Hello!

I just noticed that the parking brake in our trailer grabs only right side wheel. Failure analysis was pretty quick, the cable connecting the two sides is broken.


Rear axle assembly

That black plastic cover I am trying to remove


After having a look on the structure, it was clear that without any tips disassembling the brake cover most likely leads to cracked plastic parts and a handful of misery.

I contacted Thule, and their only advice was to purchase the entire rear axle assembly, which costs a ridiculous amount of money.

Has anyone been able to replace the wire as diy?

I have tried to search for experiences regarding this, but with no luck.

Thanks for any tips!

Br,
Simo

Okey with the help of some German bicycle forum posts I managed to perform the job! I thought to write the steps here in case useful for someone else in the future.

Required spare parts are just a 1,0...1,5 mm cable (length will be about 670 mm) and two screw nipples with diameter 5 mm and length 7 mm. This is a bit oversize but seems to be well available in the market. Original cable nipple is 4 mm in diameter, but I did not find those easily so I chose the closest.

Disclaimer: Not an official repair instruction. Do at your own responsibility, and some steps require mechanical-oriented experience to be performed correctly and safely!

• Remove the wheels
• Remove the brake discs by removing six screws holding the black plastic hub
• Next the wheel bearing with aluminium rotor needs to be pulled out from the shaft
  • Remove the retaining ring preferably with dedicated retaining ring pliers
  • Use either a bearing puller or just grab the aluminium rotor in a vice and tap the shaft gently using suitable arbor, I used a 11 mm socket
  • Note that the tapping might harm the bearing as the force goes through the bearing balls, so it might be wise to replace the bearing during the job
• After removing the bearing you can see two screws holding the plastic brake cover, remove those while holding the cover
• Gently open the cover, there are some springs that might come loose, but it is easy to reassemble
• Remove the broken cable end from the red housing
• Measure the cable length, take care to match original length. It's better to leave it a bit long, because you can move the screw nipple and shorten the cable, making it longer is more difficult…
• Slip the cable into the original cover and install the screw nipples
• Enlarge the D4 mm hole in the red plastic housing with D5 mm drill, there is plenty of material
• Place the new cable ends to the red housings
• Reinstall all parts in reverse order, take care that all parts inside the brake housing are inserted in similar manner as they were
  • I heated the bearings to 100°C before installation, but they still needed some tapping to install on shaft, use some tool to tap from the inner ring of bearing to avoid making (more) damage to it
  • More heat would help, but the seals in bearing don't like more than 100°C, perhaps some freezing spray for the shaft would help a bit.

Unfortunately I did not take any pictures of the steps, or write down the bearing type. I'm sure the bearings are easily available in any bearing retailer. If you want to replace the bearings, just heat the bearing+rotor assembly to 100°C, then the rotor slips easily off from the bearing as aluminium expands more than steel.

Luckily I managed to fix the parking brake with these steps, it took maybe 30 minutes in total and cost me 8€ instead of the 250€ for the whole axle assembly. Happy days!

Nice write up, I don't have this trailer but perhaps it will find use from some other Thule Chariot owner.