Been working thru braking problems with my 1994 C4 Coupe, have posted issues in other threads but decided to start a new one here.

The brakes are terrible until the pads get heated up. When I first take off for a drive (cold) there is poor to very little braking even at low speeds. (dangerous) If I run the car up to about 40 mph keeping the gas pedal in the same position, then apply the brakes hard dragging the brakes for about 1/8 mile or more till the car pulls down to about 30 mph, the brakes start working great. Brakes will continue to work great until the next day when everything is cold and I'm back with little to no braking until I run it thru heating the pads. If I go out for a normal drive the brakes will never heat up.

The pads are new but I can't remember where or what brand I purchased a few years back. Never heard of having to heat up the pads to get them to work. Any ideas here and what would be a good set of brake pads for replacements????

 

did you burmish them in? most new brakes now days require you to do a few 40 mph hard stops to get the brakes good and hot.

readin again, ya.. you might have some issues brakes hoses maybe swelled up and not flowing good amounts of fluid? all sorts of things could be wrong

 

Can you activate ABS? If not, can you hear it self test on start up? It should sound like a growl coming from behind your seat, the ABS module is in the storage compartment behind the driver seat. Any trouble codes?

If you got racing pads it wouldn't be unusual for them to not brake well until you got some heat in them, but I'm sure you would remember buying a set of those, they hurt the wallet much more than part store pads. Most parts stores don't sell those pads anyway, since they would be unsafe for public roads.

About 2 months ago I refreshed my brake system, I'll list what was done and what I noticed.

Fresh Fluid and new master cylinder (old one didn't send fluid to the rear):
Decreased brake distance considerably when pads were warm, still didn't have good stopping power until pads were warmed up

Brake Booster changed:
Easier stopping effort, still didn't have good stopping power while cold.

New pads (Carbotech AX6) and rotors:
Finally got the stopping power I wanted when cold, stops hard enough to slam people into the dashboard if they don't have a seatbelt on (wear your seatbelt!). Can finally activate ABS at will.

SS Hoses, old ones were about 2-3 years old:
Less variation in pedal feel when brakes are warm. Braking wasn't any better than with rubber hoses, just felt more consistant in the pedal. Make sure whatever hose you use are DOT approved!

I'd try flushing fluid and changing the brake hoses in your car. 27 years is a long time for rubber, some new hoses and fluid might help considerably, and in the process you might notice other issues. When I bled my brakes I realized I had no fluid to the rear.
After that I would try pads and rotors. If they have enough material you might be able to get away with having the current rotors turned, but for the price of new ones online you might as well just replace them.

Remember, in the 80s/90s this was a very high performance car in all aspects, including brakes. They were incredible for the time, and are more than adequate today, especially with the new tire technology and incredible brake materials we have available today. Besides the ABS, there's nothing complicated about this braking system, and the ABS tends to be trouble free.

 

To me it sounds like the OP probably put in full ceramic pad. Many put them in because of the lack of brake dust but came to regret it. The driving characteristics of ceramics I've read sound much like the OP listed. Personally I would check them out and if they are full ceramic, I'd at least swap them out for semi-ceramics.
Good luck.

 

I think I've owned this car for over 25 years. From the beginning I always thought the brakes should be much better. Multiple rotor and pad changes over the years with no difference in braking performance. (218,000 miles) My memory is poor these days, just got back from Autozone to check the purchase history for this car. Appears I didn't purchase the pads from them so I must have ordered them online somewhere.

Had issues with car from sitting and the brake lines rusted out. Replaced all the lines and pads (guessing) three/four years ago. Braking was terrible as described above post and I blamed it on several things, mainly bleeding the brakes. The rotors rusted up quite a bit from all the sitting and it wasn't until I was dragging the brakes to clean them up that I noticed braking was improving some. It wasn't until I lost my temper and drove down the road with foot on the gas and on the brake as hard as I could that brakes became great. ABS for the first time ever would operate on dry blacktop. Never before would the ABS operate on blacktop,,,,,, gravel and snow yes. I think I'm down to the pads being the issue, just haven't ever heard of pads needing heated up before they would work.

