cann't get one of the front brakes to bleed

[chefplw]

I am at a lose. bought the right fluid(last ?) and a hand vacuum pump. took Terry's advice and try starting at farest wheel from MC. rear wheels bled easy. got to passenger side cant get it to bleed. tried other front bled easy. checked bleeder screw not clogged found pin hole in line. replaced still cannt get any fluid out. even tried manual bleeding( pumping pedal) no drop in fluid at MC. so dont think theres a leak. What should I check next. the brake on the problem front seems to lock when testing at 5mph and 3 or 4 pumps. thanks for any input. in case it matters 65 ex-mod 109 rhd

[Melissa Rose]

It may be your brake cylinder, Take your brake drum off and see if you can move the pistons in or out be careful not to pull the piston out.
Also you may have to re-adjust the brake adjuster which is on the brake backing plate it works on a cam.

[rovertek]

most likely a collapsed rubber brake hose, the pressure from the master forces the brake fluid through the hose past the collapsed spot but there is nothing to force it back through the other way so it will lock the brakes, remove hose and see if fluid drains.....