Technical Hand brake cable replacement (no braking on the left side)

[Zardo]

Hi folks,

My handbrake isn't tightening progressively when I pull the lever. When I changed the wheels and put my set of winter tyres on, I also found out that, using the hand brake, there is no braking action on the rear left disk, only on the right side.

I removed the cover and found this (the left side cable is the upper one in the image, the one closer to the lever):

Here in this view, the left side cable is the lower one in the image:

I tried pulling manually on both wires but a difference in tension between left and right wasn't evident to me. I didn't disconnect the cables, maybe it would have been more evident then.

What could be the cause, can the cable slip where it is connected with the rear brake hydraulics (or is its action purely mechanical?) Maybe the cable has ruptured, but if so, why is there tension present?

Any ideas? Several years ago, a set of brake disks were replaced by an official Fiat garage, but I don't remember if it was front or rear. To my knowledge, there has never been any work on the handbrake or its cables (I bought the car new in 2011).

I have already ordered a left-side cable, but I still need to get an appointment to rent a hydraulic platform in a DIY-garage.

Thanks

 

[There all puntos]

When you operate the rear discs by cable (the handbrake) does the cable (at the lever on the disc caliper) move any? Maybe the holder has fallen off/ failed or failed on the beam axle arm the cable is on?

Had a similar thing happen on my Fiat Stilo, but the worm driving the piston had failed, so had to buy reconditioned calipers (no sense in replacing one side) as it would have made the rear brake bias out of balance. And easier to replace both calipers, than try to rebuild them (did try, failed, still have one replacement kit, complete with seal and worm/ piston/circlip). And the one I did manage to do, failed on me (it jammed on) during its MOT

All adjustments are done inside, and both side of the inside compensator should be level.

Or it might have failed as it goes through the floor? It takes two people to check a brake system. The cable can be quite easily replaced from the ground, using a hydraulic jack, with decent lift and normal chassis stands.

Can't do anything now as it's brass monkeys out.

 

[Zardo]

I made a video.

The left-hand cable is still attached but it makes sudden cracking noises, and when it does that, the tension gives. There is some residual manual braking power on the right side, but basically nothing on the left side.

Also, it‘s almost as if the left-hand cable has become longer since the balancer plate is no longer perpendicular to both cables.



Any ideas?

Thanks

EDIT: I asked ChatGPT.

The most likely fault is a failure in the self-adjusting mechanism inside the left rear caliper. This could cause the lever to lose its ability to apply sufficient force to the piston, leading to slack in the cable and an uneven balancer plate. Disassembling and inspecting the caliper will provide a definitive answer.

Maybe it‘s better to simply replace both calipers and brake pads and both cables with new parts, and replace the brake fluid, too, while at it? Basically, just throw a huge pile of cash at it?

I found these links:

Rear left calipera: https://www.bremboparts.com/europe/en/catalogue/caliper/F_23_156/pdf
Rear right caliper: https://www.bremboparts.com/europe/en/catalogue/caliper/F_23_157/pdf

 

[Zardo]

Hi,
so I finally replaced the left brake caliper with a remanufactured caliper from Brembo as the original new one cannot be ordered anymore.

There is now at least some braking action by pulling the hand brake on the left rear disk brake. But it's clearly weaker than it was when the car was new.

However the balancer is still tilted with the left cable having less tension.

I wonder whether:

- the spring of the remanefactured caliper is weaker than the original one

- upon remanefacturing, the lever which is gripped by the handbrake cable was fitted with a wrong angle (which decreases the distance to the cable)

Can the lever of the caliper be adjusted at another angle?

 

[Zardo]

To wrap this up:

This shows the lever of the remanufactured left rear disc brake caliper after bleeding and tightening of the central balancer adjustment screw:



The problem was, the balancer plate was tilted and the left handbrake cable was kind of slack with the right rear brake already gripping.

After help from the forum and complying with the correct procedure for adjustment:

Mark the position of the nut, then loosen the handbrake cable adjustment nut by at least two or three turns to ensure the cable is completely slack.

- Start up the engine and operate the brake pedal at least ten times energetically.

- Place the handbrake lever in the fifth notch on the toothed sector.

- Tighten the adjustment nut on the handbrake lever until the rear wheels are not braked.

- Check that the wheels are free to turn with the lever in the rest position.

- Switch off the engine.

