Compressing Disc Brake Pistons

[Leesburg_Dave]

When replacing the brake pads on a 2004 Camry XLE (4 wheel disc brakes), do you need to rotate the piston while pushing it back into the cylinder or will just a large C-clamp work correctly? On my Mercury Sable (also four wheel disc brakes), the C-clamp worked fine on the front (used the old pad between C-Clamp and piston to protect the piston), but the rear pistons, because of the parking brake, required I use a tool to rotate the piston while pushing it back into the cylinder. I have not found any reference to needing to do that on the Camry rear disc brakes and in fact, one thread recommended against it. How do you deal with disc caliber/pistons that the parking brake operates? Thanks!

David

[BlackCamSe]

Originally Posted by Leesburg_Dave

When replacing the brake pads on a 2004 Camry XLE (4 wheel disc brakes), do you need to rotate the piston while pushing it back into the cylinder or will just a large C-clamp work correctly? On my Mercury Sable (also four wheel disc brakes), the C-clamp worked fine on the front (used the old pad between C-Clamp and piston to protect the piston), but the rear pistons, because of the parking brake, required I use a tool to rotate the piston while pushing it back into the cylinder. I have not found any reference to needing to do that on the Camry rear disc brakes and in fact, one thread recommended against it. How do you deal with disc caliber/pistons that the parking brake operates? Thanks!

David

the rear breaks on the camrys are a drum-in disk design. WHich means the parking brake is seperate from the brakes

[LE05]

^ which means you are fine to use a c-clamp to push in the piston on the rears. No turning required.

[Leesburg_Dave]

Thanks everyone, for your response. The "drum in disc" design comment was the revelation that caused it all to make sense. I was having difficulty understanding the diagram in my .pdf service manual because the parking brake section is different from the "brake" section and it looked like it applied only to drum brake models.

[judge34411]

Originally Posted by Leesburg_Dave

Thanks everyone, for your response. The "drum in disc" design comment was the revelation that caused it all to make sense. I was having difficulty understanding the diagram in my .pdf service manual because the parking brake section is different from the "brake" section and it looked like it applied only to drum brake models.

Just my 2 cents, but it is just one more reason why we should have drums at the back. 20% of your braking at the back.

Just think of it we have a disk and a drum at the back.

All this extra garbage just to have a handbrake work well. Because the disk handbrakes do diddly.

[JohnGD]

I actually prefer the drum-in-disc type. You actually have two independent brake systems back there. One operated by hydraulics and the other purely mechanical.

[fenixus]

i wish my car had drum in disc. old drum design look like shit, all rusted, pain to clean often. also you can see huge drums through stock alloy wheels which is not nice, unless you clean them periodically.

besides changing disc brake pads is like a spit in comparison to changing drum shoes and doing routine maintenance on drum components ...

just my 2 cents.

[judge34411]

Originally Posted by JohnGD

I actually prefer the drum-in-disc type. You actually have two independent brake systems back there. One operated by hydraulics and the other purely mechanical.

Yes, I guess your right it is built in redundancy which is always good.

My point was more about the need for disks in the rear.
An a cable for that hand brake would of been just fine to a drum.

[judge34411]

Originally Posted by fenixus

i wish my car had drum in disc. old drum design look like shit, all rusted, pain to clean often. also you can see huge drums through stock alloy wheels which is not nice, unless you clean them periodically.

besides changing disc brake pads is like a spit in comparison to changing drum shoes and doing routine maintenance on drum components ...

just my 2 cents.

as aesthetics go you are right

[fenixus]

what is the braking ratio (front : rear) for drum in disc anyways ? I guess it's lower than classic 80:20 (disc:drum).

[JohnGD]

I know what you mean. Those brake drums showing through the alloy wheels. What horrible sight!

Originally Posted by fenixus

i wish my car had drum in disc. old drum design look like shit, all rusted, pain to clean often. also you can see huge drums through stock alloy wheels which is not nice, unless you clean them periodically.

besides changing disc brake pads is like a spit in comparison to changing drum shoes and doing routine maintenance on drum components ...

just my 2 cents.

[JohnGD]

Front wheel drive is about 80%-20% front to rear.

Rear wheel drive is about 60%-40%.

So regardless of disc (drum-in-disc) or plain drum the rear needs to do about 20% for FWD.

Originally Posted by fenixus

what is the braking ratio (front : rear) for drum in disc anyways ? I guess it's lower than classic 80:20 (disc:drum).

[fenixus]

ah, i see, thanks JohnGD!

[judge34411]

Originally Posted by JohnGD

Front wheel drive is about 80%-20% front to rear.

Rear wheel drive is about 60%-40%.

So regardless of disc (drum-in-disc) or plain drum the rear needs to do about 20% for FWD.

yuppers right on. Just there to give a dragging effect and squat the butt of your car down.