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Brake Hardware kit general and specifics for 68

Started by DeVille68, September 22, 2014, 04:30:43 PM

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DeVille68

Hello everybody,


I am currently restoring my brakes on my 68 Caddy, after the front left brake lining failed and its rivets destroyed my original brake drum. I noticed that the springs were all color coded. These codes / colors are described in the service manual. I have not yet found a retailer that has the correct color codes for 68.

Here are the specifications of the service manual:
      
Front Drum Brake Hardware:                                      driver side color     passenger side color
Primary-to-secondary connecting spring                             yellow                      black                                          not interchangeable
hold down spring middle of primary shoe                           maroon                   maroon
hold down spring center of primary stabilizer plate            yellow                      yellow
hold down spring middle of secondary shoe                         blue                        blue
hold down spring center of secondary stabilizer plate        yellow                     yellow
primary retracting spring                                                      black                      black
secondary retracting spring                                                yellow                     yellow
      
      
      
Rear Drum Brake Hardware:                                   driver side color                  passenger side color
Primary-to-secondary connecting spring                           maroon                                      maroon                              identical
parking brake spring                                                         light blue                                     white                                not interchangeable
hold down spring middle of primary shoe                           maroon                                      maroon
hold down spring middle of secondary shoe                       blue                                             blue
primary retracting spring                                                     red                                              red
secondary retracting spring                                                yellow                                        yellow



Now I am wondering if these colors even have a meaning?
Do the colors encode the spring stiffness?
Or is it just to ease the installation?


From my engineering background I can almost for sure say that the brakes must be identical, so why do they explicitly write in the manual that "These springs are not interchangeable"


All kits that I have found so far contain identical springs for both sides....

Thanks a lot for your thoughts.

Best regard
Nicolas

1968 Cadillac DeVille Convertible (silver pine green)

Scot Minesinger

It seems like the springs should be good.  The ones on my 1970 Cadillac w/124k miles on it remain completely serviceable.  If you can't get the exact replacements, used springs could work.  Replacement springs from a kit may be reliable replacements.  Looking at the rear brakes it seems the spring colors may have been very helpful during assembly at the factory.  The primary differences between the springs are the lengths, size of coils, and connection hooks.  I would not worry too much about the colors.  The main thing is (I'm a mechanical engineer) is that the springs connect properly and serve their purpose as you know.  I just replaced my emergency brake cables and I should have photographed this set up so other s could see, but did not do that-sorry.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

"Cadillac Kid" Greg Surfas 15364

Nicholas,
If your original springs are not damaged or deformed you can re-use them. Regardless of the color replacement springs CAN be of questionable quality.
Greg Surfas
Cadillac Kid-Greg Surfas
Director Modified Chapter CLC
CLC #15364
66 Coupe deVille (now gone to the UK)
72 Eldo Cpe  (now cruising the sands in Quatar)
73 Coupe deVille
75 Coupe deElegance
76 Coupe deVille
79 Coupe de ville with "Paris" (pick up) option and 472 motor
514 inch motor now in '73-

cadillacmike68

The reason why some springs are not interchangeable from left to right are because they are shaped differently because of the direction in which the mount. Re-use your existing springs unless they are corroded.

Front and rear drums are interchangeable, just press in / out the hut for the front one. Better yet get it converted to front disc.
Regards,
"Cadillac" Mike

Scot Minesinger

Greg is so right on replacement parts quality.

The metallurgy treatment of springs, hardened parts and etc was far superior to parts manufactured today as replacements.  The collector car market replacement parts are made more for cosmetics in China.  Since proper heat treating, use of correct metals and etc. is not easily discovered/checked, they do not do it, resulting in fragile and inadequate parts.  Always go used when small obscure metal parts are required such as spring.  Of course China would get lynched if they did not use proper metallurgy on major engine parts.

Rubber is another item.  Rubber parts today are often of far lesser quality than the rubber used 40 years ago.  Some of the grommets I use to replace 40 year old ones, fail in three years.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Julien Abrahams

I did a brake job on my '67 a couple of months ago (replaced the shoes, hoses and fluid of the front system). I believe that the springs were not only color coded for convenience but they have different characterestics. If you look for example at the blue and the yelow ones, they have a different thickness and winding (= different tension).
I also used the old springs (as I simply was not able to find new ones) and I believe this works fine for springs.
1954 Cadillac series 62
1967 Cadillac Sedan De Ville HT
1969 Austin Healey Sprite
1979 Opel Kadett

DeVille68

Hi guys,

@Scot: Yes, you are right. I could probably count the number of coils and measure the length of the spring.

I added the notes from the service manual. Only the front Primary-to-secondary connecting spring and the rear parking brake springs are specifically marked as "not interchangeable"

My problem is, that I don't know if my springs are already reproductions or not. At least at some point some dude replaced the brake linings and had the stabilizer plate put back on wrongly. 
Also the link for the actuator lever was not properly bent allowing the star wheel to "spin" freely. That is what caused me all the troubles with my brakes.

I have attached pictures of my current set-up on the front.

So, which reseller?  Bendix? Raybestos?
See attached my little excel sheet where I compare the different suppliers.
To my surprise, there are no kits for the front drum??

1968 Cadillac DeVille Convertible (silver pine green)

DeVille68

Regarding brake hardware.

1) I still have not found any supplier of the correct front drum brake system. Can anyone help?

2) I ordered a brake kit for the rear. Contained almost all correct colored springs. Well the color is not so important but the stiffness should be. So I removed my old springs and expected to measure at least 10% to 20% more stiffness for the new springs. Because I assume that the age and harsh conditions will degrade the stiffness of the springs, well attached is a little table with my results.

3) So we can at least say that the springs have the same stiffness as my old ones. Only the rear secondary have double the stiffness (wrong measurement?).
Well, I don't know what the stiffness should be. But seams reasonable to me.

Any brake spring expert here?

4) I also measured the front secondary spring because it has the same diameters but it differs in the shape of the spring eye / or end. So you can not mount a rear secondary as an replacement for the front secondary!!! The stiffness would be about the same though.

Best regards,
Nicolas

1968 Cadillac DeVille Convertible (silver pine green)