GT-1? Meh. Brake bleed done wrong. :(

[colin]

So. In prepping for Thunderbolt, I was bleeding my brakes. Left front had a problem, circuit was opened too long, and lots of fluid came out. Continued to bleed with a Motive pressure bleeder until no bubbles were observed.

Brake pedal now floors easily. Ouch. I get some pressure if I pump it with my foot. With the engine off, I can even get the pedal rock solid. But as soon as I start the car, no brakes again.

Traditional internet wisdom is that I've likely gotten air into an ABS or DSC pump (2001 e46), and that I'll need to find some shop with a GT-1 to bleed the system while cycling the above pumps/valves to get the air out of there, too. So:

1) do I really need such a machine to get air out of the ABS/DSC system? Or is there another hidden method?

2) is there a member with a GT-1 that I could bribe with beer or something? Or am I stuck going to a shop for a $200 brake bleed?

3) Brakes are for sissies anyway?

4) I probably just need to bleed the whole system again, starting over from right/rear? I'd have done this yesterday but it was pouring.

Your input appreciated, even if it's "Colin, you're an idiot." Thanks in advance.

[jnscaldwell]

There is a way to jump the ABS pump relay and have it cycle without using a GT-1. However, I have not done this before. If you can pinpoint the relay location it should be pretty easy to do. Perhaps Vic can comment.


PS - I know I might get flamed for this, but I am not a fan of the pressure bleeders and refuse to use them on any of my cars. I seem to get better results with a helper using the "pump the pedal" method.

[SmokeyDP]

Just put some channel lock pliers on the one line to get you through your track day.

[m20power]

Colin,

Take it out and invoke ABS several times. I believe that this will cycle the ABS valves and pumps and push the air back to the reservoir. Nice day for it.

Vic may confirm.

Bob

[gfield]

Colin +1 for Bob's comment, cycling the ABS in the wet should push it around/out of the unit itself. Another professional mechanic recommended the same solution when I was having some issues with my ABS last winter.

Greg Field
1997 Boston Green M3 coupe

[kishg]

sell that POS and get an e30 already

[kishg]

bob's right though, initiate abs pump to force the air out, it's the same thing the GT-1 will do. I need to do the same on my dually.

[staianoa]

Colin... you're an idiot.

[staianoa]

I've said it before but this is a perfect example of a use for a Bavarian Technic Tool. The tool can activate the ABS module (and most any other module) on most modern (1996-and newer) BMW's. It's much more capable than a simple code reader and the tool can be used with the free software and anyone's laptop. At about $700 for the professional, it would be money well spent in diagnosing and repairing all these "newfangled" electronic systems that Mike Miller loves to hate.

[momoboy]

Colin, if someone had a GT-1, the following items could occur:

Even if someone had a GT-1, they would not let you use it. We all know you are inept and would charge you $150 to do this because we are mean

They would cycle your ABS but turn off your alarm, reset all your key personalization, turn on your daylight running lights, reset all your radio presets and set everything to celsius and Km where applicable

[SmokeyDP]

I still stand by my suggestion

[colin]

I still stand by my suggestion

heh. I lubv you guys. <sniff!> ... Jerks.

ok well it'll be hard to engage the ABS because 1) the pedal is *really* soft, and 2) I'm in Texas where it's 90 degrees and sunny.

So who wants to either take my car out for a spin in the rain while I'm away, or else lend me their Bavarian Technic tool in return for beer? If it works, I'd totally buy one.

[SmokeyDP]

There is a way to jumper the ABS using the relay so that the pump activates without driving the car.

http://www.m3forum.net/m3forum/showpost ... stcount=13

[staianoa]

So who wants to either take my car out for a spin in the rain while I'm away, or else lend me their Bavarian Technic tool in return for beer? If it works, I'd totally buy one.

Colin... unfortunately most people have the enthusiast version of the cable which is limited to 3 VINs (for about $300). The Professional Version (which the club could obtain) is unlimited (for about $700). Cable works great. I use mine all the time!

[victory1auto]

Given that you say you have "no brakes", it would be hard to get the ABS to activate and hopefully discharge trapped air. Indeed, this approach might cause the internals of the ABS to actually injest more air, depending upon where the air is located now.

I think I would try reverse bleeding, by introducing clean brake fluid to the calipers and pumping it backwards through the lines, ABS/DSC and to the master cylinder. An inexpensive Phoenix Injector can be used for this.

Unless you are familiar with with fooling around with the ABS/DSC, I would avoid trying to jumper points to get the pump to run and to cycle the isolation and dump valves. In any case, try the other suggestions first.

Although I do not recommend "foot-pedal" brake bleeding [No flame intended, Jeff, just a difference in opinion.], in your case you might try it as it can provide much more pressure to the system than can a pressure bleeder.

Vic