Brake bleed question

cobra-6 · 02-29-2004, 06:32 PM

I installed an new master cylinder, all four brake hoses, and rebuilt the calipers. Bled the system 3 times with a power bleeder. Problem is the brake pedal still goes to the floor. I"m guessing there's air in the system but not seeing any when I bleed at the calipers. I also started the bleed process by cracking the attachments to the MC, and saw to bubbling. Any tips of what could be going on?. No leaks in the system that I can see. Is there a special M/C bleed technique?

CRNT918 · 02-29-2004, 08:16 PM

I would try bleeding with the aid of a helper. The force resulting from the push of the brake pedal will help to get trapped air out of the system much more quickly and positively than the power
bleeder can.

cgarr · cgarr's Garage

This is the same problem I had after rebuilding my calipers too. Those power bleeders just dont have the pressure to get all the air out, they work great to replace fluid, as CRNT918 said, get someone on the break and build some pressure.

Craig

Jim Chambers · 03-01-2004, 08:00 AM

This is unlikely but are all the bleed nipples at the top of the calipers? I once had a car that someone had switched calipers left to right on the front. Mounted fine but left the nipples down. Air rises and brakes would not bleed. Still can't figure out how they bled them. Problem only appeared when I took it to a pro to replace hoses. They spent several hours trying to bleed the system (and installed a new MC which I didn't need) before noticing the problem. A reputable Porsche shop too! They were embarrassed to say the least.

cobra-6 · 03-01-2004, 10:09 AM

I'll give the "old pedal push" way a try . Caliper nipples are all on top, so I can rule that out. It's seems a simple enough system, it's just hard to picture where the air is getting trapped.

Big D · 03-02-2004, 07:13 PM

Tried to use pressure bleeder to no avail. Used a 60cc syringe and pulled fluid through the lines with great success. DG

cobra-6 · 03-03-2004, 04:10 AM

What was your technique?. Did someone apply pedal pressure at the same time or did you just draw fluid until it was bubble free?.
Thanks

Big D · 03-03-2004, 08:08 PM

Left pedal alone. Changed fluid from crappy red to racing blue. Pulled fluid through lines until change of color without bubbles. Worked perfect. DG

dimps8 · dimps8's Garage

Always remember there's six bleed nipples. the fronts have one each on the outer halve of the caliper and the rears have two each. one on each halve. They all have to be bled. I found this out the long way.