[njsteve]

It's always something! I have been ignoring the SD lately, with all the mechanical attention I have been paying to the Gramma Car.

I took the SD out for its first drive of the year and the rear brakes locked and wouldn't release. I had to crack both bleeder screws to release the pressure and get the car rolling again. I spent the afternoon removing the proportioning valve to send it to Whitepost for rebuilding. Shipped it off this morning. Luckily I had another valve from a 1972 to install in its place to keep everything from leaking out completely.

Whitepost had previously sleeved the original master cylinder and rear wheel cylinders a couple years ago. Hopefully this is the final component that needs attention, and not the master cylinder (again).

[njsteve]

Whitepost does fast work! Even though they said it would take three days, I had it back in my hands on Friday, after they got it Tuesday. So I guess they mean including shipping time as well!

Once I got it back I plugged the openings and let it sit out in the hot sun and soak, in a bowl of Evaporust, so the surface rust would wash away. This is how it looked after an hour or so. I then removed the plugs and used brake clean to make sure all the internal passages were free of any residue. It's interesting how you can see the "3 170" date code stamped on both sides.





As for the original rear brake hose, I had a hunch that this was the actual cause...and I was right. I removed it and attempted to blow air through the hose - nothing came out. It is completely swollen shut inside. So let that be a lesson on survivor cars with original brake hoses! They are not to be trusted! The swollen brake hose led to the proportioning valve being activated which then jammed in the activated position and wouldn't reset because the pressure differential wouldn't balance. So at least all the wheel cylinders, the master cylinder, and the proportioning valave are all internally rebuilt and work as originally designed now. I guess I will keep an eye on both fron brake hoses to see if they need to be swapped out in the future.






And the combination valve reinstalled and brakes bled. I took her for a test drive and the brakes work great again.