Emergency brake cable routing sanity check

The forum for all of your technical questions on your classic FIAT autos
kgfiske
Posts: 46
Joined: Sat Nov 11, 2017 8:47 am
Last Name: Fiske
First Name: Kelly

Emergency brake cable routing sanity check

Post by kgfiske » Mon Jun 10, 2019 1:14 pm

OK folks, I need a sanity check on the routing of the E brake cable on the 79 and later Spiders. Over this past weekend, I was working under my recently acquired 82 Turbo Spider and noticed something odd (at least to me) on the routing of the emergency brake cable. On the passenger (right) side of the car, the cable routes OVER the long trailing arm, which seems to be taking the straightest path to the rear caliper. However, on the driver (left) side of the car, the cable routes UNDER the long trailing arm in a not quite as straight path. I have looked for pictures of the rear suspension/brake cable routing in the owners and service manuals, but cannot find anything conclusive on how they were originally assembled. I should note that the emergency brake cable on my car was recently replaced by the prior owner.

Hence my question: Is this the way they were assembled at the factory? If so, any logic in why they did it this way?

Thanks!
Kelly Fiske
Akron, OH
78 Spider
82 Spider Turbo
User avatar
18Fiatsandcounting
Posts: 75
Joined: Tue Apr 16, 2019 8:47 pm
Last Name: Balazs
First Name: Bryan

Re: Emergency brake cable routing sanity check

Post by 18Fiatsandcounting » Mon Jun 10, 2019 2:00 pm

Well, my reply may end up confusing things even more, but here goes: On my '69 spider, the emergency brake cable goes over the trailing arm on the passenger side and under the trailing arm on the drivers side. On my '71 spider, the cable goes under the trailing arm on both sides. However, in all cases, the cable is routed under/beside a metal tab welded to the trailing arm, presumably installed to help guide the cable as there's nothing else in that vicinity. This tab is pointed down from the trailing arm on both sides of the '71 and the drivers side of the '69, and pointed up on the passenger side of the '69. If your car has such a metal tab (about 1.5 inches), then my guess is that would be the side where the cable should be routed.

I believe my '71 to be original, and I did have the rear axle rebuilt on the '69 so that may be why it is reversed from one side to the other as the repair guy could have installed one of the trailing arms upside down. As to which side (below or above) is better? On both my cars, the lower route would appear to be the most direct. Your '82 may be different.

Here's hoping someone with more definitive knowledge than my conflicting anecdotes can weigh in... :)

-Bryan
User avatar
atruscott
Posts: 577
Joined: Sat Mar 19, 2016 10:40 pm
Last Name: Truscott
First Name: Andy

Re: Emergency brake cable routing sanity check

Post by atruscott » Mon Jun 10, 2019 3:25 pm

Over the years there have been a few different types of long arms, with different "tabs" to assist the routing of the e-brake cable. Not just the 1.5" rectangular tabs, but also a round tab with two "arms" that holds the rubber fitting on the cable.

Looking in the manual you get the image below... clearly showing the tab on the bottom of the left hand arm. I couldn't find an image of the right hand arm.

However, the tab isn't in the middle of the arm, so there's only one way around to put the arm.

Thinking about this..... As the car drives along and the arms move up and down, they're going to put different levels of strain on the cable. But, as the cable is in a metal horseshoe where it attached to the brake lever, and if it has one cable above and one below the arms - then the effective tension on the cable should stay constant.

If they both routed above the arm, then under heavy load, the cable would effectively have further to run and would put tension on the rear brakes. The same with the cables being routed under the arms and the car coming over the brow of a hill at speed....

Maybe this is actually a really super smart design?

Andy
Attachments
Capture.JPG
Capture.JPG (23.56 KiB) Viewed 568 times
1960 Autobianchi Bianchina Transformabile
1970 238 Camper OHV
1974 124 Wagon TC
1974 124 Special TC
1975 124 Sport Coupe
1976 124 Sport Spider (The Racer)
1981 Spider 2000 (The Resurrected)
1985 Pininfarina Azzurra
2017 124 Spider Abarth Elaborazione
kgfiske
Posts: 46
Joined: Sat Nov 11, 2017 8:47 am
Last Name: Fiske
First Name: Kelly

Re: Emergency brake cable routing sanity check

Post by kgfiske » Mon Jun 10, 2019 3:58 pm

Both of my control arms have the tabs. The drivers side faces down and the passenger side faces up. Not to say one could have been flipped.
Kelly Fiske
Akron, OH
78 Spider
82 Spider Turbo
User avatar
18Fiatsandcounting
Posts: 75
Joined: Tue Apr 16, 2019 8:47 pm
Last Name: Balazs
First Name: Bryan

Re: Emergency brake cable routing sanity check

Post by 18Fiatsandcounting » Mon Jun 10, 2019 4:06 pm

Andy might be on to something here, and I have to admit to not really noticing this before. I suppose one could test this theory about the alternating under/lower routing by jacking up the rear of the car (by the body, so that the axle is hanging down), and then seeing if the handbrake lever feels like it engages sooner or the same and, if one is so inclined, putting something heavy in the trunk (sand, cement, St. Bernard, spouse :shock: ), and then seeing how the handbrake lever feels. In either case, if the brake cable housing appears to be really taut against the trailing arm with no "give" when the handbrake is released, then it may not be routed correctly.

