82 Camaro, disc front, drum rear.

In the process of redoing my brakes, including replacing hard lines. I have the master cylinder in my vice, proportioning valve removed. The larger side of the reservoir has bled fine with no issues no bubbles. The smaller side of the reservoir however, when I pump it, it pushes an air bubble about halfway up my hose, and when releasing at any speed, it basically sucks the fluid and bubble backwards into the master cylinder output preventing me from getting the air bubble out.

I have manually filled the hose to that side, and have watched it suck the fluid back up without any pumping or anything. Just need clarification if this is something that warrants replacing the MC, or if this is normal behavior.

 

That's not right.

Replace it.

 

Will do. Also, super late on this, but Sofa, I wanted to thank you for saving me the cost of replacing my engine back in 2011!

https://www.thirdgen.org/forums/tech...ml#post4996394

It took me awhile, but I did it slow, took my time, and did twice the amount of work because the shop had actually told me the wrong cylinders and it was actually the passenger side that was blown. Ended up learning quite a few things in the process, like how to helicoil bolt hole 17 LOL.

Your words of advice have stuck with me for quite some time. "Don't worry, as you gain experience doing this sort of thing, you'll trust yourself more and more as time goes on." I feel they will stick with me for many more years to come.

 

Hey, you're welcome.

Glad to hear that even with the "shop" hiccup, it all worked out in the end.