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Uneven Front Rotor Wear

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

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FireFox31
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Re: Uneven Front Rotor Wear

Post by FireFox31 »

Here is the CN90 break overhaul thread.

If the piston is seized, is there any way we can free it and make the caliper functional and safe again? My right rear caliper is seized open after having been replaced Jan 2015.

If one caliper is seized, will that prevent the other piston in that caliper (for rears) or the other side's caliper from closing? Both of my rear rotor outer faces are always rusty, but the left caliper works and the right caliper outer bore is seized.

I have had six calipers replaced in 3.5 years. With CN90's thread, I will rebuild them every year so they never seize again.
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bmdubya1198
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Post by bmdubya1198 »

I don't think there's any need a rebuild the calipers every year.
If the caliper is seized and you can get the piston out, whether you use an air compressor or whatever method you choose, you can clean out all the rust and replace the seals. Use CN90's method and you'll be fine.
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Post by abscate »

There is a big operating difference between front and rear brakes.

Rear brakes-two,pistons, each one squeezes a brake pad onto the rotor. If one freezes, that side of the rotor gets dull. Anything but a shiny mirror finish after a week driving town or city means something is wrong.

Front brakes- one piston and a slidingcaliper which pulls the other pad onto the rotor. Either the caliper or piston can freeze up, or both. Again, brake rotors should look like mirrors

If they are freezing up,every year then either the seals are bad or your brake fluid is getting water in it.
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