Hello All, I've got a 97' MN6 that i've only had a few months now. I've been noticing that the brake dust on the passenger/front rim is much worse than the drivers' side rim (front of course). Well, i had to stop aggressively yesterday and it seemes to pull in the passenger/front direction. Do these calipers (stock) have a tendancy to weaken/stick? I'm asking b/c if it could be something more serious their is no point just throwing money at a caliper...any feedback would be greatly appreciated.

 

How much are you willing to be a shade-tree mechanic like the rest of us?

If you are, then you can spend some time on checking things out and know what's going on, instead of getting some garbled, half-baked, answer from a mechanic.

The pulling tendency could be due to many things other than the brakes (road condition, tires, suspension, driver , etc). The extra dusting could be a symptom of something happening, so checking the brakes is a good first step.

HTH, and have a good one,
Mike

 

Do these calipers (stock) have a tendency to weaken/stick?

Sure they do.. GM and the infinite wisdom of their bean-counting offices decided America's premier sports car didn't need anything better that a sliding-type caliper.

What this means is you only have pistons on one side of the caliper. If the brakes on your car have never been serviced (properly, that is), the sliding pins are probably dry / grease used up.

Every time the pads are changed the pins should be cleaned and re-greased, using special high-temp grease. It's also possible that your pins may be pitted / worn if run w/o grease. You can inspect them when you do the re-grease procedure.

Let us know how it works out, and welcome to the Corvette brotherhood!

 

If your 97 calipers have had little or no service YES, they will give you serious problems. All is not lost!!!

The caliper should be able to move inward/outward (float) on the caliper mounting bracket. Yours is most likely frozen on the two pins that it moves/floats on. You will need to remove the caliper from the mounting bracket and clean and restore the special grease that the pins are lubricated with. You could also have stuck caliper pistons.

All you need to do is:

you will need:
-Two LARGE bottles of DOT4 brake fluid.
- Caliper grease (auto zone or Advance sells it Note## It must be CALIPER GREASE! regular grease will NOT work!!
-Two cans of spray brake parts cleaner.
- Red Lock tite thread locker.
-Small wire brush.
- New brake pads (your choice of brands)
-Anti Squeal compound for the backs of the prake pads.

Loosen the torque on the wheel/s that you are going to work on prior to jacking the car up.

Jack up the car and place it on jack stands. You can jack one wheel and do one brake at a time if you like.

Remove the wheel.

I use a large large pry bar and pry the caliper inward and outward to compress the pistons in the calipers so that there is clearance between the shoes and the rotor. Makes it easier to remove the caliper.

There will be two small fasteners that secure the calper to the brake claper bracket. Remove the two "SMALL" fasteners that secure the caliper to the pins. I believe that they are 13 mm (dont quote me on that one) DO NOT confuse the small caliper bolts with the LARGE bolts that hold the caliper mounting bracket to the spindle!
Once they are removed the caliper will be able to be slipped off of the rotor. NOTE** Do NOT hang the caliper so that it is putting tension on the hose.

Once the caliper is removed, you should be able to slip the rubber boot that seal the pins to the caliper off the caliper and pull the pins out of the caliper. You will most likely find that they are NASTY and will be very difficult to remove! Use WD-40 to help break down the rust/nasty grease.

Examine the rubber boots and make SURE that they are not torn or deteroriorated.

Clean out the wells that the pins slide into and clean the pins. Use the caliper pin grease and lube the pins and pin wells well. Shove the pins into the wells and force out any extra grease. wipe off extra grease. reinstall boots.

I use a C clamp and press against the old brake pad to force the caliper pistons all the way into the caliper. If the piston/pistons will not move that could also a cause of the caliper sticking.

NOTE check your brake fluid level in the master cylinder. When you force the pistons back into the caliper, the level in the master cylinder resiovour will increase and may leak out if it gets too full. The fluid will damage your paint if it spill on it!!!

Install the new brake shoes with the anti squeal compound on the backs of the shoes.

