Bleeding ABS

[Guzzi-Leif]

I have a 2012 Stelvio NTX with ABS brakes.
My rear brake needs bleeding cause it is full of air and I wonder: Is it the same procedure as older ones without ABS or do I have to include the ABS unit in the work?
Thankful for answer cause I am on vacation in Norway.

 

[GTM®]

Brake bleed is the same as conventionally unless you are replacing the brake line or ABS pump. Be slow and methodical.

 

[uzidzit]

sort of stop by the dealer and have them cycle the solenoid , and pump during a conventional bleed....this is absolutely needed every fluid change,, I liu of this run it up a straight road and lock the brakes that moves fresh fluid throuhout the system when the abs activavates...use5.1 fluid the system will last longger

 

[Guzzi-Leif]

Thanks, Guzzifriends!

 

[canuck1969]

No

sort of stop by the dealer and have them cycle the solenoid , and pump during a conventional bleed....this is absolutely needed every fluid change,, I liu of this run it up a straight road and lock the brakes that moves fresh fluid throuhout the system when the abs activavates...use5.1 fluid the system will last longger

Not absolutely needed. Without cycling u will have a very small amount in the pump. Not an issue. Like Todd said, just bleed and go like they were normal brakes.

 

[uzidzit]

which if you do not activate the system the little that stays inside the valve bodies, and if (glychol based fluid was used dot 3 or 4 will attract enough moisture to cause the valves to stick and pit) over time if not moved through...this is what causes abs pump failures your choice the mew pump assy from MG is about $2600usd, or it can be re-built for $800. 20 bucks at the stealership or any place that does abs service or you can even get the bosch/conti abs code reader maint tool for under $110.

I just mention it as someone that was fucked by piaggio, and had to replace an abs pump control unit at month 4 of Stelvio ownership, I was lucky and found a unit from a crashed bike so it was less than retail but still very high.

The abs unit is not covered under the bikes warranty so be cheap and take your chances

 

[toma nova]

which if you do not activate the system the little that stays inside the valve bodies, and if (glychol based fluid was used dot 3 or 4 will attract enough moisture to cause the valves to stick and pit) over time if not moved through...this is what causes abs pump failures .......

I have flushed brake fluid many times on ABS bikes and never activated the pump. It's just not feasible in one's garage. The amount of brake fluid inside the pump is so little, I don't think there is much risk of contamination and pitting.

A conventional flush (slow, methodic, high-quality fluid that does not introduce any air) is much better than not doing it at all.

With your logic, my two cars' ABS pumps should be falling apart - conventional flushing with DOT4 every two years and my wife's wagon with no ABS activation in four years / 60k miles (and only a few ABS cycles in my hard-driven sport sedan).

Unrelated, what dealer have you been working your warranty issues through?

Tom

 

[uzidzit]

Car abs systems are much more sealed than on a bike and moisture ingress is much slower, but abs control modules avg about 4-5 years even in cars if not maintained properly. many fail and people never know, a single sticking valve won't always throw a code till activation and a pump that is working but marginally IT is just in evidence when used aggressively, any moisture trapped in the system mixed with glycol based fluid breaks down into an acidic state, combine this with fluid boiling and you get etching of the components...contaminated fluid boils going through the valves and pump in abs units it shouldn't but it does on a small level from cavitation here and there as the fluid flows.

I ain't making any money off this advise so I really don't care how your system is maintained, I do know how many BMWs bike abs control modules I have delt with from lack of simple maintence, the Guzzi used the same units with very minor variation

 

[Tomintoul]

Sorry, but that's not right. Brake fluid absorbs water, but doesn't react with it, and even if it were to do so, glycol reacts with carboxylic acids to form esters. I'm not saying that corrosion doesn't occur, but if it does, it's via a different mechanism.

 

[uzidzit]

water and the glycol fluids with heat form fatty acids, And the ph drops, test it this is the same issue we have had for years re-building the DS hydro suspension systems, till the 5.1 full synthetic fluids came out. I just know that when I test the ph test of old fluids they get lower over time when contaminated and heated, also see pitting and etching from cavitation in hydraulic components. as I said before I don't care if you maintain well or poorly, Hell use used motor oil for fluid or windex it only matters if ya don't want ta burn a few k$ at the stealership

here is re-build company that can save you a ton of cash when your abs unit goes tits up, I have used them quite a few times now and they do a good job.

http://modulemaster.com/rebuilds/

 

[Guzzi-Leif]

A whole lotta air coming out...
The pedal is much firmer now but my ear and brain whispers that there is air left in the ABS unit... A test ride will tell - is there rear brake I will be pleased.

 

[uzidzit]

now go for a ride and activate the abs system on the rear (straight line please) then stop at the side of the road and re-bleed, repeat this about three times and the air in the abs unit and its old fluid will be pushed into the lines where you can bleed it out, or cycle the pump with a service tool

 

[Guzzi-Leif]

Test ride today. Rear brake ok.
Thanks for good advices, friends!