Can I Start The Car?

[NolliM3]

I did several work on my car (95 M3) including changing the clutch and clutch master cylinder. I have two problems, first: the passenger side brake line, I changed to stainless steel brake line and while connecting it to the hard line, the spring clip shifted as I was screwing it in, resulting in a thread on the hard line bending upwards. Second, the passenger side rear bleed nipple stuck in the caliper...I tried a tapered 7mm deep socket; however, that too stuck on the bleed nipple as it unable to seat down to the bottom on the nipple shaft. My plan to resolve is I have a straight 7mm 12point socket on the way...should get it in a day or two. Then, I'll try knocking off the tapered socket to see whether the 12point socket can remove it without me removing the caliper. For the brake line, I'll try bending the thread back to the original position with a knife blade then, run a rethreading tool nut (m10 * 1.0).

The car has no brake fluid in the reservoir...is it OK to start the car so I can bleed the cooling system? I know the brake system uses vacuum and that's my concern. Also, the 95 m3 doesn't require sinking the clutch pedal to start.

[bmwdirtracer]

Okay, let's start with the easy one: NEVER, EVER use a 12 pointed socket on a stuck six-sided nut or bolt. You must use a six-sided socket or wrench. I have no idea what a "tapered" socket is,,,,don't have any in my ~$70,000+ tool set. Sockets can only grab the hex part, never the shaft.

AND, you need to soak that bleed screw in PB Blaster, or Deep Creep, or LiquidTorque, at least overnight. Then, VERY gently, work it back and forth. An acetylene torch, professionally applied, might just help, although you'll certainly need serious bleeding of the smoked fluid afterwords.

It's probably going to break anyway - bleed screws, ESPECIALLY the old 7mm ones, do not like force. If it breaks, just buy a rebuilt caliper.

OR, bleed it at the hose connection.

Rethreading the line would be best done with a thread file or tap, not a pocket knife.

You need to keep fluid in the brake reservoir. If a brake line is open, cap it with a rubber vacuum cap, or the cap for the bleed screw. If the master cylinder runs dry, you'll likely have to take the car to a dealer or very well equipped independent BMW shop, to use a computer to bleed the ABS. Certainly, don't start the car and cycle the ABS without fluid in the master cylinder and reservoir.

[NolliM3]

Thank you Chris for responding...had hoped for your reply. Here is what I called tapered deep socket for lack of the correct term (attached screen shot). I have a rethreading nut as well as tap die set...the using the knife is only to straighten the bent thread just so I can run the rethreader. I am glad I asked before starting the car...I have DIS and had planned using that to bleeding the car. I had one of those caps that came with the stainless steel brake lines...it worked itself off letting out the fluid.

I did soak in PB Blaster; however, when it didn't loosen, I tapped the wrench with a small hammer and it rounded it...to make matters worst, I placed vice-grip on rounding it more. So, a friend said try the 7mm deep socket.

[bmwdirtracer]

Your only hope is a six point socket, of really good quality, or back to the vice grips. Bleed screws are extraordinarily weak anyway, and break in half, very easily, because they're hollow. At that point, I just order a rebuilt caliper, and let the rebuilding guys worry about drilling and retapping to a larger size...

[NolliM3]

Just a follow up and to say a big THANK YOU Chris...your recommended methodology (back and forth with PB Blaster soaking) worked like a charm on the stuck bleeder with this 7mm deep six point socket.

[bmwdirtracer]

Good job! Now that you got it loose, you might want to consider replacing it, because all the stress will have weakened it severely. You can actually swap a bleed screw without bleeding, because gravity will self-bleed it while you're doing it.

Did you need to use DIS ? Do you have a firm pedal now?

[NolliM3]

I still have that front passenger hard brake line screw to fix the buggered thread which I plan to tackle early in the morning (just too hot outside), and then I bleed with DIS. I changed all bleeders to the self-bleeder ones.