Disc brake issue

[Johnl48]

I have a 4 wheel disc brake conversion on a 70 c20. After pressing the brake pedal and releasing i can't spin wheels freely, especially the fronts. I unbolted the master cylinder and it didn't free up the wheels so it's not the rod length. If I open the bleeders it frees up the wheels but still takes an effort to turn them. M/C is new with a hydroboost .
Any thoughts ?

[57taskforce]

Does it still have the drum brake residual pressure valves plumbed in the lines? They are basically small check valves in the lines that hold a small amount of pressure on the drum system wheel cylinder to keep the shoes on the drum and minimize brake pedal travel.

[litebulblsc]

Bad brake hose?

[Orange Crate]

sub'd

[Johnl48]

Originally Posted by 57taskforce

Does it still have the drum brake residual pressure valves plumbed in the lines? They are basically small check valves in the lines that hold a small amount of pressure on the drum system wheel cylinder to keep the shoes on the drum and minimize brake pedal travel.

No. All new stainless lines

[72c20customcamper]

When you open the bleeders on the front does it stream out or just a dribble ? If it streams out then I would think the master is defective since you unbolted it to check the rod and it didn’t help .

[Richard]

You mentioned new stainless hard lines. What about the hoses as litebulblsc mentioned? Old hoses can look fine on the outside while the inner liner has collapsed acting like a check valve.

[Johnl48]

Originally Posted by 72c20customcamper

When you open the bleeders on the front does it stream out or just a dribble ? If it streams out then I would think the master is defective since you unbolted it to check the rod and it didn’t help .

Hardly any fluid comes out

[72c20customcamper]

Originally Posted by Johnl48

Hardly any fluid comes out

Then it’s not a hydraulic problem . So it would stand to logic there is a mechanical issue. How long have the calipers been sitting ? May be hanging up .