I am new to this forum and to Corvettes. I have a 1991 L98 with the Z07 suspension option.

Car is pulling to the right when braking and I also noticed the rotors have seen better days.

Am looking for any suggestions on upgrading rotors and calipers (and anything else in the system I should consider). Not looking to break the bank, but just ensure good stopping.

Also, I assume I have ABS and was wondering the proper method to bleed the system when I make these changes.

Thanx,

Scott

 

Lets start with the famous trio. Pads, Rotors, Hose. Depending on how handy you are, you can DIY or send it off. Pretty simple job. I would get Goodridge SS braded hoses



Goodridge

Brakes and Rotors

 

Yes there is a specific procedure and a '91 is the last year before ASR, the procedure is different from any later year. Do you have the FSM? You want to follow the FSM procedure for the "year specific" from the FSM.

Quality parts from most any local vendor will give you satisfactory braking. I don't believe that an Internet purchase should be required. I'm sure there's a bit of research involved and you've not mentioned your location so it's certainly not something that I or anyone else can just say "do this". Quality parts from a known vendor, a "toe to toe" purchase would maybe be the desired.

If your '91 has a complete Z07 package it would have 13" rotors and they're "directional/side specific", as long as that's kept in mind you should be all set. SS/braided lines certainly could be an upgrade to consider but off the shelf replacement hoses might be a more practical buy. I'd think maybe not but depending on your location and what's available I might consider "off the shelf" stuff.

 

I am located in Orlando and I do not have a FSM. I guess I can find one online.

Thanx for the feedback and any other advice you would have.

 

I would second that the ss brake lines would be a good addition. If you think the calipers are stock, it may not be a bad idea to replace them with new as well. Search around and you can get these calipers pretty cheap. As far as rotors, maybe get some slotted rotors. For pads, these are what are important to help you stop better, look at Hawk HPS Street pads.

When bleeding/flushing the system, the best way is gravity bleeding. This takes a little longer, but gets all the old fluid out and aeration out. Raise the car up on four jack stands and remove the wheels, which you will need to do this to replace your rotors and calipers and brakeline any way. You have two reservoirs on your master cylinder for the 91. The rear one is the fluid for the rear brakes and the forward is for the front brakes. Pull the caps off the reservoirs and suck out all the old fluid with a turkey baster and then fill with fresh fluid. The use of DOT 4 synthetic is good for street driving. Once you have fresh fluid in the reservoir, go to the brake caliper furthest from the reservoir and open your bleeder screw until fluid starts to come out. I and most people will place a hose on the bleeder screw that will drain into a container that you can later pour out and dispose of old fluid. Let this keep draining until you see the fresh clean fluid. Also keep and eye on the reservoir and don't let it empty. Once you have clean fluid and no air bubbles you can close the bleeder screw and move to the opposite side. Repeat until all four calipers have been bled. This will take up to 1.5hrs to do, especially if the system hasn't been changed in a while. But it is worth the time.

 

For '91 MY if you're going to "BLEED ALL" the proper sequence is RF, RR, LR & LF - all distribution is done from the ABS module so the procedure mentioned above using what "seems to be" the furthest and maybe logical choice isn't the correct choice. Does it matter? I'd say so.

That's why I suggested and mentioned the FSM. Sooner or later the FSM can certainly help you and you might just keep an eye out for one to buy when it's convenient. Do the basics first, remove the wheels and make sure the caliper hardware is in good condition and all present. There's pins and e-clips on the fronts and it's not unusual to find them missing, incorrectly installed or whatever.

 

Hi

Pulling to one side is usually the calliper sticking/ brake hose swollen and collapsing inside or uneven brake pad wear.

As others have mentioned replace the brake hoses, flush the brake fluid with dot 4 brake fluid.
I usually gravity bleed my brakes, pumping the pedal usally ruins the booster daprhagm from experience.

You can replace the rotors and get some high metal content brake pads to reduce pedal effort and give better stopping power.
Hawk street pads are a good comprimise for road cars.

