My Master Cylinder started dripping brake fluid from the line that goes from the Master Cylinder to the Metering Valve. It was leaking from the front nut that tightens the line to the Master Cylinder. I tried my best to tighten it without over-torquing but it still dripped. So I loosened the nut until it came all the way out, wiped it quickly to make sure there were no debris on the threads and then I retightened. ‘70 W-30 with front manual discs. The reservoir for the Master is about 1/2 full. Should I bleed the front brakes ?

 

Yes, if you broke a line loose you let air into the system.

 

X2...bleeding should be done,

 

Brakes should be bled every 5 years or sooner for a car that sits. Your daily drivers will benefit from frequent bleeding as well.

Brake fluid is very hydrophilic. Your brake system will live a long happy life with fresh fluid.

Don't use old fluid that's been sitting around. Always use fresh DOT 3. Don't store brake fluid in your shed or garage the Delta T will induce condensation.

Might as well replace the leaking line and all 3 rubber lines to the system. How old are those rubber lines?

Buy a "Motive" pump-style power bleeder. Makes one person bleeding a breeze.

Fill the master almost to the top. Allow some room for thermal expansion.

https://www.motiveproducts.com/colle...e-bleeder-kits

 

Mike, there is an easy alternative if the leak is caused by an imperfection in the flare or flare seating surface...

Buy some copper washers shaped and sized for the line size. Put this between the seat and the flare. Copper will crush and seal imperfections.

Here's an example for 3/16" line:
If it works, it will save you from forming a new line.

Gary

 

Not if the surgery was properly sutured.

 

Now that is funny Jaunty. I will say I replaced the master cylinder on my 75 Hust without bleeding the system. I certainly am not saying I recommend it but it worked for me. I bench bled the master cylinder and kept the bleeder hoses on when I put it on the car and took them off and immediately connect the brake lines. I have driven the car several thousand miles with no problems. In your case, I would say it is likely you got air in the system and bleeding is necessary.