1967 Rear Caliper Line: Armored?

[Owen L.]

My May '67 427 has non-armored steel rear caliper lines. I've long thought this was the proper design for the car but am now wondering if I had it wrong. The tech/judging guide (7th ed.), page 199, is all I came across:

A steel line is threaded into the fitting at the rear of the hose and curves upward and forward to enter the brake caliper from the rear.

That leads me to believe the non-armored caliper lines are correct — yes? I also seem to remember (and found a thread from 2015) that BB cars had armor while SB did not...

Thanks,
Owen

[Stephen L.]

Re: 1967 Rear Caliper Line: Armored?

My April 67 BB has armored lines at these locations.
Per the AIM, there is only 1 part number (left & right) for this item on page UPC 5 B2.
Therefore IMHO all cars had armored lines at this location, no matter the engine or brake options.

[Mark F.]

Armored Rear brake lines_001.jpg

[Owen L.]

Re: 1967 Rear Caliper Line: Armored?

Thank you Steve and Mark. I'll likely be doing a little brake work this spring and will change them out.

[Mark M.]

Re: 1967 Rear Caliper Line: Armored?

Cars with factory rear sway bars got the armored rear caliper line is what I've heard. A 1967 427 car I restored got no deducts for armored lines in NCRS or Bloomington.

[Joe L.]

Re: 1967 Rear Caliper Line: Armored?

Owen,

I agree with Steve.
The AIM even attempts to show the armoring with light slashes across the “pipe”.
Looks to me that there are are two parts numbers:
3879235 Left & 3879236 right

[ATTACH=CONFIG]120942[/ATTACH]

Mark------


I can say this: the part numbers for the rear brake pipe assemblies were the same for 1968-69 as for 1967 (GM #3872935 and 3872936). The original lines on my original owner 1969 were DEFINITELY NOT ARMORED.

However, my car is a small block. Big blocks used different brake line assemblies. These were GM #3879239 and 3879240. These were the armored lines.

None of the above-referenced lines were ever available from GM in SERVICE.

[Mark F.]

Re: 1967 Rear Caliper Line: Armored?

Mark------

I can say this: the part numbers for the rear brake pipe assemblies were the same for 1968-69 as for 1967 (GM #3872935 and 3872936). The original lines on my original owner 1969 were DEFINITELY NOT ARMORED.

Hi Joe,

Huh...I wonder what the difference was. '69 trailing arms and brake assemblies were essentially the same as '67, right ?
I'm not sure why the armoring was there anyhow.
I know it's a very sharp curve, but once properly formed (un-collapsed) it's hard for me to believe what could happen to them.
In fact, the armoring might have even caused acceleration of rusting.
They had a reason for doing it - and then they had a reason for not doing it in '69 - maybe we'll never know why...

[Stephen L.]

Re: 1967 Rear Caliper Line: Armored?

Joe, so is there a separate page entry in your '69 AIM showing distinct part#s for SB and BB brake lines at these locations?
If I read your reply correctly, the parts (xxxx935 & xxxx936) were changed to non armor and new part#s (xxxxx239 & xxxx240) indicated armor lines in 1968 or 1969...........

[Joe L.]

Re: 1967 Rear Caliper Line: Armored?

Joe, so is there a separate page entry in your '69 AIM showing distinct part#s for SB and BB brake lines at these locations?
If I read your reply correctly, the parts (xxxx935 & xxxx936) were changed to non armor and new part#s (xxxxx239 & xxxx240) indicated armor lines in 1968 or 1969...........

Stephen-----

No, what I am saying is that the '935' and '936' brake lines were ALWAYS unarmored and used for small blocks. The '939' and '940' were the armored lines but were only used for big blocks. Why the difference? I have no idea.

[Joe L.]

Re: 1967 Rear Caliper Line: Armored?

My May '67 427 has non-armored steel rear caliper lines. I've long thought this was the proper design for the car but am now wondering if I had it wrong. The tech/judging guide (7th ed.), page 199, is all I came across:



That leads me to believe the non-armored caliper lines are correct — yes? I also seem to remember (and found a thread from 2015) that BB cars had armor while SB did not...

Thanks,
Owen

Owen------


In my opinion, the fact that your car has non-armored rear brake lines means 1 of 3 things:

1) They've been replaced somewhere along the way. Unlikely if the lines appear "old";

2) St. Louis made a mistake and installed the small block lines on a big block. Very possible.

3) The car is not an original big block car. Do you ABSOLUTELY KNOW that the car is an original big block?

[Joe L.]

Re: 1967 Rear Caliper Line: Armored?

