Brake fluid won't circulate from reservoir

[Deadwake]

Hey guys. I just bought a 1985 735i for $300 dollars and I'm pretty pleased with it so far, the guy thought it was going to be a lot of work to get up and running but it turns out the starter motor was just wired incorrectly. Anyway, I got new coolant, oil and brake fluid as I felt the previous owner probably didn't change those very often (The oil filter may of been factory.). I replaced the radiator hoses and coolant, changed the oil and filter and it was running sooooo much better, then I decided to do the brake fluid, I opened the passenger rear caliper and attached a brake bleed kit and started pumping my brakes, nasty, amber colored fluid was coming out.

I then checked my brake fluid reservoir and... the level hasn't changed. I use a towel to soak all the fluid out of the reservoir and find black crud at the bottom and possibly blocking the hose to the master cylinder, I clean it up as best I can and put new fluid it and try to pump, nothing. The reservoir level is staying the same and just air and tiny bits of fluid are coming out the rear caliper.

Any ideas what the problem could be or where I should start? Thanks!

[Jay535is]

COngrats on the purchasae, though I bet you are in for more than just a fluid change.
The reservoir should come off and you will probably find the holes at the top of the master cylinder clogged.
If they aren't clogged, then the bleeder on the calipers may be clogged. Unscrew the bleeder, and poke the hole with a small nail-I've had plenty of crud be stuck in a caliper.
The hose that leads down from the reservoir to the clutch master is about halfway up and shouldn't have much if anything floating to clog it-but all systems should probably be flushed if it sat for too long.
Good luck!

[DesktopDave]

Congrats! That's a deal, even if it does have a few little problems.

A few things come to mind. First off: is your car a manual? The E23 is unique for 80s BMWs, it has a completely separate hydraulic clutch, with a dedicated reservoir and short feed hose running into the cabin. The master cyl reservoir has no hoses, it's mounted directly on top of the master cyl.

Secondly, are you sure the brake bleeder kit is working properly? I've had a lot of trouble with vacuum kits, they tend to leak around the bleeder screw. The pressure bleeders have worked best for me.

Every brake system reservoir I've ever taken apart had some black sediment, I tend not to worry too much about it. I think it's just abraded rubber from the seal lips inside the master cyl or the reservoir sealing bungs.

[Deadwake]

Turns out, I'm just a moron, haha. It does indeed have a 5 speed manual transmission and I was looking at the reservoir for the clutch. Everything is good now!

[DesktopDave]

Meh, I've done dumber things myself. Glad it's fixed! How do the brakes feel now?

[Deadwake]

Honestly, not much better. Then again my other car is a Miata that can stop on a dime. I'm hoping it just has cheap pads and rotors and I can get some better ones when the pads go bad, they look fairly new, so for now I'll just hope that no one pulls in front of me.

I also noticed while I was down there that almost all my bushings and ball joints look to be in pretty bad shape, so I think I'm replacing those next.