ABS bleeding and failures

Skeezix

New Member
Founding Member
Joined
Feb 27, 2011
Messages
22
Location
Houston, Texas
I’ve had my S10 since Aug, 2011 and feel it’s time to bleed the clutch and brake system.

The clutch is straightforward, but since the bike has the ABS system, I was wondering if anything needed to be done to flush the old fluid out of the ABS pump itself.
Years ago (think Yamaha GTS1000 from the mid 90’s), fluid was trapped in the ABS pumps and general flushing would not remove all the fluid. Thus, when flushing, one had to ‘trick’ the ABS pump into operation to get all the bad fluid out, otherwise the ABS system would seize up.
There is no mention of this in the S10 shop manual from what I can tell, and was wondering what you guys thought?

Regards,

Skeezix
 

Kelvininin

New Member
Joined
Jan 16, 2013
Messages
178
Location
55374
Re: Brake bleeding - need to flush the ABS pump too?

Get a Mighty Vac hand pump vacuum and suck the new break fluid through the caliper bleeders. I have done this on cars and trucks, should work on a motorcycle as well.
 

Skeezix

New Member
Founding Member
Joined
Feb 27, 2011
Messages
22
Location
Houston, Texas
Re: Brake bleeding - need to flush the ABS pump too?

Thanks for the tip - I have a mightyvac on order now. My question was whether I will need to 'flush' the ABS pump as well as the brake lines. Maybe I should flush the lines, and then go for a ride and operate the ABS system, and then re-bleed the lines again?


Kelvininin said:
Get a Mighty Vac hand pump vacuum and suck the new break fluid through the caliper bleeders. I have done this on cars and trucks, should work on a motorcycle as well.
 

avc8130

Active Member
Joined
Jan 29, 2012
Messages
3,269
Location
North NJ
Re: Brake bleeding - need to flush the ABS pump too?

Skeezix said:
Thanks for the tip - I have a mightyvac on order now. My question was whether I will need to 'flush' the ABS pump as well as the brake lines. Maybe I should flush the lines, and then go for a ride and operate the ABS system, and then re-bleed the lines again?
Do you own a modern GM vehicle?

I get your question, and I have always wondered that also, but Yamaha doesn't mention a procedure for the ABS system specifically that I could find.

I know on modern GMs, to do a PROPER brake fluid flush one needs a Tech 2 to command the ABS solenoids "open". The common "redneck bleed" is to do the flush and then go stomp on the stop pedal in the gravel and then bleed again.

ac
 

Checkswrecks

Ungenear to broked stuff
Staff member
Global Moderator
2011 Site Supporter
Joined
Mar 7, 2011
Messages
11,489
Location
Damascus, MD
Re: Brake bleeding - need to flush the ABS pump too?


Yes, the pump should be flushed periodically. The service manual (pg 4-71) gives 2 versions of how to cycle the ABS pump. The down-side is that both require "Test coupler adapter 90890-03149"


I haven't done mine in too long (1.5 years) so thanks for the reminder. The Mighty Vac won't get what is in the pump circuit.


The way I did it was to bleed out the system thoroughly, then go get it to operate with some hard stops on gravel to cycle the pump. See if the fluid is dirty enough to need to be cycled again, mine did discolor the fresh fluid. DOT4 fluid is cheap.
 

Skeezix

New Member
Founding Member
Joined
Feb 27, 2011
Messages
22
Location
Houston, Texas
Re: Brake bleeding - need to flush the ABS pump too?

You hit on exactly what I was thinking about doing. I'll just flush the lines then find a gravel area to activate use ABS, then reflush. I'm getting technical here, but if I active the ABS by using the rear brake, will that flush the ABS pump enough, or do I need to lock the front brake as well?


Checkswrecks said:
Yes, the pump should be flushed periodically. The service manual (pg 4-71) gives 2 versions of how to cycle the ABS pump. The down-side is that both require "Test coupler adapter 90890-03149"


I haven't done mine in too long (1.5 years) so thanks for the reminder. The Mighty Vac won't get what is in the pump circuit.


The way I did it was to bleed out the system thoroughly, then go get it to operate with some hard stops on gravel to cycle the pump. See if the fluid is dirty enough to need to be cycled again, mine did discolor the fresh fluid. DOT4 fluid is cheap.
 

tubebender

Active Member
Founding Member
2011 Site Supporter
2012 Site Supporter
2013 Site Supporter
2014 Site Supporter
Joined
Jan 6, 2011
Messages
656
Location
Oceanside, CA
Re: Brake bleeding - need to flush the ABS pump too?

I own a GM truck and had to do the 'redneck' bleed after a master cylinder replacement.


Checkswrecks said:
The service manual (pg 4-71) gives 2 versions of how to cycle the ABS pump. The down-side is that both require "Test coupler adapter 90890-03149"
I tried to buy that a year ago from 2 different online dealers. Response was - part no longer availible / discontinued.
 

avc8130

Active Member
Joined
Jan 29, 2012
Messages
3,269
Location
North NJ

tubebender

Active Member
Founding Member
2011 Site Supporter
2012 Site Supporter
2013 Site Supporter
2014 Site Supporter
Joined
Jan 6, 2011
Messages
656
Location
Oceanside, CA

Skeezix

New Member
Founding Member
Joined
Feb 27, 2011
Messages
22
Location
Houston, Texas
Re: Brake bleeding - need to flush the ABS pump too?