Hi Joe,

Huh...I wonder what the difference was. '69 trailing arms and brake assemblies were essentially the same as '67, right ?
I'm not sure why the armoring was there anyhow.
I know it's a very sharp curve, but once properly formed (un-collapsed) it's hard for me to believe what could happen to them.
In fact, the armoring might have even caused acceleration of rusting.
They had a reason for doing it - and then they had a reason for not doing it in '69 - maybe we'll never know why...

Mark-------

The1967 and 1969 trailing arms were the essentially same.

I am mystified that GM considered that small blocks could get by with non-armored trailing arms but big blocks required armored versions. I do not and never have understood why the armored lines were necessary at all.

The same 3879235/6 and 3879239/40 brake lines were used for 1966 through 1974. The 3879235/6 were then used from 1975-79.

[Owen L.]

Re: 1967 Rear Caliper Line: Armored?

Owen------


In my opinion, the fact that your car has non-armored rear brake lines means 1 of 3 things:

1) They've been replaced somewhere along the way. Unlikely if the lines appear "old";

2) St. Louis made a mistake and installed the small block lines on a big block. Very possible.

3) The car is not an original big block car. Do you ABSOLUTELY KNOW that the car is an original big block?

Joe,
1) I've owned the car since '79 and put on stainless lined calipers in the mid-'80s. I don't recall if I changed out the steel lines at that time or not, but am thinking I wouldn't have put on plain lines if the ones taken off were armored. (I've long been an originality nut!) Hard to tell "oldness", because there's not much difference in the appearance in 55-year-old lines vs. 40-year-old lines. They certainly could have been changed out by a previous owner in those 12 years before I bought it.

2) Why does the '67 AIM not call out the different parts for the big block over the standard installation? (My '72 AIM does not do this either.)

3) I am over 99% positive it's an original BB car. I personally pulled the tank sticker back about 1980, and have the Protect-O-Plate.


HMMM. What I though was a pretty straightforward Q and A has gotten fuzzy again. Is the bottom line that big blocks should more than likely have armored rear caliper pipes? Is this noted for the 8th edition of the judging manual?

[David D.]

Re: 1967 Rear Caliper Line: Armored?

There is a note in the 1967 AIM for the L36 and L71 engine options regarding Brake Lines. It states that (some components of) Brake Lines are different for the L36 and L71 RPOs, and refers you to the Parts List or Bill Of Materials to see the part numbers. I don't have access to the Parts List or BOM, but I suspect that is where we could find out if the rear brake pipes are different for the big block. Also, I suspect the armored rear brake pipe was specified due to the close proximity of the pipe to the rear sway bar bracket, as pictured on my car (excuse the dust, road grime, and weathered bushing .)


RR Brake Pipe Summary.JPGRR Brake Pipe photo reduced size.JPG

[David D.]

Re: 1967 Rear Caliper Line: Armored?

Here are enlarged versions of the two AIM sheet excerpts...

RR Brake Pipe Summary part 1 enlarged.JPG
RR Brake Pipe Summary part 2 enlarged.JPG

[Joe L.]

Re: 1967 Rear Caliper Line: Armored?

Here are enlarged versions of the two AIM sheet excerpts...

[ATTACH=CONFIG]120996[/ATTACH]
[ATTACH=CONFIG]120997[/ATTACH]

David-------

reason I
Yes, exactly. That information in the big block RPO's is part of the reason I provided the information I stated in my previous posts. Of course, we don't know, for sure, if these rear brake pipe assemblies are, in fact, the difference implied by the "brake lines" reference on the big block RPO's. However, I am virtually certain that these rear brake pipe assemblies are at least part of, and likely the only, brake line differences from standard configuration to big block.

1963-72 AIM's do not show just what the parts usage differences are between standard configuration and various RPO's. As you mention, they refer to "Bill of Materials" for that information. Of course, we do not have access to those documents. However, 1973 and later AIM's do have the parts difference information included in the standard pages of the AIM since these later editions do not have separate sections for RPO's. Sure enough, 1973-74 AIM's do have different rear brake pipe assemblies part numbers for small block versus big block options. In those editions, the part numbers for the standard configuration are the same as those shown in the 1966-72 AIM's. The part numbers for big block are as I mentioned previously. Considering the part numbers, I am virtually certain that the part numbers for 1966-72 big block rear brake pipe assemblies were the same and what we would find if we had the "Bill of Materials".

What we don't know, for sure, is which set of part numbers are the armored variety and which are the non-armored. As I mentioned, the original rear brake pipe assemblies on my small block 1969 were non-armored. That's for sure. But, it's possible it was a factory mistake. I could see how that could easily occur for these brake lines.

I would be very interested in hearing the rear brake pipe configurations (i.e armored versus non-armored) for other known original 66-82 Corvettes. I would be especially interested in the configuration for 1975-79 Corvettes since during those years there should have been no big block rear brake pipe assemblies at the St. Louis plant to use for a mistaken installation.