PDA

View Full Version : ever had this happen to your vehicle brakes?


milkmania
03-07-2006, 11:34 PM
Wagner Thermo Quiet six months old

poor lighting & pic....I'll get a better pic tomorrow

SKI*MC
03-07-2006, 11:36 PM
wow! Maybe thermal expation and contraction?

milkmania
03-07-2006, 11:42 PM
wow! Maybe thermal expation and contraction?

dunno, I had a very notable tire shop do all the brakes 6 months ago....
turn rotors....etc...

Went on a trip to Tulsa and almost killed my family by narrowly missing an accident, because the rear drums were not adjusted out properlt creating a lot of extra force on the disks... less that 1 week, had it back to adjust drum's pads out.

Still didn't feel "right"
Went for about a month, the I ran the drum's pad's out myself! felt better

took it into a different shop yesterday because of steering wheel vibration under braking... the mechanic said the rotors needed turned. I said do it.

He said while the rotors were turning, he got bored and checked the pads for glazing and found this!

the thing is, when some of these do a brake instection, they look at the thickness of the pads without pulling the calipers off....had it not been for warped rotors, we wouldn't have found these cracks.

Leroy
03-07-2006, 11:51 PM
Had to read up on them. Those are some brakes.


http://www.benzworld.org/forums/forums/thread-view.asp?tid=1235692

.

Leroy
03-07-2006, 11:53 PM
Milk are the cracks bad? I mean is this a bad thing?

milkmania
03-08-2006, 12:05 AM
Milk are the cracks bad? I mean is this a bad thing?

some of the cracks are completely through the material to the steel plate....

I can't see how that would be a good thing... I'm not happy with them:(

PendO
03-08-2006, 12:30 AM
not that it matters now, but I was suprised last time I needed rotors turned, new rotors were not much more ... if they keep warping that fast I would try new rotors next time ... as for the cracking and the warping, I have never seen pad's crack like that with all the thickness left ... wonder if it is a 'what came first - chicken or egg' thing ... when the rotors got turned the first time was that the first time?

PendO
03-08-2006, 12:35 AM
here is a good post from leroy's link:

Author Posted 11/21/2005 5:25 PM (#1674736 - in reply to #1674366)

rudeney


RE: Brake Nightmare!

I have used this method and it works very well. This information on this website is all very good and accurate. One thing to remember when changing brakes, if you don’t change the pads and rotors together, then you have some extra work to do. Even high-quality, well-maintained brakes will create wear grooves in the pads and rotors. This is inevitable with today’s semi-metallic pads, and especially true with OEM pads that use a softer graphite-based pad stock.

Basically, if you put new pads on a used rotor, two bad things will happen. First of all, the new pads will have only partial contact with the rotor surface because of the existing grooves. With use, they eventually “break-in” and match, but during that time, you will have a second problem, which is the generation of extra heat. Since the used rotor will have a highly polished surface, this will reflect heat back into the pads. Overheated pads can cause all sorts of problems like breaking down the material used to bond them to the metal backers, and crystallization of the base material used in the pads. Crystallization will cause the pads to be harder, which will cause squealing when they contact the rotors and reduced braking ability.

The best case is to always mate fresh pads to a fresh rotor surface. Replace the rotors and pads will accomplish this, but if you re-use existing rotors, you need to prepare the surface. One way to do this is to have the rotors machined or “turned”. The problem is that most rotors will be near or even beyond minimum thickness spec after running through just one set of pads and they cannot be turned. If they are still within spec, you can just “knock down” the rotors. This is a process where you roughen the surface with sandpaper. The goal is not really to attempt to flatten the surface (as machining would do), but simply to knock down the highest ridges and remove the shine. This will allow the new pads to seat better.

Of course if there are any really deep gouges in the rotors, or if they are warped (as evidenced by vibration during braking), then they should be replaced. Also, if you see any dark spots on the rotors, that is a sign of a bad caliper, in which case all calipers and rotors on the axle must be replaced. It’s also a good idea to replace your brake fluid with every other pad change. Brake fluid that has been heated is less effective. In a worst-case scenario, it can easily cost over $1,000 to DIY, but the best car in the world is no good if you can’t stop it!


