Bleeding ABS Brakes

[thestig]

I have just fitted new discs and pads to my Calais (thanks for your help Reaper) and wish to bleed the brake system as the fluid in there is getting a little old and has probably absorbed a fair amount of water over the years.

I was wondering if anyone knows the procedure for bleeding the ABS module. Does this need a command to be sent from the ECU in order to cycle the module. If so am I able to kludge something up in the garage as a work around or do I need a Holden interface/diagnostic unit for the ECU?

L8r

 

[wildss]

Bleeding ABS Brake Systems

 

[Not_An_Abba_Fan]

If you are bleeding them to get air out, then you will need a Tech 1 to cycle the ABS module. If it is just to flush the system, then just bleed as normal. Make sure you keep the reservoir topped up and don't introduce air into the system.

 

[thestig]

Flushing

Its just to flush the system.. There is no air. I just wanted to be thorough as the ABS module doesn't get a lot of use and therefor has probably has the same fluid in it for the last 17 years.

L8r

 

[Not_An_Abba_Fan]

Whether it gets used or not, if the fluid has ever been changed, it would have been changed in the ABS module as well. Flushing the system pushes fluid through everything.

 

[Cheap6]

There will be a small amount of fluid that remains trapped in the ABS modulator, in the pump and pressure accumulator. As best I can determine that will slowly be mixed back into the main system as the ABS self tests on start up.

Maybe bleed the system once, then drive it for a month or two and then bleed again?

 

[Not_An_Abba_Fan]

The amount of fluid that is left in there is bugger all, it won't really affect the performance of the new fluid. Flush it again if you want, no harm in doing it twice.

 

[stocky]

Bumping an old thread, but I need help. I'm about to install a VT master cylinder on my VR, and this involves bending one of the lines from the ABS to the master, so I would assume air is going to get in the line? Will I need to bleed the ABS once I've finished installing the new master cylinder?

 

[Turtl3]

Bumping an old thread but i have the same question. I think i need to bleed the abs module after removing a line between the master cylinder and abs unit? I found alot of moisture buildup in the reservior (fluid had turned thick and greasy) so i gave that a thorough clean and bled all the brakes starting at the furtherest caliper and working fotward in sequence. Pedal feels fine and firm when cars not running - the pedal will stop solid at about half travel on the second pump with the car off. But when the car is running, i can depress the pedal the whole way to the floor and it just feels spongy, the brakes still work but i.m.o its not the same as it was before i removed the line between master cyl and abs unit. Car is a ls1 vx calais. Im thinking i might be able to pulsate the abs unit for the rear brakes (which was the line removed) by putting the rear of the car on jack stands and letting it idle in drive and slowly bringing the revs/speed up with the traction control still engaged(which in theory should make the abs work as the rear wheels will be rotating and the fronts will be stationary) thoughts?

 

[Jxfwsf]

Nope, with tc on it'll think the rear wheel have lost traction and won't rev.
Chances are it'd try to pulse the fronts as they are stationary or log a fault code thinking the front sensors are cactus with no feedback turning the abs off completely.

Different systems on the old VN compared to VT/VX anyway.