4 wheel disks wont bleed :(

[No_Joke]

Alright I just bought this bug and it came with 4 wheels disks. The fronts are off a ghia and the rears are EMPI. It also has a new AC Industries dual circuit master cylinder. All parts were installed by the previous owner. I had to finish up the rear hard lines for the rear and now Im trying to bleed the system. The previous owner put in DOT 5 Synthetic fluid. I have to push the brake pedal like 5 or 6 times before pressure builds up and holds. Once I release the pedal and go to press it again, the pedal falls to the floor.

Do I need a residual valve due to the master being lower then all the calipers? Did the DOT 5 Synthetic fluid ruin the seals in the master? Im lost!!

[Bruce2]

You will know if the seals are compatible with DOT5 because if not, it will LEAK. Since you haven't noticed that, DOT5 isn't likely the cause.

Look at the whole system and identify where the high spots are. If the bleeder screws are way down low, take them off and swing them up so the bleeder is high. Put a piece of 3/8" metal or wood between the pads and bleed them like that.

You do not need a residual pressure valve.

[No_Joke]

Ya the bleeders are on the lowest part of the caliper. Im also trying to bleed the brakes using the vaccum method. Cant seem to get a good stream of brake fluid going.

[Jadewombat]

Alright I just bought this bug and it came with 4 wheels disks. The fronts are off a ghia and the rears are EMPI. It also has a new AC Industries dual circuit master cylinder. All parts were installed by the previous owner. I had to finish up the rear hard lines for the rear and now Im trying to bleed the system. The previous owner put in DOT 5 Synthetic fluid. I have to push the brake pedal like 5 or 6 times before pressure builds up and holds. Once I release the pedal and go to press it again, the pedal falls to the floor.

Do I need a residual valve due to the master being lower then all the calipers? Did the DOT 5 Synthetic fluid ruin the seals in the master? Im lost!!

You probably know this trick but get someone to help you. Pump it up quite a few times and hold it on the last one, have the other person crack a caliper open. Let the pedal only go halfway to the floor then have them close the bleeder. Do that a few times and most of the air should come out. Go onto the next caliper. Make sure you check the fluid level is good as you're bleeding.

After you do all of them, check the pedal again and do it a second round until you get all the air out.

Residual valves probably won't hurt either. Make sure all the DOT 5 is out of the system. DOT 3,4 and 5 don't mix.

[melville]

Ya the bleeders are on the lowest part of the caliper. Im also trying to bleed the brakes using the vaccum method. Cant seem to get a good stream of brake fluid going.

You've got an air bubble in the caliper above the bleeder, and you ain't getting rid of it until the bleeder is on the high spot of the caliper. Can you switch the calipers side to side? A little more work than what Bruce mentioned, but you'd only have to do it once.

[david58]

Ya the bleeders are on the lowest part of the caliper. Im also trying to bleed the brakes using the vaccum method. Cant seem to get a good stream of brake fluid going.

Sounds like the calipers are on the wrong sides. Can you post some pics of the calipers and lines installed?

[No_Joke]

You guys were right. The rear brake calipers were on the wrong sides (installed by revious owner) I switched them back around. And then for the front calipers i took them off and hung them up high to make the bleeder screw the highest part. I pressure bled the system and BAM now I have a hard pedal. Every once in a while I have to pump the brakes about 3/4 of travel to get a hard pedal again. Might need a residual valve? First time Iv ever owned a disk brake bug. I will never use drums again!! Bug stops on a dime and no pulls to left or right.. thanks guys!