********************************
Milk, I bet they didn't turn your rotors good the first time, and I wonder now if there is enought thickness left for heat dissipation.

Leroy
03-08-2006, 12:37 AM
Overall there was a lot of happy people with these brake pads, with a few exceptions when people did half-a$$ repairs.

PendO
03-08-2006, 12:45 AM
Overall there was a lot of happy people with these brake pads, with a few exceptions when people did half-a$$ repairs.

true dat ... and shops like the labor for turning the rotors (helps pay for their machine) rather than sublet for the parts and only getting a small markup IMO.

88 PS190
03-08-2006, 12:57 AM
Don't know what sort of vehicle this was on, but i've seen cracks in pads resulting from recent upgrades such as adding +sized wheels, or adding HP. It generally means your brakes are being overworked.

Could be that you are towing a boat, and should upgrade, also when you arrive at the lake alot of people are hyped about dumping the trailer in to go boating, but you should allow the brakes to cool down a bit first so the change in temp isn't so drastic. That's just my take on this part.

PendO
03-08-2006, 12:59 AM
Don't know what sort of vehicle this was on, but i've seen cracks in pads resulting from recent upgrades such as adding +sized wheels, or adding HP. It generally means your brakes are being overworked.

Could be that you are towing a boat, and should upgrade, also when you arrive at the lake alot of people are hyped about dumping the trailer in to go boating, but you should allow the brakes to cool down a bit first so the change in temp isn't so drastic. That's just my take on this part.

I hope he keeps the front rotors/pads dry when backin' in the trailer:) But the other stuff makes sense!

erkoehler
03-08-2006, 01:01 AM
I hope he keeps the front rotors/pads dry when backin' in the trailer:) But the other stuff makes sense!


The ramp on the river here doesn't even require any wheels to get wet.

milkmania
03-08-2006, 09:56 AM
Don't know what sort of vehicle this was on, but i've seen cracks in pads resulting from recent upgrades such as adding +sized wheels, or adding HP. It generally means your brakes are being overworked.

Could be that you are towing a boat, and should upgrade, also when you arrive at the lake alot of people are hyped about dumping the trailer in to go boating, but you should allow the brakes to cool down a bit first so the change in temp isn't so drastic. That's just my take on this part.

These brakes are on a 1997 K1500 Suburban (wife's). We did travel with pulling the boat a small portion of last season, but very limited amount... there was only one trip where we pulled the boat with this suburban. The other times we pulled the boat with my K2500 Suburban (3/4 ton).

Those pads have less than 20,000 miles on them also. My son picked the wife's truck up last night, and I got a chance to drive it this morning.... completely different truck! brakes pedal feel is solid, steering vibration is gone. I know that's typical with a rotor turn also, but the last time they didn't ever feel like they do now.

Just checked the website for the first place that did my initial brake work...
Been in business since 1963, I've used them off & on since 1987.
8 service bays, and 3 alignment bays.
They had an awesome front end mechanic for years, but now retired.
I'm the kind of guy that's got to be in the bay with my truck, and they've never had a problem with that.

I'll check with them at least to see if the pads are warrantied, or I'll probably just suck it up to experience.

We'll see, since I replaced them with Thermal Quiets again.

milkmania
03-08-2006, 09:59 AM
I hope he keeps the front rotors/pads dry when backin' in the trailer:) But the other stuff makes sense!

the wife backs me in on the ramp, and when the front bumper touches water, she knows she backed in far enough ;)






not truehttp://deephousepage.com/smilies/lol.gif

Workin' 4 Toys
03-08-2006, 12:58 PM
the wife backs me in on the ramp, and when the front bumper touches water, she knows she backed in far enough ;)






not truehttp://deephousepage.com/smilies/lol.gifMine too, but of course thats because I have a hitch on the front of the truck too.....:D