My bet is the O ring is not in as good of shape than you think. Before you tighten down the screw put a little Vaseline on the threads and O ring. Helps things from cracking or getting stuck. When you tighten the screw you should feel the O ring start to engage and give some resistance. Then snug the screw up. But remeber a NEW O ring will engage sooner than an old one.

It's possible the Tee or the bleed screw could have a hairline crack in them(in the threads). Once the systems gets pressurized the crack expands and you are on the way to LEAK TOWN. Until you get a new bleed screw/ o ring, to see if the leak stops put some (like 2 wraps) Teflon plumbers tape on the screw threads. THIS is NOT a FIX just a test.


Good news is the solution is isolated to the Tee and Bleed Screw. Being able to fix this at home, and you are not broken down on the side of the road...I call that a WIN so far.

 

Interesting. How long have you been rocking that set-up?

 

6-8 years, 3 years and one is few months maybe. All of my disco have the same copper Tee replaced, The plastic crumbles within and some plastic parts might get inside your system.

 

I'm very tempted. Especially since I have to get to work in the morning haha Any downside? Also, what size copper T is that?

 

INDEED! Definitely a win

 

Not sure about the downside. If you have a cooling system problem, this is the least part that you have to worry. Like what I mentioned with my experience, the plastic crumbles in time and same as what you are experiencing now. Im not even sure if some plastic went inside my cooling system when that thing crumbled. The only overheating problem I had was hose and water pump leaks. I never had any issues even the babbling brook sound except when water is low because of leak. I think the size is 1 inch all around. While youre at Home Depot, go to the hammer isle and use the ball peen hammer to drive in to the ends so the lip will be a bit oversized. Though my other ones are still flat, no problems at all.

 

My plastic bleed screw was fine until it wasn't. Like yours, it wasn't obvious. Went to BMW, got the replacement plastic screw and it's been fine. Just be very gently with it and don't overtighten.

My research about the brass screw made me skeptical about the strength of the housing, but I like the copper tee approach. When bleeding the system I found that the bleed screw becomes a non-factor after the system warms up and is running, so not sure I would miss it for bleeding the system. Thoughts on that?

 

Yeah, the copper on the plastic T makes me a little nervous. I don't think I'd miss the bleed screw either, but Coolant Systems aren't my expertise. Wouldn't any air work itself out anyway? I too would love to hear everyone's opinions.

Also, as an update, it definitely was the screw. I threw some safety goggles on and took a close look, and the coolant was coming up right through the center of the screw (weird). Then, when taking it out again, crack... it breaks off. So now I have the bottom of the bleeder screw stuck in the T. At this point I'm pretty sold on just swapping the whole thing out for the copper T that LRN03NJ suggested.

 

I see this Tee at home depot, looks like the one...

https://www.homedepot.com/p/1-in-Cop...C611/100343973

Definitely makes sense to bang a lip onto the ends. Any other tips/advise before I dive into this? It looks like you added a few hose clamps along side the stock ones.

 

I like the copper tee for the steampunk look!