Correct procedure as per the GM manual: LF, RF, LR, RR. You might be getting interference from the proportioning valve. I would gravity bleed all 4 for a couple hours then try the sequence. The bleeders must be closed on the pedal up stroke.

I am confused by this whole gravity bleed thing. What do you do, open all 4 bleeders with a tube running from each into a bottle sitting on the deck? I've never heard of this before, and it just isn't making my brain click, can someone explain to me how to do this and why it works?

The gravity procedure sort of gets all the lines expelling fluid and air at the same time. Fluid doesn't run out very fast, but you do need to top off the resevoir regularly during the procedure. The idea behind it is to get enough fluid in the lines so the proportioning valve won't be an issue. It still needs to be followed up with the individual wheel bleeding in the sequence I mentioned above. The GM sequence is almost backwards from what the Chilton's recommends.

What about using Silicon Break Fluid. Do you have to start with a clean system or can you just replace the old fluid by pushing it out with the silicon fluid?

With silicone brake fluid you have to start with a completely flushed, cleaned and dry system. Any moisture at all and trouble will occur. Silicone does not mix with water and aeration will occur, resulting in spongy brakes. Most, if not all high performance car manufacturers specifically state not to use DOT 5 (silicone) brake fluids.

DOT 5 fluids are best used for trailer queens and museum cars that don't get driven hard.

Gravity bleeding is very effective, but sometimes slow. I only open one at a time when gravity bleeding.

Dot 5 does not absorb water as Dot 3 does, so its nice for long term storage and little driving. It can work well in a normally driven road car. The post office truck use Dot 5.

The problem is Dot 5 has a lower boiling point than Dot3. So in high performance the fluid may boil and lose braking until it cools.
You must flush ALL!! of either fluid if you are going to use the other one. They are NOT compatible.

When I rebuild my braking system I am going to use Dot3, but I am going to flush the system every year so I don't get moisture problems.

i just replaced my RR caliper (damn thing was leaking and ruined the new paint on the inside of my rim ), I did an exchange up at "auto trash" and decided to try the speed bleeders (bleeders with check valves)...

they rock.. i found my self triple checking the damn things.. it was too easy..

best 8.99$ (for a package of two.. enough for one rear caliper) ive spent in a long time..

i just put the caliper on.. pumped the brakes 7 or 8 times.. got out.. looked at my tubing.. no air.. moved to the other bleeder it took 4 pumps to get no air..

this was the quickest i have ever bled one in my life..

I am in the middle of trying to get my pedal hard. I got a problem with my bleeder screws on my rear calipers. The inner bleed screws are seized up with rust and stripped for a wrench. Can I sucessfully bleed the brakes using only the outer bleed screws? I am bleeding the brakes untill the fluid turns clear and I see no bubbles. The rear pads are not very tight when the brake is depressed. That shouldnt happen right? Should I just swap out my rears because of the problems? My pedal is really soft. P.S. I did replace the master but was sure I bled it good before the install.

|UPDATED|6/3/2004 10:00:59 PM (AZT)|/UPDATED|

I'm not a brake expert, but if you can loosen up the frozen bleeders with a penetrating oil product you should be able to replace them. Heating them up would also be an option but that would probably mean removing the caliphers for easier (and safer) access.

As far as the pads being loose, there should be a spring behind each of the pistons to keep a slight amount of pressure on the pad. It is possible that one or more of the pistons could be stuck, or there could be springs missing, broken, or worn out which would mean less pressure on the pad. Disassembling the calipher, lightly honing out the cylinders, and installing new springs, o-rings, and pistons isn't too tough a job. Just a little time consuming. And then you get to bleed the entire system again...!!!

Tumarr said: The inner bleed screws are seized up with rust and stripped for a wrench. Can I sucessfully bleed the brakes using only the outer bleed screws?

sounds like the rear calipers are good candidates for a rebuild.. if the bleeders have been in one place long enough to rust in solid.. it is the safe thing to do.

when messing with the brakes ALWAYS take the safe route.

i agree with Norsky.. rebuild them rear calipers..