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nlorntson Tue Dec 07, 2010 10:11 pm

Some of us have cars with cable brakes so I though it might be good to make a post with some of the details about the parts of the system, adjustment and maintenance.

The whole system:



Below is a diagram of some of the parts in the tunnel. This is from the 1950 spare parts book


Below are all the pieces of the front end of the brake setup. On top is the hand brake rod, the fine adjustment pin, the cable end retainer, a small spring plate retainer to keep tension on the hand brake when the foot brake is applied, and a cotter pin to hold it all together. At the bottom is the foot brake actuating rod.




Below is a shot of the foot pedal push bar and the spring arch that supports and puts tension on the hand brake rod as it runs at an angle down from the hand brake lever to the framehead.


Another view



This is the front end of the foot brake rod. It is flipped over to show the bottom where hook that the tension spring attaches to. The other end of the spring attaches to a tab inside the frame head. It's a bit tricky to get it reattached inside, especially if the body is on the chassis.



Below is a picture of the back end of the foot brake rod where the brake pedal connects to it. The two pieces are separated a bit to show the thicker welded on piece the pedal lug pushes on whe the pedal is pushed.



Below is a shot looking towards the front of the car of the foot brake rod and the pedal cluster



This is the brake light switch. Pressing the foot or hand brake pushes both rods forward and removes tension on the switch and closes the circut.



Below is a shot of the frame head where all four cable ends are ready to hook into the front of the foot brake rod. In the center of the four cable ends is the tensioner spring that attaches to the hook on the bottom of the foot brake rod seen above.



Below is the rear end of the hand brake actuator rod. The end of the hand brake slips into the groove and the ball end presses against a solid plug inside the rod where you see the rod narrowing. The slit in the hand brake rod just serves to center the hand brake.


Below is the foot brake and hand brake rods assembled and inserted in the frame tunnel, the cable ends are in the retainers and the spring is attached. The square pin in the center is the fine adjustment for the hand brake rod


Below is a shot at the left side of the assembly near where the brake switch will mount.


Below is the finished assembly


Here is the brake switch installed


Here is the whole works.



The bigger bolts and washers on the sides are what hold the cover on. The cover is very similar to the early hydraulic brake setup, but there is a notch for the wires to the brake switch. The early 49 cars had no rubber gasket between the cover and the frame head.


The next installment will be information about the wheel end of things.

maesdieter Wed Dec 08, 2010 1:16 am

Very nice, i now see what i am still missing at the front. Once a brakecable pops out at the front, and the brakes did not release...
Dieter

79SuperVert Wed Dec 08, 2010 6:46 am

Thanks for posting this info. I've always been interested in how the mechanical brakes work. Who knows, maybe one day I'll have a car with them! :D

Blue Baron Wed Dec 08, 2010 10:58 am

I always wondered why the clutch cable was so blasted hard to feed into the tube in my oval, and why the tube was way over on the right side of the tunnel. Now I know. It's because the actuator parts for the mechanical brakes took up the space in between.


Brezelwerks Wed Dec 08, 2010 12:17 pm

Very nice review, would be nice if this info could be archived or be made a sticky here.

nlorntson Wed Dec 08, 2010 12:21 pm

Spare parts diagram from 1950



Below are the pieces of the brake components seen at all four wheels. There is no independent emergency brake connection since the hand brake just pushes on a rod that actuates the brakes on all four wheels.



Below are the components all cleaned up. At the top is the special adjustment screw. Just below that is the adjustment cam this screws into from the back (seen at the 11 o'clock position above). The back of this piece is tapered so as the bolt is tightened from the back, it is drawn into the cup and it pushes on the adjustment pins forcing the shoes out. You can see a cotter pin runs through the center to keep this piece in the cup.

Arrows point to the next two pictures



Below, you can see there are two different lengths for the adjusting pins. Anyone know why? These are oriented so the tapered cam mentioned above pushes them out.



The bolt that screws into the adjustment cam from the back is a special bolt with tiny lugs on the bottom surface. These mesh with similar grooves on the backing plate and serve to lock the bolt in place after adjusting the brakes.



Below you can see the backing plate and the adjustment for the cable as it enters the backing plate. Brake adjustment is basically done by screwing out the top piece so it puts pressure on the cable as it enters the wheel. The locking nut is tightened against the adjustment cone. you can see the special bolt mentioned above in the background.



The cable enters the backing plate and attaches to this assembly. As tension is put on the cable by the foot or handbrake, the cable pulls on this piece and it acts as a lever to push the shoes apart and apply the brake.


This is a better shot of how this assembly actuates the shoes.


The adjustment procedure is as follows:

Adjustment

1. Lift the car and release the hand brake.

2. Check the clearance between the handbrake push bar and the foot brake push bar (approximately 0.04) at the handbrake lever. If necessary, adjust the handbrake push bar. You do this by removing the tiny cotter pin and spring plate at the front and screwing the fine adjustment pin in or out as needed. Basically the hand brake should not be putting any pressure on the foot brake.



3. Eliminate the free movement of the brake pedal by correcting the position of the stop plate.

4. Start at any wheel. Release the adjusting sleeve locknut at the backing plate where the cable enters.

5. Turn the adjusting sleeve and locknut clockwise, that is, towards the brake back plate. Tighten the brake shoe adjusting bolt until the brake drum can no longer be turned by hand. If the wheel has just been installed, turn the adjusting bolt until a heavy drag is felt.

6. Turn the adjusting sleeve out, away from the backing plate until there is very little clearance between the end piece of the cable and the adjusting sleeve. Tighten the adjusting sleeve locknut against the sleeve.

7. Loosen the brake shoe adjusting bolt until the brake drum can be turned freely. A light tap against the bolt will place the brake shoes and the adjuster cone in the correct position and seat the little bumps into the notches on the backing plate.

