ABS light

Rallymad

New Member
Joined
Oct 8, 2022
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8
Location
Dublin, Ireland
Hi there have a 13 s10 abs light is on front lever very hard when pulling pump will make noise when I try cycling it this is also only time both pedal and lever go in fully . If pump is cycling does that mean pump is OK. First fault up on diagnostic is 14.
Would appreciate any advice before I remove pump and try have it repaired if it can be .
 

2daMax

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Jun 3, 2015
Messages
677
Location
Penang, Malaysia
The hard pull on the front lever or a hard rear pedal is likely the UBS linked brake ABS valve being sticky. When was the last time the brake fluids were changed? Would be good to bleed both front and rear and then cycled the abs pump. Then partial bleed and cycle the pump a few more times. Each time the valves are actuated, the loosen debris needs to be moved away by pumping out. This would save time and fluids. Heavy suspect the UBS valve is corroded and causing the valve not to slide freely. I learned that the valve can be plated by the free Copper ions that the old brake fluid wasn't able to neutralized. Changing brake fluid on time for a ABS equipped vehicle is crucial. With DOT4 fluids being more hygroscopic than DOT3, the change intervals should a lot sooner than if using DOT3.

I am having the rear being hard. Have bleed and cycled but haven't tried riding the bike. If I solve this, I will be doing a yearly brake fluid change.
 

Rallymad

New Member
Joined
Oct 8, 2022
Messages
8
Location
Dublin, Ireland
The hard pull on the front lever or a hard rear pedal is likely the UBS linked brake ABS valve being sticky. When was the last time the brake fluids were changed? Would be good to bleed both front and rear and then cycled the abs pump. Then partial bleed and cycle the pump a few more times. Each time the valves are actuated, the loosen debris needs to be moved away by pumping out. This would save time and fluids. Heavy suspect the UBS valve is corroded and causing the valve not to slide freely. I learned that the valve can be plated by the free Copper ions that the old brake fluid wasn't able to neutralized. Changing brake fluid on time for a ABS equipped vehicle is crucial. With DOT4 fluids being more hygroscopic than DOT3, the change intervals should a lot sooner than if using DOT3.

I am having the rear being hard. Have bleed and cycled but haven't tried riding the bike. If I solve this, I will be doing a yearly brake fluid change.
Thanks for that ill give it a good bleed and see how it gets on previous owner did very little millage on it only has 6500 miles on her in 10 years fluid looks OK not scummy but ill change it now see if that works .
When the ABS pumps fail what happens them ? Will they do a recycle if there faulty ? As mine will do the recycle but when it does it both break lever and pedal will go soft for a few seconds allowing you to pull it in fully before returning to a fairly solid lever just trying to rule everything out before I rip out the pump and send it off to be repaired if it can be.
 

2daMax

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Jun 3, 2015
Messages
677
Location
Penang, Malaysia
When the ABS fails in terms of the valve block area, then the valves gets sticky and trapped air (probably the by products of moisture and corrosion process creating vapor).

If they goes soft on the lever or pedal, it is just trapped air that is needed to evacuate out via multiple ABS valves actuation.
 

Rallymad

New Member
Joined
Oct 8, 2022
Messages
8
Location
Dublin, Ireland
Tonight I fushed the brake lines on my s10 flushed ok I always had a firm front and rear easy enough. Then went to cycle my ABS pump but it would not recycle I have in the past tried this to fix my pump and it would run through the cycle but it won't do it now sometimes it makes a few noises at the start but won't do the cycle system like it was before has the pump just given up or has my flushing made it worse at my wits end with this ABS pump
 

Rallymad

New Member
Joined
Oct 8, 2022
Messages
8
Location
Dublin, Ireland
More news on my ABS pump any advice on this on going saga greatly appreciated.
I gave the rear another bleed just incase an air bubble was airlocking the ABS then I jumped the wires again and tried the pump cycle could feel I little squeeze in the lever but not doing the proper cycle which is unmistakable anyway nothing happened so I saw somewhere about putting the bike in gear 2nt with stand down which I did and tried the cycle again .
The pump started to run and it didn't stop I turned off the key and it still stayed going I had to disconnect the battery to stop it???
I now have the main 30A fuse pulled out I rode the bike to see with pump running if that would stop it but no so then removed 30A again and I had brakes which is where I'm at now .
Has anybody heard of this happening before ? Is a new pump the only answer ?
Is that even the problem totally baffled other than that bike is great .
 

WJBertrand

Ventura Highway
Joined
Jun 20, 2015
Messages
4,553
Location
Ventura, CA
Have you double checked that you’re jumping the correct wires?


Sent from my iPhone using Tapatalk Pro
 

2daMax

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Jun 3, 2015
Messages
677
Location
Penang, Malaysia
There is probably a short in the wiring that powers the ABS. Tracing the wiring will be time consuming unfortunately. I believe the Service Guide has schematics for the ABS, and can check how the ABS motor is connected.
 

Rallymad

New Member
Joined
Oct 8, 2022
Messages
8
Location
Dublin, Ireland
There is probably a short in the wiring that powers the ABS. Tracing the wiring will be time consuming unfortunately. I believe the Service Guide has schematics for the ABS, and can check how the ABS motor is connected.
Was thinking would it be a stuck solenoid or something but as you say what's powering it
 

2daMax

Active Member
Joined
Jun 3, 2015
Messages
677
Location
Penang, Malaysia
If I remember correctly on the ABS electrical schematics, the Motor relay is built into the ABS Module. If this Relay switch is stuck 'closed' then that would explain the direct power to run the motor even when the key is off. It is likely a Solid State switch vs a magnetic mechanical switch (like the starter relay).

Has it like resolved?
 
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