Anyone explain to me how the brakes on a mondeo work?

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Sep 18, 2007 | 07:42 AM

^OPM^

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From: just simple old me

Anyone explain to me how the brakes on a mondeo work?

As above how does the outer pad get pulled onto the disc on a mk 2 mondeo when the caliper etc is all bolted onto the hub? and can a sticky/siezed piston in caliper cause the brake pad to only brake on outer part of disc?

Sep 18, 2007 | 08:04 AM

hutton_d

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Originally Posted by ^OPM^

Not sure on the first part but you should find that the outer caliper part slides across on pins. As for the second part - yes.

Dave

Sep 18, 2007 | 08:09 AM

^OPM^

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From: just simple old me

ok-i know it sits inside a bracket that acts as a guide but im wondering how once the piston has pushed the inner pad against disc it gets the outer one to close onto disc as caliper etc cant move as its bolted on-u get my drift?

whats best way to tell if a piston is sticking?-sometimes i get a noise when going very slowly from that wheel but not all times and as i say disc is going rusty on inner part of disc where the pad isn't rubbing against it when braking like it should.

When i jack car up i can turn wheel by hand so it isn't siezed on but just in one spot it makes a rubbing noise when i turn wheel.

Sep 18, 2007 | 10:15 AM

vindaloo

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From: South Bucks

1/ the main "body" of the caliper "floats" on a couple of slides/pins. If all's working well, pressure is equal on both pads.

2/ Yes, stuff can stick.

The slides/pins can get corroded if the seals are damaged or are a crap design or get old and split.

Some alloy calipers have pad plates mounted to allow the pads to move smoothly and provide a hard surface which won't get worn away by pad movement and jittering. If it's designed and implemented right, no problems, however, some calipers suffer from the alloy reacting with steel pad plates. these push on the pads and can jam them. The pressures can result in them buckling or scoring and jamming the pads in place.

J.

Sep 18, 2007 | 12:03 PM

Shark Man

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From: Ascended to the next level

Easy was to see for yourself if you can't visualise it....remove the pads, push the piston back into the body then put the caliper back on without the pads**.

Now push the caliper back and forth (the caliper...not the bracket

), it should slide back and forth with some light effort. Then, providing its not sticking you will go "ahhhhh, I see".

This is what is known as a sliding or floating caliper. And pretty much all cars with the caliper pistons on just the one side of the disc will use the same principal.

** replace pads, caliper, wheel and give brake pedal a few pumps before driving

Last edited by Shark Man; Sep 18, 2007 at 12:08 PM.

Sep 18, 2007 | 08:23 PM

hutton_d

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The other thing that can happen is that the pad itself is too tight a fit inside the caliper. That is, the pad slides in and contacts *lightly* against the caliper. The piston moves and pushes it (hopefully!) against the disk. If the caliper/pad get full of crud then the pad can stick. With a friends car the pad was actually stuck so solid that I had to hammer it out. Piston was fine but the pad was solid so only one pad was contacting the disk each time she braked. Not sure if it was the pad which had a too thick covering of paint or the caliper was slightly distorted. Anyway, the fix was to file down the edge of the new pad so it slid easily in and out. I hasten to add that material was only removed from backing of the pad - not the braking material.

Something else to check ....

Dave