12_gl450

Hi All, after flushing brake fluid, is there any particular window of time you can change the pads? I hear if its unclean, it will contaminate and potentially damage the ABS when you push the pistons in. Could you change them a month later? year later? Thanks in advance.

Fourdiesel

If the flush is done properly ALL the fluid - including that in the wheel cylinders - will be changed and is NOT contaminated. You hear wrong.

DennisG01

If the brake fluid is "flushed", doesn't that mean that it's "clean". Like I mentioned in your other thread - just think about it. It makes no sense. You either misunderstood or are reading way too much on this interweb thingy.

alx

Op got a point. Unfortunately there is no such thing as complete fluid flush. Regardless of how much you exchange the gummy fluid in the caliper cylinders remains somewhat unchanged.

So flush fluid and then do the pads. No need to wait. Or you can wait a bit (a month is ok unless you track the vehicle).

ddruker

I supposed if you wanted to be ultimately **** about it getting the most possible old fluid out of your system, you could do them both at the same time - flush your fluid while you have each the pads off and the caliper pistons compressed, one at a time.

But this seems to be to ridiculously be overkill. Even the Mercedes mandated 2 year brake fluid change interval feels to me like overkill - I do it, but I don't think you are going to get a lot of "gunk" in the small amount of fluid that's left in each caliper cylinder, particular given how often the fluid overall is getting changed.

And I sure think the likelihood of damaging your ABS system is basically zero, no matter when you change your pads.

So I would just totally not worry about it.

Keyser Soze

It has little to do with 'gunk'.........It's about the moisture that is adsorbed by the alcohol based brake fluid from the atmosphere that can cause corrosion.....

alx

In a properly functioning and sealed brake system moisture absorption by the fluid is not an issue. Gunk/ varnish always is. Dirty fluid is dirty not because of water absorbed but because of dirt.

gl450x164

Curious how a properly sealed system can absorb dirt?

2010GL550

+1 I do the flush every two years also, but it's overkill. Change the pads when you want and stop worrying about the sensor.

alx

This was actually explained to me by an engineer from stoptech- fluid gets dirty in two ways- extreme temps and cooling generating varnish and by the fact that the pistons move ever so slightly back and forth and every time they move back into the caliper they drag a bit of dirt from outside - think peristaltic pump. Eventually some of it makes it past the seals and into the fluid chambers. Amounts each "cycle" are miniscule, but then again persistence is the key.