Chasing a firm brake pedal, What next? Options

[robkammer]

Teeners: It's been over two years since our 74 BB arrived. A Caliper blew out as it came off the transporter in 12 degree temps. Really no surprise as the PPI pointed out a leaky caliper. So I did what I thought would be appropriate for this little beauty, I sent all of the hard bits out, calipers and regulator, to a widely recognized firm for 'restoration'. Put in a new EZ master from 914. And all should have been fine. But, even now, after 1800 miles, a second set of calipers from the 'restorer', a new ATE MC from the restorer. ( I threw out the EZ MC). I still have squishy pedal.
I do not suspect the pedal box area as the car has absolutely no rust.
I just rebuilt the 'restored' front calipers with new square cuts from AA, took out the springy metal pieces that are supposed to keep the pistons from rotating, and the pedal is much better. I have about 50 miles on this but after bleeding it again the bleeders were leaking and I put it back on the lift. ( I was told: maybe: we left the calipers in the acid too long)
So: Now that the pedal seems like I might be on my way to GOOD braking, I can hear the pressure regulator knocking when I press the pedal, at a standstill, in the shop. Is this normal and to be expected? Note: During attempts to bed the brakes and get them working, I was only ever to lock up the rears, and it was really difficult to do. ( difficult may not be accurate, violent might be more appropriate)
The newly rebuilt calipers seem fine, just like the calipers in my 911's that I rebuilt.
As for bleeding, I've done it every way known to man. And some new ones too. Just picked up a 6th quart of Super 4. $26.00!!! A fifth of Weller was only $23!.
I'm really frustrated with this little car. Any input will be appreciated.

I'm thinking of putting in a Tee in place of the regulator, just for testing. If anyone has a Tee that they would be willing to let me borrow, I would be willing pick up all of the shipping just so I don't have to mess with the fab work.
Thanks,

[Superhawk996]

I can hear the pressure regulator knocking when I press the pedal, at a standstill, in the shop. Is this normal and to be expected?

Yes - normal to hear the piston in the regulator move with the engine off and in a quiet environment.

Do not replace with a T - you’ll just set yourself back and introduce more air into the system again. The regulator has absolutely zero proportioning effect upon the front brakes. It only reduces the rear pressure in proportion to the fronts.

You do not want to lock the rear brakes before the front - ever! Focus on getting the air out of the front brakes.

Stop using $26/quart brake fluid while you’re working on getting air out of the system. Once you have a good pedal feel you can bleed out - replace with expensive fluid if that’s what you desire.

Don’t underestimate pedal box flex. A reinforcement bracket is not necessary to be able to lock the front brakes when bled properly but these cars all had flex that degraded pedal feel when they were young and none have improved with age, rust, and metal fatigue . Tangerine makes a nice bracket to reduce the flex.

Leaking bleeders isn’t right. If they aren’t tight you’re letting air into the system as well as losing fluid. If they are tightened properly and still leaking, I’d be returning them to whoever rebuilt them - not sure what to make of the acid comment (IMG:style_emoticons/default/unsure.gif)