Brake fluid change - cycle ABS?

[roadster-nh]

I've searched quite a bit, but couldn't find an answer to this. I'm planning to change my brake fluid, but I'm wondering if the ABS valves must be cycled in order to do a complete change? Or is it an in-line system and the fluid will change using standard bleeding procedures? I plan to use a pressure method (vs. vacuum).

Thanks.

 

[mikebontoft]

you will need to find someone with a scan tool capable of bidirectional control so you can activate the ABS module... otherwise vacuum bleed the system or use speed bleeders. (for a personal vehicle, these things are awesome!)

 

[4RunnerFan]

you will need to find someone with a scan tool capable of bidirectional control so you can activate the ABS module... otherwise vacuum bleed the system or use speed bleeders. (for a personal vehicle, these things are awesome!)

I also have never changed out the brake fluid in a 4Runner before, but I have on other vehicles using a system that creates a vacuum at the wheel and draws the fluid through the system that way. (Hook up line to bleeder valve, pump device a number of times to create a vacuum, then open the bleeder valve and watch the fluid get sucked into container on the garage deck. Repeat when the vacuum draws down after making sure there is adequate fluid in the master cylinder). It is a one-person system that works very well, but not sure if it would work on my T4R. Thoughts?

 

[mikebontoft]

That is a vacuum bleeder and it works too. As with any ABS system, just make sure you DO NOT allow your master cylinder to run dry as you will end up having to bleed the air through the accumulator... that which requires a scan tool to do.

Speed bleeders are nice. I don't have them but wow are they awesome. they use a check valve, so when you step on the brake, fluid is expelled but no air can get in. No vacuum bleeders needs, they install in place of the factory fittings as well. I think they're about $12 a pair.

 

[roadster-nh]

Thanks for the input.

So if I use a Motive-like device to apply pressure to the fluid reservoir and then bleed each wheel, will that also flush out the ABS pump? From what I'm reading the answer appears to be no.

 

[mikebontoft]

No, because the ABS module physically stores pressurized brake fluid in the accumulator and will apply this pressure when necessary.

 

[roadster-nh]

That makes sense and is kind of what I thought. Thanks.

 

[fourwd1]

Whether you're using speed bleeders, power bleeders, or pumping the brake pedal yourself, there's a proper order to do it.
First know the proper bleed order for your vehicle. For instance on early runners it's LR, RR, RF, LF, LSPV.
Next, with ABS systems, do a complete bleed with the engine off.
Then the entire sequence with the engine running.
The again with the engine off.

That's the minimum.