The only difference is, I marked the adjuster screw, slackend it by 15 revolutions (until I could remove both cables), did the above procedure (braking hard with the foot brake ten times with the engine running and driving at a slow pace with the handbrake cables totally slackened), then I tightened the adjuster screw progressively by 5 revolutions at a time and yanking the hand brake all the way up several times until I reached 15 revolutions again.

With the handbrake not pulled, I was able to move the car whilst sitting in the driver seat and pushing against the ground with one foot. I drove up a small hill with basically no braking. But the left rear piston now clearly touches the disc permantently as the rear left disc showed an increased temperature of 55°C while all the other three were ambient temperature. The rear brakes would already engage after pulling the handbrake to the first ratched. So I slackened the adjuster screw of the balancer plate by one revolution.

I drove down the hill using only the hand brake intermittently several times. The braking action on the rear brakes increased a lot after all this, but this also increased both rear disc temperatures to around 210 - 244 °C (the temperature fluctuates a lot depending where on the disc I point the IR thermometer). There was a bit of smoke. I slackened the adjuster screw by another revolution and drove around in the flat for 2 km without applying the brake. It was probably too short a drive to allow for the rear discs to cool down, since after that both rear disc still had 100°C.

I'll test temperatures again tomorrow but the feel of the handbrake is basically like new. I heard at least one tyre screech after pulling the hand brake hard.

The tilting of the balancer plate actually diminished after doing all this, but it did not entirely level out:



The rear right brake caliper is still original and except for bleeding it, I didn't do anything with it.

Let's see what the MOT tomorrow will show, if the hand brake action brakes the rear wheels symmetrically or not.

Thanks.

 

[rmjbn1]

Mine was at an angle for a few years (rear drums)
Until one of the cables snapped.
With a new cable the balance bar at the lever is now level.
The outer casing had split at one of the bends, inner cable rusted, frayed and stretched.
Have you replaced the cable yet?

 

[Zardo]

Mine was at an angle for a few years (rear drums)
Until one of the cables snapped.
With a new cable the balance bar at the lever is now level.
The outer casing had split at one of the bends, inner cable rusted, frayed and stretched.
Have you replaced the cable yet?

I bought the left cable, but I haven't replaced it yet. A lot of the cable is actually hidden under some bottom plastic protections.
I might do this the next time I rent a lift (or if the car doesn't pass the Swiss MOT).

I also bought a remanufactured caliper for the right side, but since it was my first time doing this, took me 6 hours to just change the left one, clean the bracket, the brake pads, apply copper paste to every nut and bolt, change the guiding pins and bleed. I actually had to bleed it twice since only bleeding the replaced caliper isn't sufficient as a lot of air was sucked into the hydraulics when the hose was disconnected, so I had to go back to the lift the very next day and fully bleed it again on all 4 wheels using 2 liters of brake fluid and a pressure tool.

 

[bugsymike]

I bought the left cable, but I haven't replaced it yet. A lot of the cable is actually hidden under some bottom plastic protections.
I might do this the next time I rent a lift (or if the car doesn't pass the Swiss MOT).

I also bought a remanufactured caliper for the right side, but since it was my first time doing this, took me 6 hours to just change the left one, clean the bracket, the brake pads, apply copper paste to every nut and bolt, change the guiding pins and bleed. I actually had to bleed it twice since only bleeding the replaced caliper isn't sufficient as a lot of air was sucked into the hydraulics when the hose was disconnected, so I had to go back to the lift the very next day and fully bleed it again on all 4 wheels using 2 liters of brake fluid and a pressure tool.

I would probably fit the one or ideally both new handbrakes cables, looking at one of your videos you certainly get a lot of road muck around it.

 

[Zardo]

I passed the MOT, rear braking values were 1.74 left and something around 1.55 right (the left brake pads were thouroughly cleaned with brake cleaner when I changed the left caliper, the right ones were not) - don't know what units they use. By memory, front braking values (brake pedal) were around 4.4 and 4.3 if I remember correctly.

 

[jackwhoo]

Hi,

Slacken the cable adjuster right off , make sure both levers on the calipers are released back to their rest points, gently tighten adjuster nut until there is a very slight slack in the cable.

The levers on the calipers should not be pulled at all when handbrake released.

It appears someone has previously adjusted the cables too tight which is infuriating and common .

Best wishes
Jack