I remember wanting to try Hawk pads, do Hawk pads need heated up?????? I love the braking power on the car now but it would be dangerous for anyone else to drive this car. Would love to get this braking performance with a pad that does not need heated up.

Open for pad suggestions.

 

It depends on the pad you chose. Hawk has street, autocross, and track pads. Could you try and track down what you ordered in your email?

Another overlooked issue would be you changed pad types without changing/turning rotors. If the previous brake pad material that was left on the rotor isn't compatible with the new brake pad material, friction is adversely affected. Change the rotors or take them somewhere and have them turned if they have enough material, it might make a big difference.

Just a rough overview of pads:

Pad types
Street pads: Effective from ambient temperatures to 600-800 degrees F. Typically low noise/low dust ceramic, or potentially an organic from the factory, but these are becoming rare.
Autocross pads: Effective from 50-1000ish degrees F. Generate noise and dust if not hot
Racing pads: Effective from 400-1600+ degrees F. Generally unsafe until heated up, will generate noise and dust

I wouldn't go beyond the autocross pads unless you intend on tracking the car. They are loud and require heat for effective braking. A good set of ceramic brake pads should be able to engage ABS on a dry road surface.

We have a Carbotech vendor on the forum, Adam with Amped Autosports. I have the AX6 (Autocross pads) purchased from him on my Corvette and love them, even with the noise and dust.
On my Mustang I have G-Loc GS-1 (Street pads, comparable to Carbotech 1521 pads, might even be identical). They have no issues triggering ABS, and are much quieter than the AX6 pads.
Plenty of people choose Hawk pads, they get plenty of love on forums. I haven't tried them so I won't offer an opinion.
Powerstop by Centric pads are also an option. I personally hate the feel of them, but they do lock up the tires on my dad's Camaro repeatedly. Just have to press harder than I'd like to.
EBC makes garbage in my opinion. I've melted 2 sets (yellow and redstuff) of their pads on my Mustang, and I've had their pads start losing chunks very early on a Suzuki VS800, a fairly light cruiser. Some people swear by them, I absolutely do not.

There are other excellent brands I can't think of, and plenty of pads on the market to find what you love.

I will say this, Carbotech/G-Loc (They are different companies) pads are more expensive than most pads. Their biggest selling points are Made in USA, very rotor friendly, non-corrosive dust, and the ability to change pads without changing rotors. If you tracked, this would be a huge benefit since you could switch from a street 1521(Carbotech)/GS-1(G-Loc) to a XP12(Carbotech)/R12(G-Loc) without adversely affecting braking on the street or track. You should also be able to switch between the two brands if you find a better deal on one over the other.

Do some research on the pads they have available, and make sure to have your rotors turned or replaced whether you get new pads or not. It might make a huge difference in what you currently have.

 

Wow......What a hard learning experience. I would have never thought a brake pad produced for the public, racing or not, would not provide stopping power until heated up. I always thought manufactures worked on pads that would not fade when hot, didn't know that would come with a trade off when cold. I don't know if I should be impressed or be bent out of shape. Go figure.

I need a new set of pads for sure. Took the Vette out tonight and heated up the brakes, then locked the tires a couple times activating the ABS. Then continued on a nice cruise driving normal for several miles on the interstate. Guess what, the freaking pads cooled down enough to go back to the poor braking. Ran thru the pad heat up and brake stopping power returned.

 

It sounds like someone put race pads on a street car.

 

This is exactly what I thought when I read the original post. Dan

 

For a high quality low dust performance street brake pad take a look at the Carbotech 1521 brake pad 100% non-corrosive dust will not harm your wheels, paint or rotors. Carbotech brake pads are 100% made in the USA and contain NRS Technology Here is a link to explain further what NRS technology is exactly: http://www.nrsbrakes.com


Carbotech brake pads can be ordered by calling me at 216-780-8825 Or order direct Here Ampd Autosport | One of the Largest Internet Retailer of Carbotech Per – Amp'd Autosport Use promo code z28 at check out for your forum discount.



