it is possible you have internal corrosion causing problems.

One last thing, replace ALL of the 28 year old rubber lines. I don’t care how they look, replace them.

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Have a shop that just does performance type brake work get this thing to work correctly . Sorry but I don’t agree with the wanting to return to the old 'simple ’ brakes.

Are you saying you have different brands of pads front vs rear? Like @Mustangman said, the rears are important, and in my opinion it’s important to match them front and rear on a car like a Corvette.

…sorry guys, i wasn’t clear. Yes, front & rear Centric Rotors & Hawk Pads, the rubber brake lines and the Power Brake Booster were also replaced. I’m liking the idea of the pressure testers at each caliper, who knows?

First thing I’d check…Did you blead the brakes?

Hawk make excellent pads. I suspect something basic here. I don’t think it’s the parts.

If you have the old parts…put them back on and see if it makes a difference.

You admit it stops better than previously. It appears you are a victim of inflated advertising claims. Apparently, the OE brakes were pretty darn good or perhaps the previous owner had already installed upgraded pads.

Your mention that you can’t lock the brakes w/o ABS on concerns me, especially because the car’s over 25 years old, with mostly 25 year old brake components.

You can try rebleeding the whole system again but if that doesn’t work, time to take it to a real mechanic.