-Bryan
User avatar
bartigue
seimila club
Posts: 6195
Joined: Sat Jan 23, 2016 11:49 pm
Last Name: Artigue
First Name: Bradley
Contact:

Re: Emergency brake cable routing sanity check

Post by bartigue » Mon Jun 10, 2019 5:07 pm

I believe that the proper routing is below the arm, though diagrams in the 75-85 manuals will show it above:


Above:
Page 44-19 of the service manual (75-82 and 83-85 manuals) show both cables routed above the arms (diagram)
Page 33-3 of the service manual (75-82 and 83-85 manuals) show both cables routed above the arms (diagram)

Below:
Table IIIf of the 1975 supplement shows the brackets under the arm (diagram)
Page 3 of the owner's manual (1966) shows both cables routed under the arms as does page 25 (photo and diagram)
Page 52 of the steering and suspension manual for the "spidereuropa" show the brackets under the arms (diagram)


My 1969 and 1982 have the cable routed below, though some numbnuts also routed the driver's side on the 69 so as to avoid the arm altogether. This is on a car with no front brakes at all, so go figure.

I find that, when mounted incorrectly, the cable will be bent in such a way as to strike the exhaust.
-----------------------------------------------------------
Brad Artigue
1969, 1969, 1970, 1979, 1980, 1981, 1982, and 1982 124 Spiders
1969, 1970 850 Spiders
77 X1/9
http://fiat.artigue.com
User avatar
atruscott
Posts: 577
Joined: Sat Mar 19, 2016 10:40 pm
Last Name: Truscott
First Name: Andy

Re: Emergency brake cable routing sanity check

Post by atruscott » Tue Jun 11, 2019 9:29 am

The tabs are at an angle, so the long arms only fit correctly one way around.... which means one is up and one is down on the two arms.

That said - this might all be hoodwinking by our vendors who've only got a single part produced :)
1960 Autobianchi Bianchina Transformabile
1970 238 Camper OHV
1974 124 Wagon TC
1974 124 Special TC
1975 124 Sport Coupe
1976 124 Sport Spider (The Racer)
1981 Spider 2000 (The Resurrected)
1985 Pininfarina Azzurra
2017 124 Spider Abarth Elaborazione
kgfiske
Posts: 46
Joined: Sat Nov 11, 2017 8:47 am
Last Name: Fiske
First Name: Kelly

Re: Emergency brake cable routing sanity check

Post by kgfiske » Tue Jun 11, 2019 12:15 pm

You are right, there is absolutely no other way the trailing arms can be positioned with the angled tabs. So, I'll conclude that is the way they configured the set-up on the later models. Logical? Who knows...
Kelly Fiske
Akron, OH
78 Spider
82 Spider Turbo
User avatar
MikeGreer
Posts: 82
Joined: Sat Aug 25, 2018 2:37 pm
Last Name: Greer
First Name: Mike

Re: Emergency brake cable routing sanity check

Post by MikeGreer » Sat Jun 15, 2019 7:08 pm

I have two additional manuals besides the '75-'82 factory manual, one published by Drake the other a Haynes. Both show the cable on the underside of the trailing arms on both sides. The Haynes is an illustration, the Drake looks more like a photo.
Attachments
IMG_0113.JPG
IMG_0113.JPG (1.67 MiB) Viewed 420 times
IMG_0112.JPG
IMG_0112.JPG (1.35 MiB) Viewed 420 times
45 years with a spider, that's a long time
Restoring the '79 for the second time, you're never finished ;)
User avatar
bartigue
seimila club
Posts: 6195
Joined: Sat Jan 23, 2016 11:49 pm
Last Name: Artigue
First Name: Bradley
Contact:

Re: Emergency brake cable routing sanity check

Post by bartigue » Sat Jun 15, 2019 9:19 pm

I may have found the definitive, indisputable answer. The homologation paperwork for the 124 Spider (in the library) has a picture of the rear suspension clearly showing the cables routing under the bars.
-----------------------------------------------------------
Brad Artigue
1969, 1969, 1970, 1979, 1980, 1981, 1982, and 1982 124 Spiders
1969, 1970 850 Spiders
77 X1/9
http://fiat.artigue.com
Post Reply

Who is online

Users browsing this forum: No registered users and 17 guests