Hi guys,

I recently got a 2004 1500 QC 4x4 5.7L; I believe it has ABS on all wheels. I used to have a 2003 Jeep Liberty without ABS, so it was straight forward to flush the brake fluid.

I've been searching the net and the forum trying to figure out what the differences between flushing ABS brakes and regular brakes are, the service manual talks about using the DRB scan tool for ABS brakes but it seems those cost a few grands. Threads in the forum don't seem to mention anything special about ABS brakes, the same good old procedure is usually talked about.

Are there any differences ? Should I try to do it myself? If so, what should I be watching out for?

Thanks,
Kaveh

 

I've done them just like any other brakes in the past with no problems.

If you have a compressor this is a good tool for changing brake fluid for just about any vehicle:
http://www.harborfreight.com/brake-f...der-92924.html

 

Yeah, I do it the same way.

 

The Scantool pulses the gate to engage the ABS to allow the fluid to be flushed. If you stick to the basic style of flushing, the ABS module gate stays shut and you'll flush everything out.

I've always done the poor mans way, that is, use a One-man bleeder with a reseviour. You pump the brakes enough times until the fluid that comes out is clean. I go around the vehicle twice. I start at the driver rear and go all the way around and do the driver front last.
When you use this method, your using the brake pedal and booster to push the old fluid out(Keep the reseviour topped off!!!) Since you can push the pedal all the way to the floor, this puts the brake pedal past it's point of normalcy. Since brake fluid is veryy corrosive once exposed to the elements, minor leaks past the booster seals are common. This can cause rusting on the piston sleeve. The piston sleeve runs in/out of a seal. Since the brake pedal only goes down 2-3" in everyday driving, rust may have set in on the piston shaft in the "unused" area. When you flush, your putting the pedal so the possible rust areas are scuffing along the internal seal.
Because of this, I really reccomend putting either a block under the pedal to limit the travel to no more than 70%. If you put the pedal to the floor the first time you'll get an idea. No one or a couple of times isn't going to hurt, but you pump your brake pedal a hundred times in this whole process.

 

Yeah, I'm quite familiar with the poor man's way as I myself am a poor man

So if I understand you correctly, by flushing the usual way I will not be flushing the old fluid in the ABS module because the gates will remain shut? Is there a risk of sucking air back into the ABS module?

I read somewhere that I can do a bleed of the four wheels, then take it for a ride and activate the ABS a couple of times, that should open the ABS gates, then bring it back and bleed it one more time. That should be identical to using the scan tool? How important is flushing the ABS module anyways? how much oil does it hold?

 

The small amount of fluid that is in the ABS module will remain there. The rest of the fluid in the lines and calipers is all flushed out but yeah, you could do just that to purify the fluid even more. If your fluid is very dark, then I would suggest that.
Unless it was ordered with 4wheel ABS, you've only got rear wheel so it's a small reseviour for 2 wheels to worry much about the old fluid.

I would reccomend buying the Large Brake containers. Get Synthetic. Valvoline sells a bottle for like $12. You'll only use a little more than half.