8. Repeat on the other wheels.

9. Pull up the handbrake by three notches and check equal braking effect on all four wheels. In case there is a difference in the braking effect among the four wheels, release the handbrake and loosen the brake shoe adjusting screw on the wheel with the highest braking resistance. At the fourth notch on the handbrake it should be impossible to turn the wheels by hand.

10. Lower the car and make a road test to ensure proper brake operation.

11. After road test re-check the brakes as follows:

12. Lift the car and release the handbrake.
Tighten the brake shoe adjusting bolts of all four wheels until the brake drums can still be turned freely.

13. Pull up the handbrake by three notches and check equal braking effect on all four wheels. In case there is a difference in the braking effect among the four wheels, release the handbrake and loosen the brake shoe adjusting screw on the wheel with the highest resistance. At the fourth notch on the handbrake it should be impossible to turn the wheels by hand.

14. Lower the car and make a road test to ensure proper brake operation.

johnshenry Wed Dec 08, 2010 1:14 pm

Wow, great stuff Nancy, thanks for poisting. I am fortunate to have all the cable brake parts for my '51 std. I have to figure out how to get the TONS of grease out of the tunnel head before sending the chassis to the media blaster.

Common problem was mechanics "pushed" grease in from the zerk fittings at the ends of the cables (at the wheels) and didn't pay attention to how much was coming out of the front (although the theory is that you were supposed to push all of the "old" grease out at service intervals).

And if you didn't take the framehead cover off, all of that grease just got pushed back into the tunnel.....!!

cancunsplit51 Sat Jan 22, 2011 9:08 pm

: i just bought a split window delux 1951, but unfurtunately its missing the whole brake system, can somebody tell me where to find it, i have checked some sites and companies, and havent been lucky finding it......

nlorntson Sat Jan 22, 2011 9:29 pm

If its got cable brakes, good luck. The only source I konw of is the classifieds on this site. If you need hydraulic brakes, those parts are readily available in the classifieds as well as new at places like wolfsburg west, cip1, vintage parts, and others.

johan_l Sun Jan 23, 2011 3:02 am

These type of posts is great, not that I have the mech-breaks but I like to see how they look. Really good description an pictures! :) This is what is great with thesamba and the members!

Harris Mon Jan 24, 2011 6:45 am

Quote: These type of posts is great, not that I have the mech-breaks but I like to see how they look. Really good description an pictures! This is what is great with thesamba and the members!


X2 here. Super post.

nlorntson Mon Jan 24, 2011 7:00 am

Thanks fellas.

Even I found it useful the other day as a place I could go to quickly reference something without digging through a book :oops:

Nancy

VWKDF Fri Dec 28, 2012 9:33 am

I was just checking this thread out as I am working on a cable brake chassis at this time and I thought a nice addition to all the information here would be the date of the last cable brake VW, anyone know?

Grant Reiling Fri Dec 28, 2012 2:43 pm

Harris wrote: Quote: These type of posts is great, not that I have the mech-breaks but I like to see how they look. Really good description an pictures! This is what is great with thesamba and the members!


X2 here. Super post.
X3 ! :idea: 8)
Where's the "like" button? :? :?:
Shouldn't there be a "contributor tips" one too? :idea: :wink: 8)
Happy New Year's and an abundant, and smooth-running 2 0 1 3 to Fellow Sambaistas! :)
Drive intelligently,
GRR

nlorntson Fri Dec 28, 2012 3:49 pm

VWKDF wrote: I was just checking this thread out as I am working on a cable brake chassis at this time and I thought a nice addition to all the information here would be the date of the last cable brake VW, anyone know?

Might be tough to know because they were different for different markets and standard versus deluxe. I bet a trip through Progressive Refinements might clear it up.

volksfahrer Sat Dec 29, 2012 5:22 am

VWKDF wrote: I was just checking this thread out as I am working on a cable brake chassis at this time and I thought a nice addition to all the information here would be the date of the last cable brake VW, anyone know?
once I saw a jan.67 standard bug with cable brakes, looked very original...

8287111 Sat Dec 29, 2012 7:57 am

Last cable brake Standard is 4 630 937 manufactured 5.4-62.

nautica4u Tue Jun 18, 2013 8:21 pm

I have a 1954 standard with cable brakes. would the later years have bigger brakes. If so what would I have to do.

Brezelfahrer Wed Jun 19, 2013 6:03 am

hello nautica

I am restoring a 1952 standard, and had the chance last month to buy a driving 1959 ragtop euro standard. The brakes have not changed in that period, that's for sure.

From your question, I assume you want better brakeperformance. But good adjusted cablebrakes have the same performance as good hydraulic ones. So you'd better give them a good treat!
Most of the time it is just the lack of adjustment of the brakes, because they require more maintenance than hydraulics.

But I can name you one solution to "upgrade" your system: work with later hydraulic VW model brakeshoes that are wider. But these will only fit by carfully cutting out your drums.
I saw a German standard last year september, with a small caravan on a meeting. The owner explained me this type of upgrade, to be able to drive safely with his 400kg caravan and loaded oval for the holidays.

One thing will not change, the calf fitness you receive when applying your cable brakes. This is the only comfort advantage I see when comparing to hydraulic brakes. You gotta love the system (and the system will love you) :o

Hope these lines are of some use for you,
greetz, Peter

Kapt. Q Wed Jun 19, 2013 3:40 pm

It's not all negative with cable brakes, a broken cable with a a schwimmwagen or kubelwagen in WW2 still left the operator with three good brakes, unlike a jeep where one broken hydraulic line meant the loss of all brakes in its single circuit system! A distinct advantage in a military vehicle.

Cheers!



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