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Disc brake caliper

revitup

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revitup Enthusiast

revitup

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Just finished replacing front rotors and pads on my '01 Silverado 1500. For the life of me I can't figure out how braking pressure is applied to the outside pad. The caliper appears to be fixed (unlike other 'floating' caliper systems I've seen) and the pads slide on pins in a bracket relative to the caliper. I can't see any way that the piston pushing on the inside pad will bring the outside pad in contact with the rotor. What am I missing?

Bish Senior Enthusiast

Bish

Posted
Posted

What Ken said. There are 2 pins the caliper rides on and they MUST be cleaned and lubed during a brake job IMO. When whell greased, when the brake is aplied, the caliper will center itself to equalize pressure on both pads. If the caliper hangs on the slides, you will get significantly more wear on one pad and not the other.

revitup Enthusiast

revitup

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How does the caliper center itself? It doesn't move as far as I can see. It's securely bolted with two bolts. The bracket holding the shoes slides. How does that put pressure on the outside pad?

C & A s Dad Senior Enthusiast

C & A s Dad

Posted
Posted
What Ken said.  There are 2 pins the caliper rides on and they MUST be cleaned and lubed during a brake job IMO.  When whell greased, when the brake is aplied, the caliper will center itself to equalize pressure on both pads.  If the caliper hangs on the slides, you will get significantly more wear on one pad and not the other.

 

 

 

 

Be sure if you do grease the caliper pins and slides, do so with a good syn grease specified for calipers. It comes in small tubes or small cans and can be bought at most all parts stores. Do not use regular dino or syn grease, it will not stay on there as long as John stayed in the army and it may get on your pads while it is running off.

Bish Senior Enthusiast

Bish

Posted
Posted
How does the caliper center itself? It doesn't move as far as I can see. It's securely bolted with two bolts. The bracket holding the shoes slides. How does that put pressure on the outside pad?

 

 

 

 

I'm assuming you have exactly the same brakes as my 01 Tahoe. If you remove the caliper bolts(2) and pull the caliper away from the rotor, you should be able to pull the caliper from the mounting bracket thus displaying the glide pins. If I recall, I had to remove the pads before I could seperate them. Look for the rubber boot and that is where the slide is. The boot seals the grease in and nasties out. They can stick or freeze resulting in uneven pad wear and reduced braking. Once you find them, clean them out and put good high temp grease in and make sure the caliper slides freely on the pins.

 

The function of the slides is to allow the caliper to float centering itself over the rotor. When it floats properly, equal pressure is applied to each pad resulting in full braking performance and equal pad wear. When floating, the piston pushes on the inner pad which pushes on the rotor which pushes on the outer pad which pushes on the back of the caliper thus giving you the squeezing of the rotor for stopping. If the caliper is stuck, depending on where, one pad will wear faster because it is not receiving equal pressure.

 

Sorry if you don't understand after that. That's the best explanation I can give you.

revitup Enthusiast

revitup

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"When floating, the piston pushes on the inner pad which pushes on the rotor which pushes on the outer pad..."

 

Sorry to be so stubborn but the rotor is fixed. There's no way that pushing on the rotor will make the rotor push on the outer pad. The caliper is also fixed. It doesn't slide on anything as far as I can tell. The only pins I see allow the pads and bracket that holds the pads to slide relative to the caliper. I still don't understand how that puts pressure on the outer pad.

Bish Senior Enthusiast

Bish

Posted
Posted
"When floating, the piston pushes on the inner pad which pushes on the rotor which pushes on the outer pad..."

 

Sorry to be so stubborn but the rotor is fixed. There's no way that pushing on the rotor will make the rotor push on the outer pad. The caliper is also fixed. It doesn't slide on anything as far as I can tell. The only pins I see allow the pads and bracket that holds the pads to slide relative to the caliper. I still don't understand how that puts pressure on the outer pad.

 

 

 

 

Take it apart and you will understand. Sorry I can't give you a better explanation. Because the rotor is somewhat fixed, the piston pushes on it and pushes back on the caliper(away from the rotor) which pulls the back side of the caliper towards the rotor.

 

Trust me, take it apart and you will understand. If after disassembly, you still don't understand, I think you should leave the brakes to somebody that understands for your own safety.

 

Another way to think about it is to compare it to a C clamp. When you clamp something, you are pushing on one side only yet the presure is equal on both. Same with a caliper except it has to be able to slide as the pads and rotor wear thus the slides.

revitup Enthusiast

revitup

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I've had it apart, changed pads and rotors and put it back together. I appreciate the concern for my safety but I have done dozens of brake jobs over my lifetime both disc and drum. I understand how every other brake system I've seen works. I'm just looking for a comprehensible technical explanation of how this particular system works. If that information isn't available here that's OK. I WILL pursue this until I get an answer. When I do I'll post it here for anyone who's interested. Thanks for the replies.

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