trying to solve solve soft brake pedal since weekend

[Uncle Gump]

Do you still have the speed bleeders?

 

[Curious Hound]

Yeah, That's what I was thinking too......pulling in air around the bleeder screw threads.
I might try some silicone grease, or just remove the boot and push the vinyl tube onto the bleeder.

The trick is to just barely crack the bleeder open. Just enough to get flow.

The threads are tapered like pipe threads. So the further you unscrew the bleeder, the more clearance there is to pull air through the threads.

The rubber nipple is fine. Remember, we're pulling a vacuum. So it's trying to suck the nipple tighter. It's fine.

 

[alwaysFlOoReD]

The trick is to just barely crack the bleeder open. Just enough to get flow.

The threads are tapered like pipe threads. So the further you unscrew the bleeder, the more clearance there is to pull air through the threads.

The rubber nipple is fine. Remember, we're pulling a vacuum. So it's trying to suck the nipple tighter. It's fine.

The bleeders I've seen may be pipe thread, but not tapered. There is a conical end that does the sealing.

 

[Uncle Gump]

I believe they're a straight thread with a tapered seat.

 

[Curious Hound]

I believe they're a straight thread with a tapered seat.

You're right. I was thinking about grease zerks.