Originally Posted by drewactual
if the pads are almost gone, there is your reason for fade... the hydro doesn't have to move the calipers that far on new pads.. a 1/4" of shoe makes all the difference.. you could always put more fluid in to correct the fade, but that's just that much more you'll lose when bleeding them with the new pads and opening the calipers..
unless you've got a real good reason to be concerned about something tainting your fluid (as in your closed system isn't really closed) , I'd tell you straight up that draining and replacing fluid in a closed circuit system such as brakes is about as useful as changing the air in your tires.. now if there is something deteriorating to the point that the fluid is really whacky looking, it may serve you well to figure out what that is and fixing it when you do the pads... or you'll be changing your fluid again in another 50k miles or so..
I have to disagree with everything you have said.
Dark colored brake fluid is contaminated and needs to be flushed out. Old brake fluid is contaminated and needs to be flushed out even if it's not dark colored. Brake fluid absorbs moisture like a sponge. Moisture in brake fluid lowers it's boiling temp, takes away it's firmness which in turn causes delayed reaction. FYI..moisture can very easily get into a closed system so it doesn't need to be open to obtain moisture. It's called condensation! Adding more fluid does absolutely nothing because brake fluid relies on pressure. So, to say that the fluid doesn't go that far is true, but only because it's pressure that controls the calipers.
If you have contaminated fluid you def will notice a difference in pedal response regardlesss of how old or new your pads are!
Also, old fluid that conatins moisture creates rust inside your brake parts and is the main cause of caliper seizure and master cylinder problems!!!
I wouldn't use DOT3 if you plan to do a complete flush either. Go directly to DOT4 and use Synthetic fluid. Eitherway, use Synthetic. It's a much better and more advanced fluid than the cheapo stuff. It has a higher boiling point and is more responsive. (boiling point is critical in brake fluid as the temps can get extremely hot. Touch your rotors after a good city drive and see if the skin..if any is left...agree with this..haha, no don't do it, just trust me)
To do a simple bleed by yourself, get a one-man bleeder. They are like $6. You put the hose over the bleeder screw and stick the bleeder bladder up higher(they usually have a magnet to stick to your frame) Open the bleeder screw and begin to pump your brake pedal. Now, 2 things, DO NOT pump your brake pedal to the floor. Only pump 75% of the way or you can possibly cause damage to the seals inside the master cylinder if there's any sort of rust on the shaft(something you cannot see) the rust is there because obviously you never fully press your pedal down on a closed system so the surface rust is inevitable. 2. every 2 bladders you fill up, top off your brake fluid. i like to let the fluid go as low as possible so there's less mixing going on, but don't let air in the system or it may go into the ABS pump which is a pia to get out.
Start at the rear pass wheel, then driver rear, then pass front, the driver front. You'll want to go around the vehicle twice and on the second time, just fill the bladder only once. usually 5 pumps on the pedal fills it up, but check on your first fill to be sure. Also, make sure you colse the bleeder screw whenever you take off the bladder container to dump it out.
You shuld be able to flush your brake fluid for no more than $20.