How to cycle ABS?

[RnR]

I'm a brake newbie... but now looking at what is eventually required to do a proper brake system bleed/flush when things warm up a tad.

But I'm a little puzzled by mentions of the need to "cycle" ABS systems. What is required to do this - something electronic or mechanical??

The expectation here is that I will be doing a system pressure bleed with a Motive gizmo "by myself". This would be on all 4 wheels and doing it properly with awareness given to anything special pertaining to my Grand Prix's ABS needs.

 

[bulwnkl]

You can interface through the computer to make it cycle the ABS controller. Or, you can take the vehicle out and panic stop it a few times to cycle it. Your choice, but if you're looking for 100% purity the computer route will allow you to flush less fluid through to achieve that.

 

[JHZR2]

I just change the fluid when the manual says so... and then make a good attempt to do a few stops on snow and ice in the winter. Not perfect, but 18 year old ABS systems work perfectly.

 

[GMBoy]

A manufacturer specific scan tool (like Tech 2 for GM) is best. You can cycle the ABS module and get the old fluid out without needind to drive the car and force panic stops. I also know OTC makes a nice ABS only scan tool, but it's expensive for the little use you'll get from it. But, if you change the fluid regularly like JHZR2 says, you'll do just as well as the new fluid mixes.

 

[onion]

I see that you're in MI. I'd expect that your antilock brakes cycle all the time with all that snow & ice.

 

[RnR]

Yup - they don't cycle THAT often, but certainly do periodically this time of year.

The issue (as it appears to this novice) is that I want to pre-lube the nipples and let 'em soak, hook up a Motive bleeder to the master cylinder, feed in some Castrol GT LMA (if I can find it), do a OBD-2 ABS cycle (yes-no-maybe) on each wheel in proper sequence and be done with it.

I have a laptop with a USB/OBD2 interface and some marginal software - which MIGHT be able to do the trick. However, something tells me though that the ABS cycle isn't directly supported in the software.

Perhaps I can send the appropriate code to the ECM and do the trick manually, albeit electronically???

 

[RnR]

Originally Posted By: JHZR2
I just change the fluid when the manual says so... and then make a good attempt to do a few stops on snow and ice in the winter. Not perfect, but 18 year old ABS systems work perfectly.

I'd like to be able to do that - but I detect that the braking is softer than I prefer, and certainly in comparison to newer cars. So I think it best to clear out the entire system.

 

[GMGuy]

Bleed fluid as you normally would. Go for a drive. Find a dirt road to keep it easier. Check for cars behind you (ie: nobody in sight). Slam the brakes to the floor and hold it. Repeat as often as you wish. =-) Bleed/flush fluid again.

Alex.

 

[GMBoy]

Originally Posted By: RnR
Yup - they don't cycle THAT often, but certainly do periodically this time of year.

The issue (as it appears to this novice) is that I want to pre-lube the nipples and let 'em soak, hook up a Motive bleeder to the master cylinder, feed in some Castrol GT LMA (if I can find it), do a OBD-2 ABS cycle (yes-no-maybe) on each wheel in proper sequence and be done with it.

I have a laptop with a USB/OBD2 interface and some marginal software - which MIGHT be able to do the trick. However, something tells me though that the ABS cycle isn't directly supported in the software.

Perhaps I can send the appropriate code to the ECM and do the trick manually, albeit electronically???


You're right, that won't do it. And the only way to send a signal is via a proper scan tool. Or when driving.

 

[swalve]

On my Grand Prix, the ABS module has bleeder plugs.

 

[RnR]

Originally Posted By: swalve
On my Grand Prix, the ABS module has bleeder plugs.

How old is yours??

 

[swalve]

97