Where's the 02 sensor

should ignition key be set to on before bleeding?

negative....just pedal power needed

I'll get back with the results just that the back ones are so grabbed I WD'd them yesterday twice then earlier today and still cannot unscrew it loose.

Can I understand the front ones have been done....? Check for results after each successful bleed. If things improve, consider that better can be the ennemy of good...

The fronts have been done now but the lights are still on and while driving sometimes it brakes normal but other times goes to the bottom. The 2 back bleeders cannot be loosened, it gets rounded because of rust. I'm completely sure there's not visible leaking, all circuit looks clean from fluid as well as back of the wheels, master cylinder looks clean too (the picture I've uploaded depicts that) so I'm clueless (of course I am since I have no idea of mechanics LOL).
I also bled it from the two bleeders I saw next to the brake master cylinder)
For what I understand when a solid amount of fluid is coming out means there's no air, isn't it?

...sometimes it brakes normal but other times goes to the bottom....
...this is not really typical of trapped air....my son had experienced something similar with his Z-34....the master cylinder was shot...but there was a cause...the previous owner had used automatic transmission fluid instead of brake fluid..:eek7: all lines and cylinders had to be bled after the new master cylinder was installed... anyway, master cylinders do fail at times..

..there is still a slight possibility for the rear cylinders....most of the time the brake line enters the cylinder at the top also, at same height as the bleeder...and bleeding can be done by partly unscrewing the brake line instead ; however, it might be no easier than the bleeder itself.

..ya...a solid stream of bubblefree brake fluid is a good sign....there is no mistake bleeding abundantly...making sure the master cylinder never goes empty...the recovered fluid can be reused.

When the mechanic replaced the left line some months ago would have told me if something had gone wrong before I guess.
Any idea what the reason for BOTH lights going on at once could be?
Thank you for your support.

Just read your last paragraph, How do you recover the fluid? I was using shop towel to keep it from falling on the driveway.

I think I can answer that: with a hose and some bottle.

...Any idea what the reason for BOTH lights going on at once could be?.

THe ABS light is almost natural when it is ON....:evillol: ... A failed sensor in one of the 4 wheel hubs is probable. It is not related to the problem you have at this time.
Mine has been ON for years. I don't care. When I had to replace one rear wheel hub a few years ago, the ABS sensor, connector, etc was totally destroyed by corrosion and the other side is probably in the same state. THe rear right hub is the only one that is original. BOth front have been changed several times, and the rear left once. Each ABS sensor is part of the wheel hub//bearing unit. A scan with a dedicated GM unit would reveal which wheel is the culprit. These codes cannot be flashed.

Of course, the BRAKE light turns ON for several reasons, (low fluid level, parking brake applied...) and in your case most probably from assymetric activation of the rear and front brakes...occurs when air is trapped in one of the 2 systems...or for an assymetric (failed) master cylinder.

p.s. out till Sunday..

Thank you LMP.
I know I'm becoming a "bug in your eye" at this point but in this case, strangely, mine was never on until they simultaneously did, can it be a coincidence?
Would you drive 30km. under this conditions? (I've got use it tomorrow)

It is possible the ABS system also recognizes the assymetric problem....or.....could the ABS system cause the problem? I'm just asking myself this question...
When you turn the ignition to ON...do you hear a "mechanical" sound in the power brake area?.....
I'd pull the ABS fuse out for a test... ...well in my '93, the ABS has a separate fuse just for itself.(I used eto pull the fuse in winter..when the ABS still worked). VErify if your fuse block (in the glove compartment) is the same...
www.avigex.ca/xport/fusepanel31.jpg this 3 amp fuse down center...yours can be different because you ('94) have airbags....

Now that you mentioned it I remember that before the lights went on the pedal started to behave weird, at the end of the pedal kind of slide for a sec with a sound that I could describe as "clonk"; I repeat that was brief, one sec. As soon as the lights went on never happened again until the problem became as it is right now.
A friend was telling me yesterday that he purged his truck, also a GM, then drove normally for some days until he experience the same than me, sometimes normal brake sometimes to the bottom, he finally bled all over again despite the solid fluid coming out until one moment when air began to emerge. Maybe I have to insist purging longer to see what happens, but today is raining here.
Oh, my ABS relay and 3A fuse are both in the engine next to each other, do you suggest driving without it?
Thank you

Yes, there is ALSO another fuse next to the relay....
About ABS...there is no problem decomissioning ABS: cars have run without ABS for decades. The idea was to rule out the ABS system as an active cause to your problem...a test is a test....and the result is always informative, be it positive or negative. But....Well...insisting on purging again is not a bad idea. Too bad the rear does not allow an easy solution...

Ok, I'll remove the fuse, it can't hurt anyway.
Also I'll have time this Wednesday afternoon so I'll bleed thoroughly.
Thank you again. I'll come back.

Hi Again, busy week but here I am. The only thing I did so far is removing off both the fuse in the engine next to abs relay and the one in the glove box. Strange that the brake red light went off but the abs continued on. Braking the car hasn't changed, sometimes ok sometimes goes to the bottom but the fluid in the reservoir remains the same.

...Strange that the brake red light went off but the abs continued on.....
Normal the ABS keeps the light ON...just pulling that fuse causes that on top of the rest. But strange the BRAKE light quit while the problem is still there.......insert the glove box ABS fuse back and see what happens........

Sorry I'm too busy these days, mostly sorry for my loved Transport. I reinserted the fuse in the glove box fuse panel, the lights on cluster remain as they were, abs on, brakes off. Braking hasn't changed since I didn't do any bleeding yet.
Just reporting because of LMP support from the beginning.
I'll be back!

I'm still alive. My PC went south and I finished installing a preview copy of Windows 8.
I've discover that my Trans Sport break problem is... wrong fluid was added sometime so now I think I have to replace everything or drop it in the garbage, thing that I do not want to do because it is working fine despite all troubles I've described previously.

LPM: "...this is not really typical of trapped air....my son had experienced something similar with his Z-34....the master cylinder was shot...but there was a cause...the previous owner had used automatic transmission fluid instead of brake fluid..:eek7: all lines and cylinders had to be bled after the new master cylinder was installed... anyway, master cylinders do fail at times.."

I guess I have to begin by replacing the master cylinder then everything has to be bled, then give it a try to see if it works. If it doesn't I'll probably have to replace all wheel cylinders.