So to do the red-neck ABS pump flush, does one need to activate the ABS by locking the rear brake AND the front brake, or will either one work? I already activated the ABS by locking the rear, and was hoping that was enough. Locking the front it something I try to avoid at all costs 8)
 

avc8130

Active Member
Joined
Jan 29, 2012
Messages
3,269
Location
North NJ
Re: Brake bleeding - need to flush the ABS pump too?

Skeezix said:
So to do the red-neck ABS pump flush, does one need to activate the ABS by locking the rear brake AND the front brake, or will either one work? I already activated the ABS by locking the rear, and was hoping that was enough. Locking the front it something I try to avoid at all costs 8)
If you can lock the front, the ABS is broke.

ac
 

Checkswrecks

Ungenear to broked stuff
Staff member
Global Moderator
2011 Site Supporter
Joined
Mar 7, 2011
Messages
11,489
Location
Damascus, MD
Re: Brake bleeding - need to flush the ABS pump too?

Skeezix said:
So to do the red-neck ABS pump flush, does one need to activate the ABS by locking the rear brake AND the front brake, or will either one work? I already activated the ABS by locking the rear, and was hoping that was enough. Locking the front it something I try to avoid at all costs 8)

Locking up the front is counter to what we train ourselves. But in this case it is good for both the ABS system and for you to know how the system works. Let alone how fast the bike can stop.


Try just a few hard quick grabs on grass or gravel, and once you see that you really aren't going to die, do a hard pull on the brake lever from about 15 mph.
 

Bombman

New Member
Joined
Jan 28, 2014
Messages
27
Location
Clarksville, TN
Re: Brake bleeding - need to flush the ABS pump too?

Good read.. I just bought my S10 a few weeks ago. Put on over 800 miles in under a week for break in. When I did my "600" mile services myself, I checked the brake/clutch fluids and found them very brown. They sat in the bike on the showroom floor for almost 2 years. I wasn't surprised. The clutch was very straightforward. The front and rear brakes were another story. You pretty much have to use a Mityvac to do it right. If not you can always do the old vacuum jar where you place an inch or so of fluid in the bottom of a jar and run a hose into it from the bleeder screw and pump pump pump your way to glory! What a pain...do yourself a favor and drop the $30-$50 bucks on a Mityvac. As far as getting the old fluid out of the ABS pump. I simply rode around for a few days and whenever I found a gravel or loose area I would bump the brakes, alternating between front and rear. After about a dozen times on front and rear I flushed again. Surprisingly the fluid was pretty brown/tan again. The clear DOT4 I put in was contaminated and I flushed again. Now it is clear and ready for another couple years.
Why flush the brake system and change the fluid? Brake fluid is VERY hygroscopic, in other words it absorbs moisture from the environment. In a sealed brake system with no air in it how can it still absorb moisture? Condensation will still form in the very small air pocket left in the master cylinders from the normal heating and cooling of the brake fluid reservoir. There is no cycling of brake fluid so the bottom and top 4-6" of fluid is used over and over to push the pistons. At either end of the system is where you get moisture absorbed into the fluid and why it needs changed out every few years. If not that moisture can develop and lead to corrosion in the lines and metallic parts and eventually failure.
 

gmtech

Active Member
Joined
Jan 9, 2013
Messages
174
Location
quad cities
Re: Brake bleeding - need to flush the ABS pump too?


This could turn into a oil debate! haha

anyway I work at a chevy dealer and the new boss man is all about selling brake fluid flushes
he came from Honda and Toyota where they have a interval for flushing brake fluid.
Well GM does not GM states powersteering fluid and brake fluid should last the life of the car
ive worked on cars for 10plus years and I have never seen a brake component fail from "bad brake fluid"
brake lines and componets corrode a lot quicker from the outside in then they do from the inside out.

anyway I prolly will flush my tenere's brakes somtime but im not gonna worry about getting the fluid traped in the abs pump.

just ask Canada paul what he thinks about is abs pump/module!
 

scott123007

Well-Known Member
Joined
Jul 27, 2012
Messages
1,461
Location
Jupiter, Florida
Re: Brake bleeding - need to flush the ABS pump too?

The more popular reason for changing your brake fluid is for performance. The water that eventually finds its way into brake fluid lowers its boiling point. Brakes do not like steam in their lines. LOL
 

Skeezix

New Member
Founding Member
Joined
Feb 27, 2011
Messages
22
Location
Houston, Texas
Re: Brake bleeding - need to flush the ABS pump too?

After the initial flush, I took a ride on a fire road and actived the ABS (both front and rear). After returning home, I found the fluid to be almost perfect. I flushed front and rear again, and the front was slightly brown in color, but rear looked great. Most likely it was more for peace of mind, but it's good to know the system is clean and fresh.

Thanks to all those who responded - I hope others find this thread useful.
 
Top