1991 ZR-1 Brakes soft peddle -- cure or upgrades available? - ZR-1 Net Registry Forums

ggarrettson · 06-08-2004

Since I bought the car new, the brakes have always had a slightly soft peddle. Under hard braking such as encountered on a track, it becomes very noticeable. It requires one pump before braking to achieve satisfactory performance. I use Motule high temperature brake fluid and Performance Friction Carbon Metallic pads. I've replaced the pads and rotors, rebuilt the front calipers and thoroughly bled the system many times, without solving the problem. Is there another procedure or upgrade I can use to solve this problem?

At the track another enthusiast said he had heard that C5 calipers could be fitted to the ZR-1. Is there any truth to that? If so, would that be advisable?

WB9MCW · 06-11-2004

I THINK IT IS TIME FOR A NEW MASTER BRAKE CYLINDER.. MY 84 HAD SOFT PEDAL AND WAS FIXED BY REPLACEMENT. SEE THIS UPGRADE TO 96 GRAND SPORT CALIPERS BUT IT IS BIG $$ Although equipped with air cooled 13 inch rotors, the ZR1's brakes leave a lot to be desired. With just a few harsh applications from higher speeds, the brakes begin to fade and rumble. The most popular street upgrades include changing to an after-market reinforced factory caliper or simply purchasing the 1996 Corvette front brake caliper available on the Grand Sport models. These factory calipers are not only stronger than those originally installed on the ZR1, but they look terrific especially through the 5 spoke wheels. Also recommended are the replacement of the rubber hose brake lines to those of stainless braided steel. When refilling and bleeding the brake system, the use of a high performance brake fluid (i.e., Castrol SRF) can also help achieve positive results.

High performance brake pads are readily available in a variety of compounds. Basically, the better the pads work, the dirtier and noisier they are. That is, the harder compounds make more noise when applied and produce much more brake dust which tends to coat the wheel. Also, the harder pads will wear the rotors significantly faster than stock pads.

For the more track oriented enthusiasts there are a number of complete brake packages available all the way up to full competition packages. These packages range from $2,500 to $6,000 and vary greatly depending on manufacturer. In some cases, the front steering knuckles must be modified to accommodate the larger calipers, only selected wheels will clear the calipers, and certain rear brake upgrades require the parking brake be removed. Others, have a custom park brake package available for a mere $750. If you are going to drive aggressively, you'll certainly need a brake upgrade.

Companies that offer Brake packages:

Callaway (860) 434-9002
Doug Rippie Motor Sports (612) 559-7605
Lingenfelter
Corvette Consultant (516) 668-5780
mov'it :!:

06-08-2004	#1
ggarrettson Join Date: Jun 2004 Posts: 1	1991 ZR-1 Brakes soft peddle -- cure or upgrades available? Since I bought the car new, the brakes have always had a slightly soft peddle. Under hard braking such as encountered on a track, it becomes very noticeable. It requires one pump before braking to achieve satisfactory performance. I use Motule high temperature brake fluid and Performance Friction Carbon Metallic pads. I've replaced the pads and rotors, rebuilt the front calipers and thoroughly bled the system many times, without solving the problem. Is there another procedure or upgrade I can use to solve this problem? At the track another enthusiast said he had heard that C5 calipers could be fitted to the ZR-1. Is there any truth to that? If so, would that be advisable? __________________ G2

06-11-2004	#2
WB9MCW Join Date: Dec 2003 Location: McHenry, Il. Posts: 6,607	I THINK IT IS TIME FOR A NEW MASTER BRAKE CYLINDER.. MY 84 HAD SOFT PEDAL AND WAS FIXED BY REPLACEMENT. SEE THIS UPGRADE TO 96 GRAND SPORT CALIPERS BUT IT IS BIG $$ Although equipped with air cooled 13 inch rotors, the ZR1's brakes leave a lot to be desired. With just a few harsh applications from higher speeds, the brakes begin to fade and rumble. The most popular street upgrades include changing to an after-market reinforced factory caliper or simply purchasing the 1996 Corvette front brake caliper available on the Grand Sport models. These factory calipers are not only stronger than those originally installed on the ZR1, but they look terrific especially through the 5 spoke wheels. Also recommended are the replacement of the rubber hose brake lines to those of stainless braided steel. When refilling and bleeding the brake system, the use of a high performance brake fluid (i.e., Castrol SRF) can also help achieve positive results. High performance brake pads are readily available in a variety of compounds. Basically, the better the pads work, the dirtier and noisier they are. That is, the harder compounds make more noise when applied and produce much more brake dust which tends to coat the wheel. Also, the harder pads will wear the rotors significantly faster than stock pads. For the more track oriented enthusiasts there are a number of complete brake packages available all the way up to full competition packages. These packages range from $2,500 to $6,000 and vary greatly depending on manufacturer. In some cases, the front steering knuckles must be modified to accommodate the larger calipers, only selected wheels will clear the calipers, and certain rear brake upgrades require the parking brake be removed. Others, have a custom park brake package available for a mere $750. If you are going to drive aggressively, you'll certainly need a brake upgrade. Companies that offer Brake packages: Callaway (860) 434-9002 Doug Rippie Motor Sports (612) 559-7605 Lingenfelter Corvette Consultant (516) 668-5780 mov'it :!: __________________ http://i119.photobucket.com/albums/o...9mcw/SIG-2.jpg http://i119.photobucket.com/albums/o128/wb9mcw/vcm.gif "The Budget should be balanced, the Treasury should be refilled, public debt should be reduced, the arrogance of officialdom should be tempered and controlled, and the assistance to foreign lands should be curtailed, lest Rome will become bankrupt. People must again learn to work instead of living on public assistance." - Cicero, 55 BC " We the people are the rightful masters of both Congress and the courts, not to overthrow the Constitution but to overthrow the men who pervert the Constitution." - Abraham Lincoln