[frank.g]

Nice article. While we often see coverage in the specialty mags for our cars, it is difficult to get into the mass market ones. It's great to finally see a car that I know in the likes of Hot Rod. Congratulations, Steve, Enrico, and the New, newer project, part tres.

[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.

[Held for Ransom]

Steve, did White Post stamp the WP or was that a coincidence?
The rear brake line collapsed on my '73 TA years ago too.

[njsteve]

Just coincidence. It was there before.

[Norwood]

Great work Steve. You have inspired me as I have been neglecting my brakes for years. I to have original everything other than the master. I will address all of this very soon. Nice work safety should always be a top priority.

[Uncle Judge]

Steve, I am very sorry to hear about your collapsed and swollen hose. Best of luck with the resurrection!

Sent from my XT1254 using Tapatalk

[77 Canamman]

http://www.ebay.com/itm/1970-1973-Pontiac-Firebird-rear-brake-hose-NOS-9755607-/331906021177?hash=item4d4723f739:gN0AAOSwv0tVDLu A&vxp=mtr

[njsteve]

Thanks for the link! I bought it. It is a more correct version than the one I installed. Excellent!

That takes some of the sadness out of having to remove my first original part on the car.

[njsteve]

Originally Posted by Uncle Judge

Steve, I am very sorry to hear about your collapsed and swollen hose. Best of luck with the resurrection!

Sent from my XT1254 using Tapatalk

A double dose of penicillin and brake fluid has cured it, Thank you.

[Norwood]

Isn't that nos a 40 year old part ?

[njsteve]

Yes but it's the contaminated 40+ year old fluid that kills the hose from the inside, not necessarily the age.

[Norwood]

Rubber doesn't deteriorate with age? I learn something new everyday.

[njsteve]

Uh Oh. Is the sarcasm light now illuminated? :-)

Well, not in the way that these hoses are prone to fail. My original hose looked perfect on the outside. Not a crack to be seen even when you bent it 180 degrees.... like a 19,000 mile example should look. (wait a minute now THAT didn't quite come out right). But inside it was a solid core of petrified goop. I guess also, being so close to the hot muffler probably doesn't help it either.

If you go back to earlier in my thread from a couple years ago, and look at the photos of the pistons inside the master cylinder you can see what contaminated 40-something year-old original fluid did. It dissolved holes in them!

This is definitely a prime example of why you should flush and replace your brake fluid every few years... or every four decades whether it needs it or not.

Anyone happen to know the original part numbers for the front hoses now?

[77 Canamman]

9753907 Discontinued 11/90.

[njsteve]

Thanks! Now the search begins for the front hoses.

[RAJ7395]

Don't get to excited. I fell for that e-bay sellers trap last year. Lists the right number in the ad but the actual hose you get is an incorrect #18002136 replacement. So.. It's NOS but not 40 years old.

[RAJ7395]

Most modern hydraulic hoses have an inner liner that is surrounded by reinforced (thread, steel wire, etc.) rubber. Once the liner becomes brittle due to age, exposure to elevated or arctic temperatures, repeated bending, etc. it will crack and allow the contained fluid to contact the rubber. Once this happens, the fluid will cause the rubber to swells up and eventually will work it's way into the reinforcement area and bulge the side of the hose resulting in failure.

[Bentwheelbob]

Originally Posted by njsteve

Just coincidence. It was there before.

Are you sure? My prop valve didn't have that stamp before going to White Post, but did after they rebuilt it. Same for the master cylinder.

[77 Canamman]

Originally Posted by RAJ7395

Don't get to excited. I fell for that e-bay sellers trap last year. Lists the right number in the ad but the actual hose you get is an incorrect #18002136 replacement. So.. It's NOS but not 40 years old.

That type of business practice is worthy of a bitch note and a negative feedback..

Hope Steve receives what is advertised...