See the rotors i have on my vette, they are quite cheap and look great.

ebay listing, see link below.
http://www.ebay.com/itm/FRONT-REAR-SET-DRILLED-SLOTTED-PERFORMANCE-BRAKE-ROTORS-ATL022762-/281295312570?pt=Motors_Car_Truck_Parts_Accessories&hash=item417e81d6ba

 

Fluid flush new rotors like Centric and Carbotech 1521 pads and some SS lines such as goodridge and you should be good to go.

Carbotech™ Bobcat 1521™ 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.

 

I drive a mix of conservative and aggressive and the stock rotors and pads lasted over 50k miles. This climate is dry so fluid discoloration from water adsorption is low, but often checke, along woth the other fluids.

Remember, that harder pads will erode the rotors faster. I am evaluating the performance of ceramic pads on two other cars, right now. There was a small price increase over standard pads but I see no real gain either, to my professional mechanic pal said they perform better and wear rotors less. Not sure i agree with him.

I did not like the result of slotted rotors until I had them machined down to near-no slots! Hardy required for the street anyway and I have no need to gab about pricier mods that serve no purpose for my driving.

You mentioned the 'bank', so while others may not care, I am not into spending dough for bragging rights. The performance of any newish Vette is far beyond what most of us will ever use, but obviously, each to his own.
I prefer to spend where it delivers what I can use (incl. FSMs).

 

I will piece the information together and start looking for parts.

The gravity feed bleeding is interesting. Never done that.

Adding all of this should be fun...just hope I get it right.

Thanx.

 

The gain I have seen is when you have repeated braking in the summer, the fade seems less with the more expensive stuff.

 

Here's for comparison, when I bought the 86 last year the brakes had already been upgraded to SS hoses, drilled and slotted rotors and ceramic pads. Being they were already on the car and it came from a car auction, I have no idea who made them or when installed.

One thing I have noticed is the brakes take more pressure when cold and seems to take a little more distance to stop. Once I've gone a little ways they warm up then if you hit the brakes it stops you right now.

I have no idea how long they've been on the car and as I've only driven it about 2K miles since purchasing it, it's early to say how they'll work over the long haul. The brake fluid looked fairly fresh when I bought it so it's unchanged at this time.

Just informational in case it's of use.

 

People talk about this all the time. I find vacuum bleeding to be much much faster. The premise is the same-draw fluid through the system until you see clean fluid at the wheel. With the vacuum bleeder it's five minutes a wheel. An indispensable tool in my box.

 

I have seen pressure bleeding. Pressurized can with cake fluid and it hooks up to the reservoir. Open bleeder till it runs clear, repeat 3 times more and you are done. Vacuum makes me wonder if there is any air that got past the thread of the screw

 

I looked at the Service Parts Identification Code decal in my center console and I see a code J55. I assume that is the brakes.

Is that indicative of 13 inch rotors?

P.S. Factory Service Manuals are on the way.

Scott

 

I found a breakdown of my codes, then researched and found that J55s are 13".

 

Yes you have the J55 13 inch rotors and J55 callipers.
All you need for great brakes is hawk street brake pads, and fresh dot 4 brake fluid.
You will be suprised how good the brakes can be, when using the right brake pads.

The Hawk hp plus for track use , however they are a bit noisy and too dusty for street use. However the hawk hp plus can take lap after lap after lap, wirh no brake fadevjust awsome stopping power.

 

Since the front and rear brake circuits are completely isolated from each other, couldn't you do RF, LF, RR, LR?

 

Regarding bleeding the brakes, I have used the Motive Power Bleeder for years. $65 for the 0108.. hooks right up. Stupid simple. I can't lend it out cuz I'll never get it back

 

The 0108 DOES NOT WORK ON mid-to Late 80's C4's. I bought one last week based upon this thread only to realize it doesn't fit. I am still trying to find the correct top for the 80's era C4.