The Carbotech Bobcat 1521™ is our high performance street compound that is our most successful compound. The Bobcat compound is known for its awesome release and modulation, along with unmatched rotor friendliness. Like our AX™ & XP™ line of compounds, Bobcat 1521™ is a Ceramic based friction material offering minimal rotor damage and non-corrosive dust. Bobcat 1521™ offers outstanding performance, even when cold, low dusting and low noise with an excellent initial bite. This compound’s virtually perfect linear torque production provides incredible braking force without ABS intervention. Bobcat 1521™ operating range starts out at ambient and goes up to 900°F. Bobcat 1521™ is suitable for ALL street cars, perfect for your tow vehicle, police cruiser. The Bobcat 1521™ compound has been found to last two-three times longer than OE pads you can purchase at a dealership or national retailer. That’s one of the beauties of Carbotech Ceramic brake compounds. Bobcat 1521™ is NOT recommended for any track use.
__________________
Adam Adelstein
Amp’D Autosport.com
Internet's largest retailer of Carbotech Performance Brake Pads.
PH:216-780-8825.
Email: sales@ampdautosport.com
Web Site & Direct ordering http://ampdautosport.com/
All major CC and Pay Pal accepted.
Check out Promo code:z28

 

I’ve got an 87- non ABS, street cruiser only,
18” rotors, 96 calipers-2 piston
The brakes-all new everything,
plus ss lines, wildwood proportioning valve
I installed duralast gold-
lifetime warranty, 0 brake dust
probalbly have at least 75k on them- work good last long time👍
they were around 42$ ish
initially they didn’t feel quite as responsive- as hawks, after 10 mts u adjust

with the wildwood proportioning valve this combo will get u there n back, no warmup required
its by far the best system on this car👍

the only time I’m cautious with this brakes setup is surface rust on rotors for the first brake application ie car wash

😎🇺🇸

 

I put C5 calipers and rotors on my 86. I could hardly tell the difference.
i went to NAPA and talked to the counter man, and he recommended the NAPA performance pads.
I know nothing about them, except after I put them on, i had twice the brake performance. The pads i took off were from a wrecked 2002 C5.
Now i know why it got wrecked.
it wouldn’t stop very good.🤪

 

It sounds like pads to me too.

I had an '88 that had the same symptoms. Very poor braking when cold and also when wet.

I don't know what pads they were (installed by previous owner and I suspect race pads), but a pad change fixed my braking problems.

Good luck.

 

Change pad compounds

 

if there racing pads ,there design to work at hot temps. they have to be warmed up to work. I use hawk hps

 

..... Your booster might be shot ! .....

 

Already replaced the booster.

I believe I did put Hawk race pads on a couples years ago when I replaced all the brake lines. Now I need the best stopping power from a street pad.

 

The Carbotech AX6 pads are the best stopping street pad. They are designed for Auto X they stop from dead cold. Yes they are going to make some noise and dust but if you care about stopping these are what you want. The 1521 is a low dust street pad it does not have the braking force of the AX6.

CARBOTECH™ AX6™

The AX6™ is specifically engineered for Autocross applications. A high torque brake compound delivering reliable and consistent performance over a very wide operating temperature range of 50°F to 1000°F + (10°C to 537°C+). The advanced compound matrix provides an excellent initial bite, high coefficient of friction at lower temperatures along with very progressive brake modulation and release characteristics. Many drivers use the AX6™ for street driving as well, even though Carbotech™ doesn’t recommend street driving with AX6™ due to possible elevated levels of dust and noise. AX6™ is NOT recommended as a race compound in most applications.

Order here Chevrolet Brake Pads – Amp'd Autosport (ampdautosport.com)

Adam Adelstein
Amp’D Autosport.com
Internet's largest retailer of Carbotech Performance Brake Pads.
PH:216-780-8825.
Email: sales@ampdautosport.com
Web Site & Direct ordering http://ampdautosport.com/
All major CC and Pay Pal accepted.
Check out Promo code:z28

 

When you changed the booster, did you by any chance adjust the rod to it?
Not that this will play much into your situation, but it can affect how your pedal feels too.
I think you did get race pads. I use Hawk HPS, and when they warm up, doesnt take long, they rock.. Lot of dust. But they will activate ABS at over 100mph. Even with sticky tires.