Procedure for bleeding ABS with VIDA? Topic is solved

[leapdragon]

Hi all,


So with the help of everyone here in an earlier thread, I've today managed to replace 4 wheels of rotors, pads, hydraulic hoses, and calipers (the hoses have long been a sticking point, and like an idiot I've been trying to loosen the front and counterhold the rear, until someone pointed out this was backward).

Now I have the dreaded mushy brakes problem. Car stops okay, pedal holds once bitten, but I have to travel a decent distance for that to occur. Clips on the pads checked and double-checked, they're in there right. Bled all four wheels repeatedly, there are no air bubbles in the calipers or lines going to the wheels.

That leaves the dreaded "some air has made its way into your ABS module" problem. I have VIDA and I can talk to the ABS module. But I frankly don't know what to do. I sat down and activated the pump and some of the valves, but nothing in particular happened other than them activating.

Presumably there's a procedure? Do I need to open bleeder(s)? When? Do I need to pump brake pedal at some point? Do I need to actuate valves one by one and turn on pump? Also, which valves? There appears to be an inlet valve and an output valve for each wheel. Should I just open them all? And then mash the brake pedal? With bleeder(s) open?

Forgive the stupid questions, but I don't want to do anything stupid having come this far.

Any help appreciated.

[vtl]

Get a cheap vacuum bleeding kit, the one that attaches to the bleeder, remove the caliper, press the piston fully in, open the bleeder, suck out some fluid. Repeat on other wheels.

If the pedal is still mushy then it's time for the ABS pump activation via DiCE/VIDA.

[leapdragon]

Indeed, it may be time for the ABS pump activation with VIDA. Which I have at the ready.

But there are a whole bunch of activations under the ABS unit. I have tried playing with some of them at random. I'm presuming there's something more? Is it just the pump I need to activate, and not any of the multiple in/out valves?

When I activate the pump, should I have a bleeder open? Which one? Or do it once for each wheel?

[vtl]

Depress the brake pedal and fix it. Start bleeding the contour and activate inlet/exhaust valves a few times. Because you'll have to bleed the whole contour, make sure you have some extra fluid to top up the expansion tank. You will see bubbles in one of the four brake contours (and maybe in more than one) and then say hello to the completely linear brake pedal.

[leapdragon]

Thanks vtl!

As I went out there this morning to prep for tackling again this evening, I discovered that I'm an idiot. The rear left and right calipers are on the wrong sides, it seems to me—bleeder screw low rather than high. I don't know how I missed it, but it could be that that's the problem and that there are actually still air bubbles in those calipers even though fluid was running out of them without bubbles (don't know how I didn't notice that I was bleeding from the bottom... derp).

So I'll swap those two first and if things are still soft, I'll press ahead with ABS and let everyone know how it goes.

[vtl]

He-he

Push the piston fully in when bleeding the caliper, this is important.

[leapdragon]

So I am indeed an idiot.

Saturday, I spent an entire afternoon bleeding and test driving, bleeding and test driving, unable to get firm brakes. Pressure bled, vacuum bled, two-man bled, etc. Never once did I notice that I was bleeding out of the bottom of the rear calipers.

This afternoon, flipped them around, bled once more just using gravity, and then put the wheels back on and test drove. Brakes are hard as a rock and feel great.

So, for anyone reading this thread: vtl helpfully provided ABS bleed instructions above. BUT before you do that, actually pay attention and see if you have put the calipers on the wrong sides. You should always be bleeding out the top.

[regent]

Point taken, with one exception (from another idiot who's been there, done that same thing
You are not alone.)

'Bleed out the top unless you are in Australia where everything is upside down'

[jonesg]

Thanks vtl!

As I went out there this morning to prep for tackling again this evening, I discovered that I'm an idiot. The rear left and right calipers are on the wrong sides, it seems to me—bleeder screw low rather than high. I don't know how I missed it, but it could be that that's the problem and that there are actually still air bubbles in those calipers even though fluid was running out of them without bubbles (don't know how I didn't notice that I was bleeding from the bottom... derp).

So I'll swap those two first and if things are still soft, I'll press ahead with ABS and let everyone know how it goes.

I read a story about a guy who did that, he even replaced the master cylinder and ABS unit and it still wouldn't bleed.
Then he saw the bleed screw was at the bottom of the caliper...doh.