Trouble bleeding...

[Just Scott]

First, I searched, read and tried most of the ideas...

Current condition:

New rear stainless soft lines (originals were highly constricted, maybe 1/16" ID)
Rebuilt (by me) rear calipers
Rear system from the T is completely empty
Bleeder screws are clean and aren't plugged

Master cylinder to reservoir seals replaced
Master never went dry, fluid was always over the piston

I've tried pressure bleeding (homemade version of the motive unit) and the two-person pump and hold method. I've tried pumping 12 times and then opening the bleeder. I've tried open, pump, hold, close, release countless times with no results.

NO fluid comes out of the rears. The reservoir level doesn't drop at all with pressure from the pump on the system and the rear bleed screws removed.

Somewhere, somehow the fluid isn't getting to the back.

Is there something about the car being on or with the ABS pump?

I didn't check the fronts yesterday, but will today. At this point, they are all original seals and lines (but all the rebuild parts and SST brakelines are here).

I don't have a vacuum pump, but will get one if that's the answer

Later today I will check:

Front brakes
Bleeder orifices in the calipers


Suggestions?

[jlevie]

If you aren't getting fluid out of either rear caliper, there is an obstruction in the fluid path. The first step would be to crack the line that goes from the ABS unit to the rear of car and see if fluid is released from there. If so the problem is between that point and the rear calipers. If not the problem is between that point and the master cylinder. In either case you crack connections from that point towards the end to find the obstruction.

[Just Scott]

Front calipers rebuilt and bleeding just fine.

Rear bleeder orifices are clear.

Starting crack plan.

[Just Scott]

Been cracking...

Good flow out of ABS unit
Good flow out of top of pressure regulator
Nothing out of the bottom of the pressure regulator with the system pressurized via Motive style pump or when I press the brake pedal to the floor

[Just Scott]

Took pressure regulator out - disassembled and cleaned brown goop out. Sprayed with carb cleaner and reassembled. Blew air through it and it seems to work.

While that was out, hooked up a hose to the rear brake line and blew those out. Good air flow from the engine bay out both rear calipers. Therefore, no blockages past the pressure regulator.

Re-installed brake pressure regulator.

Hooked up pressure cap to top of reservoir, set air compressor pressure reg at 15psi.

Pressurized system to 15 psi with bleeders removed and got....NOTHING

Pumped brake pedal and got....NOTHING

Started doing the open, pump, close, release and it felt better, but my wife's leg got tired and I got annoyed before we got anything out of the rear passenger bleeder.

Still in WTF mode.

Open to additional suggestions. The first one worked. Let's get another.

What I see as options:

1. More pumping
2. replace master
3. replace pressure regulator because cleaning isn't enough
4. vacuum pump - suck the fluid to the calipers

[bmwguy325is]

1. Find circle track boots.
2. Add more metal to bottom (preferably brake pads)
3. Cut whole in floor.
4. Say Yabba dabba doo

[jlevie]

See post #2 to find the problem.

[Just Scott]

1. Find circle track boots.
2. Add more metal to bottom (preferably brake pads)
3. Cut whole in floor.
4. Say Yabba dabba doo

So, to make this work, I'd need to cut the holes in the rear seat pan to maintain brake balance?

[Just Scott]

Several people suggested patience and gravity bleeding...

Those people were right. I let the rears gravity bleed overnight and had a nice puddle on the passenger side. Tonight I opened the driver's side and put the pressure cap on it. Got a puddle almost immediately.

Buttoned that up and cleaned up the mess.

I'll do an open, press, hold, close, release bleed job next. A few high speed stomps. Another bleed and should be good to go!

BTW, don't buy one of those rear brake pressure regulators. Take it apart and clean it out. If it's leaking, replace the O-rings. Probably have to get those from McMaster or Motion Ind though.

[lcoleman]

For the record, it's press, hold, open, close.

A little known fact is that with ABS, you can open, pump (a bunch), and then close. The valves in the ABS unit will keep air from being pulled back into the calipers.

[Just Scott]

Really appreciate the advice...

The gravity bleed worked. The press, hold, open, close worked.

I have brakes again.

Now to put the rest back together and drive the thing. Should be Saturday afternoon.

[carfantiti]

crap thought this was about hemroids or your period never mind.
remove your brake reservoir and see if any rubber chunks residue is clogged in bottom.