IS ABS Module is a weak spot of this bike

Jlq1969

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May 5, 2018
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Argentina
will that not let air in tho
EDIT:):…..Open the bleeders, and then push the pistons and before finishing pushing the pistons, “close the bleeders”…so you avoid dirty fluid (in the caliper), going up to the abs module…
 

RCinNC

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Aug 30, 2014
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North Carolina
I'm another offender. Changing brake pads is one of those maintenance tasks that seem so basic that you don't bother to look it up in a service manual. It's something I've never done in the almost 100,000 miles I've had the S10, but right there on page 4-66 of the service manual it says to loosen the bleed screw before you push the pistons back into the caliper. I've started doing it since I first read about it on this forum, though I suspect if I did any damage, it would have appeared by now.

As far as pushing dirt from where it settles in the caliper back into the ABS module when you compress the piston, I'm not 100 percent convinced that's the reason for opening the bleed screw. It's gotta be around 18" from the rear caliper to the ABS module. When you compress a piston during a pad change, how far are you pushing it? Maybe a quarter inch max? Would that really be enough force in a closed system to push debris out of the caliper and make it travel those 18" all the way to the ABS module? The fluid itself barely moves in a hydraulic brake system; that's kind of the point of a hydraulic system. Pressing a piston into the caliper will cause an increase in system pressure, and it maybe causes some cavitation inside the caliper, but moving dirt through a fairly viscous fluid (compared to water, anyway) against gravity all the way up to the module, when the fluid itself barely moves? I dunno, I'd like to see a practical demonstration of that before I agreed that was the reason for doing this.
 

Steve in ATL

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Aug 8, 2011
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Atlanta, GA USA
Again: my question is “Is the theory that pushing fluid backward through the ABS motor that it *damages* the ABS unit, or is it simply contaminated and in need of flushing rather than replacement?”
 

Cycledude

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Jan 29, 2016
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Rib lake wi
I have never opened a bleeder in order to push the piston back in but now that it has been mentioned here I will probably start doing that. One thing I always do before pushing the pistons in is spray them with brake cleaner and clean them with a toothbrush to help prevent pushing dirt into the caliper.
 

bimota

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Dec 10, 2017
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bridgend, Wales, UK
Again: my question is “Is the theory that pushing fluid backward through the ABS motor that it *damages* the ABS unit, or is it simply contaminated and in need of flushing rather than replacement?”
i,d say no, i would bleed the brakes a few more times and keep cycling the pump it should come good
 

WJBertrand

Ventura Highway
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Jun 20, 2015
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4,507
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Ventura, CA
Regardless of the contamination question, opening the bleeder makes the pistons a lot easier to push back in.


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