sallydrive

I did a brake fluid flush on my system with the 2 person method starting from the resorvior, passenger rear, driver rear, passenger front, driver front. My brakes are still spongy and go down to the floor. What could the problem be? My car has 60K and covered with extended warentee.

mbeach

Spongy means there's still air in the system (air is compressible, so your pedal is soft then feels as if it "springs back" a little).
Pedal to the floor means there's a leak, somewhere.

I still believe that not cycling the ABS module leaves some old fluid in the system, but in this case, you might have some air trapped in there now.

Air could be trapped in pistons, the ABS module, or any place in your brake lines that is higher than your MC (I really haven't had time to dissect our braking system yet). My bet is that you ran into a little snag and sucked up some air on accident.

If you have the time (and the jack stands), get all 4 wheels off the car.
Add a length of tubing (get that clear 3/16 ID vinyl from Home Depot) to each brake caliper at the nipple. Make sure your hose is long enough to reach the ground.
Locate 4 clear and clean bottles. I use those Gatorade bottles with the plastic caps. Fill each bottle 1/2 full of new fluid and insert your hoses through a small hole poked in each cap. The ends of the hoses should be completely submerged in the new fluid.
Once you're set up, open each bleed nipple up a 1/2 turn or so (just enough to allow fluid to flow).
Remove your MC reservoir cap and press and hold your pedal a few times.
Then, this is important, leave it alone for a few hours.

Air will work its way up to the high point of your brake system on its own. The highest point should be your MC reservoir.

If you still insist on doing it yourself after correcting this, research a MityVac and the pressure bleeding technique. Not nearly as wasteful, and very thorough. I use my MityVac for nearly everything, including changing oil.

edgeucated

iTrader: (4)

yea, unfortunately if your brakes are still spongy, then there must still be air in them somewhere.

sallydrive

Thanks, and it sounds reasonable. I would like someone to verify this before I go and mess around with the system.

ChickenIS

iTrader: (1)

Your rear pads might be worn and contributing to this. I recently replaced the rear pads and the pedal became very firm. I did a brake fluid flush a few months ago.

06isDriver

ok so the problem likely lies in the fact that we have electronic actuators for the rear. You'll have to turn your ignition to on and depress the brake pedal (NOT ALL THE WAY) and hold it. Have someone at the rear open the valve and let the electronic actuator do its work for a very short time.

Do the fronts the manual way and this should ensure that all the air gets out of the abs modules and such.

I've got the same exact issue right now as I just replaced all rotors and painted the calipers, I'll be doing this procedure tonight.

mbeach

I don't see these actuators on the Sewell parts catalog.
Are you talking about the ABS module/manifold?

06isDriver

yes, the abs module. Sorry for the confusion

sallydrive

So someone has to be holding the break pedal while someone opens the valve? How long should this be done for and how many times?

mbeach

Wait, could you describe what you're calling the "two person method"?
I think we might have found your problem.

sallydrive

Someone presses and hold the pedal while the bleeder is opened and closed.

ISBU

While doing the flush, Did you happen to empty the brake cylinder reservoir? If so, you need to bleed the master cylinder first and do the rest after.

sallydrive

I took out most of the fluid..but not empty then filled it up to the top then started to flush it.