Help With E38 Brake Bleeding Procedure! Seriously?

[masbury]

The Car: 1998 750iL (Pre-Facelift) 120K miles

I bought it cheap and knew it needed brakes, so literally did it all!

Replaced:
Master Cylinder
Rotors (Front and Rear)
Pads (Front and Rear)
Rebuilt Calipers
Installed SS brake lines

All that went great, it's the bleeding that's killing me.

Checked the TIS and it says:
Pressurize the master cylinder to 29psi (I have a Motiv pressure bleeder)
Start with right rear, run "Bleed" procedure in GT1 (which fires up the ABS pump)
Carefully pump the pedal (do not exceed the stop)
Close the bleed screw
Move on to the left rear, then right front and finally left front. Rinse and repeat...

I have put somewhere in the vicinity of 5 gallons of DOT 4 brake fluid through this system and still cannot get clear bubble-free brake fluid out. I can't be the only guy who has had to change a master cylinder in one of these things, allowing a butt-load of air into the system. Gimme a break! I did this same job with my 850 E31 and had no problems at all.

Does anybody know if there is some kind of "trick" to this, because I'm really sick and tired of bleeding brakes. It's pretty much all I've done for a friggin' week.

Help!

[masbury]

Really! Are you all telling me that either no one but me has had to bleed E38 brakes, no one has ever had this problem or I'm doing everything right.

Please let me know which it is, so I can stop bleeding brakes!

[Roont]

This is from my experience while at vw. After the abs and pressure bleed, sometimes we did have to do it with a second person to force the final air out. And it was always one wheel, just a but of foam between us and flagging good time haha. Our pressure bleeder towards the end of its diaphragm life would get weaker and weaker needing to just bleed without it until our foreman would replace it

Sent from my VS501 using Tapatalk

[gusdog]

Are you getting bubbles at all four corners or just one? Do you have good threads at each bleed nipple? I've had a situation before where I was pulling air through the nipple threads and could never get clean fluid. Wrapped the threads in teflon tape and problem went away.

Other than that, I've got no new insight.

[masbury]

Thanks for the reply's!

Yes, the bubbles are coming from all four wheels. I'm really stumped! I may have to employ the 2 person method just as a final push. Other than that, I don't have a clue.

Thanks again

[masbury]

Update;

Finally! No more bubbles! All it took was 28 hours of continuous bleeding running both preload pumps alternatively, the ABS pump and pumping the pedal.

I never want to do that again!

[lapd1989]

Thanks for the reply's!

Yes, the bubbles are coming from all four wheels. I'm really stumped! I may have to employ the 2 person method just as a final push. Other than that, I don't have a clue.

Thanks again

That is crazy bro.... what happen?