moonrunner1972
Active Member
- Joined
- Mar 14, 2011
- Messages
- 231
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- 22
Folks, I turn to you for advice for my brake problem. After replacing the calipers and brake pads on my 1973 Dodge Polara, I found a great deal of rust and corrosion inside the master cylinder from contaminated brake fluid. Since a rebuilt unit from Auto Zone cost less than $30, I figured it would be money well spent and opted for a replacement. After bench bleeding the new part, I bolted the master cylinder up to the power booster and threaded the lines into the ports. Initially, the fittings went in without issue, but didn't seem to thread in as much as on the old part. I should mention that the exposed threads were a bit rusty so I carefully hand threaded the lines in until a wrench was necessary to install them the remainder of the way.
After cracking the bleeder screw on the left front brake caliper, with a rubber hose secured to a bottle of brake fluid below a few inches of clean fluid I began to slowly pump the brake pedal to bleed the air out of the lines. I quickly discovered that the line for the rear brakes (front reservoir) was leaking. Assuming that it was not tight enough, I tightened the line as much as I could, yet I noticed that the line itself could move back and forth inside the threaded fitting.
After several failed attempts at removing and replacing the fitting from the master cylinder, the leak remains. Has this happened to anyone before when using a rebuilt master cylinder? At this point, I am under the impression that the combination of the rust on the threaded fitting as well as the threads inside the port are preventing the fitting from seating properly. Aside from using a small wire wheel on a Dremel to clean the threads on the line, I can think of no other way to solve the problem. I had considered using a tap on the port and running a die over the threads of the fitting, but I am unsure of the exact size. The rebuilt master cylinder came with an adapter that threads into the port I have referenced and will accept the threaded fitting of the brake line. The thread pitch is 18 and the size appears to be 1/2". Can anyone verify the accuracy of this final statement? Thanks in advance, I always appreciate the feedback.
:sFl_america2:
After cracking the bleeder screw on the left front brake caliper, with a rubber hose secured to a bottle of brake fluid below a few inches of clean fluid I began to slowly pump the brake pedal to bleed the air out of the lines. I quickly discovered that the line for the rear brakes (front reservoir) was leaking. Assuming that it was not tight enough, I tightened the line as much as I could, yet I noticed that the line itself could move back and forth inside the threaded fitting.
After several failed attempts at removing and replacing the fitting from the master cylinder, the leak remains. Has this happened to anyone before when using a rebuilt master cylinder? At this point, I am under the impression that the combination of the rust on the threaded fitting as well as the threads inside the port are preventing the fitting from seating properly. Aside from using a small wire wheel on a Dremel to clean the threads on the line, I can think of no other way to solve the problem. I had considered using a tap on the port and running a die over the threads of the fitting, but I am unsure of the exact size. The rebuilt master cylinder came with an adapter that threads into the port I have referenced and will accept the threaded fitting of the brake line. The thread pitch is 18 and the size appears to be 1/2". Can anyone verify the accuracy of this final statement? Thanks in advance, I always appreciate the feedback.
:sFl_america2:
