Brakes won't bleed

[Ranamok]

Hello all, this is my first time posting here. I'm thrilled to have found this site. I love my e30 and have had it as a daily driver for 6 years now. I recently replaced my pads with PBRs and started bleeding the brakes but the rear driver side caliper will not bleed. Passenger side bled fine but I haven't moved on to the fronts yet as I want to fix the rear first...
I've read a few forums but haven't found an answer to this. I've removed the bleeder screw and cleaned it. I've tried bleeding it without the bleed screw even, with no fluid at all coming out. I've even tried bleeding it with the engine running with no result. Odd thing is the caliper works. It stops the tire rotation with ease and lets go the second I take my foot off the brake. I have to conclude the lines are not clogged or swollen. I do intend on swapping the rubber lines with braided ones soon anyway but I'm thinking the caliper needs to be replaced? but why? What could go wrong inside a caliper to stop it from bleeding? Does anyone have advice regarding caliper rebuilt kits? They're cheap so I thought I would try that next...
Thanks!

[E30Gus]

Paper clip.
Shove it in there and then bleed.
The bleed holes get clogged. hahaha

Oh And welcome

[Ranamok]

Well, I did give the bleed screw the old paper clip cleaning, and I'm pretty sure I stuck it in the bleed screw hole as well but nothing happened. I'll give it another whirl. I really thought that pumping the brakes with the engine running would pop any clogs out of there though!
And thank you for the welcome :)

[Ceeker]

Well, I did give the bleed screw the old paper clip cleaning, and I'm pretty sure I stuck it in the bleed screw hole as well but nothing happened. I'll give it another whirl. I really thought that pumping the brakes with the engine running would pop any clogs out of there though!
And thank you for the welcome :)

Drain the reservoir; take an air line and blow air back through the bleeder hole. Make sure you have a buddy covering the cap so no excess fluid shoots out everywhere. That's the surest way to clear anything obstructing the line.

GL.

[Ranamok]

Thanks Ceeker. It'll be a few weeks until the air compressor arrives :( but I'll give it a whirl then if it's still giving me a hard time. I should get a little time with it this weekend.