Rear brake calipers used for the front?

Are calipers just calipers? Can I use rear calipers from a car on the front of a car?

Example being rear brembo 4 piston calipers on the front wheels of a car?

Andrew

There's no inherent reason you shouldn't, but on top of rear brakes usually having small cylinders for use on the front of the car, they sometimes use mountings that may not be structurally strong enough, so watch out for that.

They may also have the emergency brake built in.

spitfirebill wrote: They may also have the emergency brake built in.

Didn't stop Subaru

Master cylinder and caliper piston size will have to be used to calculate effective clamping pressure changes, but the hardware is doable.

Some cars don't have the parking brake built into the caliper but have mini" brake shoes etc. inside the rear rotors. Not common but they're out there. The parking brake part of a rear caliper can be removed on many calipers. For my race car I went so far as to make new pistons and blocked off the passage in the caliper body that the parking brake used. Now they work just like a front caliper.

Big pistons in the front, little pistons in the rear, assuming equal number of pots. For example, my race car uses Wilwood Dynapro 4 pots: 1.75" F 1.375" R both w/ 3/4" MCs.

Rear calipers are smaller, have smaller brake pads than the front.

Could seriously affect stopping.

GameboyRMH wrote:

spitfirebill wrote: They may also have the emergency brake built in.

Didn't stop Subaru

And some Saabs.

My friend learned about Subarus the hard way, in an old GL10 sedan. He had watched me perform frequent handbrake turns in my Rabbit on snow covered roads. Then he tried in the Subaru. We both learned about terminal understeer, thanks to Subaru's placement of the e-brake. I am sure he learned how to do his own laundry, too, given the scare he had.

Rear calipers are usually small.

Brembo 4 pot rear calipers is what I was thinking. either audi/porsche whatever guise they sell them as. I need a good quality 4 pot to fit under a 14" wheel, yeah the pad is smaller, but bigger then what came stock on it.

Maybe.

If the pistons are all the same size, it's probably OK. If they have different sizes, it may not be a good idea. Read on.

The problem with multi-piston calipers is the pistons aren't always sized the same. The leading-edge piston is usually smaller than the trailing-edge piston, to prevent taper wear of the pads. This is true for most or all multi-piston Porsche calipers.

Depending on where the bleeder screw is, and which side of the wheel you have to mount the caliper on, you might not have the caliper going on in the right direction. For example, if the rear left caliper is in front of the wheel, and the bleeder screw is on top, the topmost pistons control the leading edge of the pad. If, when placed up front, the caliper is behind the wheel, that caliper has to be placed on the front right so that the bleeder screw is still pointing up.... but not the topmost pistons control the trailing edge of the pad.

I wouldn't use rear calipers on the front of the same car. Rear brakes are typically responsible for about 20% of vehicle braking. Putting them on the front could pretty easily overheat or over-fatigue them. There are obvious exceptions like listed above, but in those cases they didn't put rear calipers on the front, they put front calipers on the rear. In those cases, the rears are overkill. But putting small rear calipers on the front could be way more than they are designed to handle.

But if you're putting (for instance) rear calipers from an F250 on the front of a Miata, go for it.

Careful matching of master cylinder size will be required. You can't just give it correct pressure with the right prop valve, you have to give it the right volume as well.

digdug18 wrote: Brembo 4 pot rear calipers is what I was thinking. either audi/porsche whatever guise they sell them as. I need a good quality 4 pot to fit under a 14" wheel, yeah the pad is smaller, but bigger then what came stock on it.

Then I'd say you're fine as long as you can install them properly like Series said.

Take a look in the dirt track roundy round car catalogs as there are a wide variety of aluminum multi-piston setups on the cheap. As a bonus they all seem to be aimed at 13" wheels which answers a lot of your diameter concerns.

The number of pistons does not necessarily equate to more stopping power.

Depends on the size of those pistons.

If the rears work better for you on space, you can certainly do it.

The next problem is getting the system back in balance front to rear. It may take a limiting valve, a balance bar, or a change in the rear calipers (or wheel cylinders if you have drums) to get the rears in balance so that the back end doesn't lock up on severe braking.