brake bleeding issue, brake pedal hits the floor

[Simeon]

Here is a page from the fault finding section of this manual. This is from an earlier generation of ATE T50 remote boosters (actually fitted to Mercedes Benz) but the principles of operation are the same so the fault finding principles should be the same too. 

 

https://www.mb219.com/images/01_main/03_restoration/420_brakes/03_ate_t50_booster/ate-t50-power-brake-booster-manual-56-edition.pdf

 

[dlacey]

If the flex pipes are new and you have calipers locking on then the only possible reason is malfunctioning booster/servo..  

[dlacey]

Concerning the exact plumbing, it doesn't really matter as long as it's symmetric...one booster feeding top pistons and the the other feeding lower pistons....or vice versa...

[dlacey]

Concerning booster defects, if the brakes release when you crack open the booster inlet hydraulic line then it's a hydraulic seal problem or bore corrosion. If the brakes release when you disconnect the vacuum line the booster side of the check valve then it's a booster air valve leak. They are serviceable but seals difficult to get...they are available new from Continental for Mercedes applications but at 1500euro each you need  to be mad... There are aftermarket inline servos that will fit and work.

[Simeon]

14 hours ago, jdamm said:

ive pulled the pads out of the caliper in question then pumped the brakes to see if the pistons moved and they moved fine, however i didn't start the motor to see if they returned...

 

Just to be clear: The brake caliper pistons will not return on their own. They actually rely on slight run out of the brake rotor to knock the pads and pistons back in clear until they are compressed again by a brake application. If you pump them out, they will stay out and need to be carefully levered back inwards.