When I do a brake job, I suck out all of the fluid in the master, compress all of the slave pistions in the calipers, suck out all of the remaining fluid, add new fluid and bleed ALL of the calipers until new clean fluid comes out of each caliper. Make sure that you top off the master Cyl frequently!! You do not want to get air into the system!!!!

When I get home tonight, i will look up the torque specs for ya.

Hell,, If you lived close enough, I would do the brake job for you, or at least guide you through it!!

Bill

 

Wow, Thanks everyone, and Bill, thanks for the time to type all that out, I will wait until you post the torque specs and print everything out. I know the caliper is "free" (jacked it up and spun the tire, no problems) so I will give your advice a shot..I've done plenty of brakes. As for living close, I'm in Bucks County, PA so i'll spin my own wrenches ...thanks again.

 

Then you'll have no problems; it's the same setup as most domestic disc brake systems, with the exception of having two pistons per caliper instead of one.

I still don't think that stuck caliper pins can cause you to have a pull to one side. Uneven pad wear? Yes. You could also be seeing less dust on the side that's stuck (outer pad not working as hard) as well.

Let us know what happens, and have a good one,
Mike

 

I would not push the caliper piston in without pinching off the brake line with a proper hose pinching tool(not a vice grip!) and opening the bleeder and letting the fluid run out. Reversing the fluid(and sludge and contaminants) may break an internal ABS seal or master cylinder seal, which may cause major internal damage in the future.
Speaking of brake hose, it is possible one of the hoses may have collapsed internally (you wont be able to see it) and is blocked, causing the piston to push against the brake pad. To check for this, you can open a bleeder one at a time and see if any fluid runs out, and if it flows smoothly or slowly. Also, if you pump the pedal several times(with the bleeders tight!) and then open one bleeder, and the fluid squirts out feriously, the hose has collapsed. Hope this helps!

 

The Nuts,

I agree with cracking open the bleed valve and pushing the old fluid out rather than back into the system, but using some special (I've never heard of one) clamp on the hose (wouldn't that accelerate the very hose collapse you mention later?), just get the fluid collected in a container. The fluid will always follow the path of least resistance, and an open bleed valve is a LOT easier path than back up into the system.

As far as a collapsed hose goes, I've never heard of one on a C5. Also, the procedure you describe for testing for a collapsed hose will pass every time, since that's the same way you bleed the brakes!

Hate to say this, but you need to get your facts straight.

That said, have a good one,
Mike

 

NEVER pinch or kink a brake hose!!! That is the fastest way I know of to cause hose failure!!!

What ever way that you use, just make sure that you bleed the calipers and use DOT-4 fluid!

Opening the bleeded while pressing the pistions back in seems like a good plan.

Oh yea, YES stickey pins WILL cause the caliper to hang up and create excessive rotor heat, pulling and lots of excessive dust! You will have one pad looking like new and the other one worn down to nothing in no time flat!! Seen it a couple of times on C4's and once on a C5!

BC

 

My facts are straight, I been working on brakes for almost 13 years, and I've diagnosed collapsed hoses(it can happen to any car, I'm not saying that has happened to this car, just opening doors to find a solution) using this method, I may have not been clear enough or you misunderstood me. Yes pinching off the hose is acceptable by the Braking industry if you use the RIGHT TOOL, a rounded brake hose clamp found in special tool stores. Here's a site of one style-http://www.etoolcart.com/index.asp?PageAction=VIEWPROD&ProdID=346 6
If you do not use excessive force, not damage will come to the hose, thats the important part!
As for the bleeding, yes a normal stream of fluid is normal(gravity bleed), but a difference in flow from one side to another, or spitting out of fluid after 3-5 pumps on the pedal may indicate a problem in the path.

 

good luck!

 

Oh, BTW, if you didn't know this tool existed, I don't believe you should be working anywhere near an ABS equipped car.

 

Assuming you have the bleed valve open and the hose unclamped (the way us weenies Bill and I do it) when you compress the pistons, just how much fluid do you think is going to move backwards through the system?

Yeah, uh, sure, I'll keep that in mind.