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Discussion Starter #1
My brake pads are relatively worn and I am low on brake fluid (according to the light on my dash)

Should I change my brake pads first then do the brake flush or brake fluid flush then brake pad change?
 

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Change the pads, then flush the brake fluid

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Just when you will be changing the pads, open the bleeder valves when pushing the calipers back in - if you don't you will push all the gunk up to the master cylinder and good bye seal.
 

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Discussion Starter #4
Just when you will be changing the pads, open the bleeder valves when pushing the calipers back in - if you don't you will push all the gunk up to the master cylinder and good bye seal.
As in open both bleeder valves at the same time then push the calipers back in? Thanks
 

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Change the pads, then flush the brake fluid.
Is more best to change the fluid FIRST as it's possible (and very likely) that when pushing the caliper pistons back into the caliper the dirty fluid will get pushed back to the MC through the ABS valves. Which is bad.

Change fluid first. Pump at least a "pint past clear" through each corner doing the inside bleeder first. Then 1/2 pint past clear on each outside bleeder.

Lastly, have a helper (or rig a device) to hold the brake pedal mid-level, without movement, while opening an individual bleeder screw and pushing back the associated piston(s) - lever between the rotor and work pad surface - DO NOT lever on the pistons), remove worn pad, install new lubed pad, close bleeder screw,

Lather, rinse, repeat for remaining pads/corners.

Be sure to get brake peddl pressure when finished - pump pedal as needed to bring the new pads in contact with the rotors. Then top (to full line) MC level.
 

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Be sure to get brake peddl pressure when finished - pump pedal as needed to bring the new pads in contact with the rotors. Then top (to full line) MC level.
This always gets me. I always roll out of the garage and get cold sweat trying to "find" my brakes :D
 

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Discussion Starter #7
Is more best to change the fluid FIRST as it's possible (and very likely) that when pushing the caliper pistons back into the caliper the dirty fluid will get pushed back to the MC through the ABS valves. Which is bad.

Change fluid first. Pump at least a "pint past clear" through each corner doing the inside bleeder first. Then 1/2 pint past clear on each outside bleeder.

Lastly, have a helper (or rig a device) to hold the brake pedal mid-level, without movement, while opening an individual bleeder screw and pushing back the associated piston(s) - lever between the rotor and work pad surface - DO NOT lever on the pistons), remove worn pad, install new lubed pad, close bleeder screw,

Lather, rinse, repeat for remaining pads/corners.

Be sure to get brake peddl pressure when finished - pump pedal as needed to bring the new pads in contact with the rotors. Then top (to full line) MC level.
So will I need more than 1 liter to complete a full flush? I only purchased one liter of ATE blue.
 

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Why the flush?
I have almost 200000 miles on my X MR and I always pushed the pads back with never a problem. I never seen someone reaplace the fluid because of new pads.
Racing guys yes, For aggressive DD in my 200000 miles I never needed it.
I’m on my 3rd set of rotors and probably the 6-8 set of pads that were always pushed back.
Currently aero two piece rotors and some great pads.
My X stops way better than stock!
Still original 2010 brake fluid.
I never added or topped off the fluid ever, brake fluid is clear too.
Maybe I’m just lucky?
 

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Why the flush?
I have almost 200000 miles on my X MR and I always pushed the pads back with never a problem. I never seen someone reaplace the fluid because of new pads.
Racing guys yes, For aggressive DD in my 200000 miles I never needed it.
I’m on my 3rd set of rotors and probably the 6-8 set of pads that were always pushed back.
Currently aero two piece rotors and some great pads.
My X stops way better than stock!
Still original 2010 brake fluid.
I never added or topped off the fluid ever, brake fluid is clear too.
Maybe I’m just lucky?
Then you've been doing it wrong all these years.

Do you change your engine oil?? All fluids wear out, absorb moisture, collect dirt, etc.

Not lucky - more stupid. IMHO.

Get yourself a brake fluid moisture tester. Test the fluid in the MC and then pump 100cc out of a caliper and test that too. I've got $20 here that says your fluid has at least 2% water in it now (that means it should have been changed 3+ years ago).

While you're at it, price a new/replacement ABS block.
 

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ok someone explain to me how brake fluid gets dirty in a sealed system? there shouldnt be anything contaminating your brake fluid system other than heat and possibly a small percentage of water over time. so when pushing in your piston (you should be able to do this with your bare hands, otherwise you have a problem) there shouldnt be any sort of gunk going into your system waht so ever
 

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ok someone explain to me how brake fluid gets dirty in a sealed system? there shouldnt be anything contaminating your brake fluid system other than heat and possibly a small percentage of water over time. so when pushing in your piston (you should be able to do this with your bare hands, otherwise you have a problem) there shouldnt be any sort of gunk going into your system waht so ever
Brake fluid is very hygroscopic. Nothing is 100% sealed against air, there is water in the air, the brake fluid will absorb this.

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Why the flush?
I have almost 200000 miles on my X MR and I always pushed the pads back with never a problem. I never seen someone reaplace the fluid because of new pads.
Racing guys yes, For aggressive DD in my 200000 miles I never needed it.
I’m on my 3rd set of rotors and probably the 6-8 set of pads that were always pushed back.
Currently aero two piece rotors and some great pads.
My X stops way better than stock!
Still original 2010 brake fluid.
I never added or topped off the fluid ever, brake fluid is clear too.
Maybe I’m just lucky?

yes your are. I bleed my brakes every 3 years for preventive maintenance. Brake fluid retains water every time you open the MC to do a fill. This can cause a loss of brake when needed the most.
 

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ok someone explain to me how brake fluid gets dirty in a sealed system? there shouldnt be anything contaminating your brake fluid system other than heat and possibly a small percentage of water over time. so when pushing in your piston (you should be able to do this with your bare hands, otherwise you have a problem) there shouldnt be any sort of gunk going into your system waht so ever
Getting "dirty" is different than retaining moisture (water). But the "dirt" comes from the brake system itself: calipers, pistons, seals, lines, valves, etc. All of those items give off somehting, which gets stored in solution in the fluid. And the more moisture in the fluid, the more dirt in the brake components. Brake system parts are not medically-sterilized / clean parts.

Where does the water come from? The air. Same stuff you and the engine breathe. The MC housing is plastic - water vapor moves right through it (BTW - NEVER buy brake fluid in plastic containers - if you do, toss it within a year). Does your brake system still have rubber / neoprene / viton hoses and/or seals? Those things also let water vapor through. So water gets into the fluid, and moves pretty freely through it - just like water in E85. And the fluid (and E85) degrade over time. The limit for the longest-lasting [non-synthetic] brake fluid is three (3) years.

If you track or get the fluid hot, different things happen. Some fluids aerate (get air bubbles), some turn to gel, some change color and viscosity. If you want to see what our particular fluid does when heated, put a liter into a pressure cooker with a thermometer and heat it on the stove to 450F. Let it cool, open the cooker and inspect. FYI: It won't be pretty. If you're feeling lucky, also try 500, 550, 600F.

Brake fluid absorbs moisture quicker at elevated temps.

Brake fluid retains water every time you open the MC to do a fill.
No need to even open the MC cap. The cap and body are plastic and the flex lines are rubber-like. All freely allow water vapor to pass.
 

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This always gets me. I always roll out of the garage and get cold sweat trying to "find" my brakes :D
I've seen an apprentice mechanic roll out of the garage right into another customer's car after doing a brake job because they didnt pump the brakes before reversing.
 
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