Background
The door lock on one of the entry/exit doors of my Mother's caravan had developed a fault. When the handle was turned the door could not be opened. Further examination revealed that the door bolt was not being pulled back sufficiently to clear the lock casing. From the inside the only way to open the door was to use the locking handle to retract the lock bolt a little further. From the outside the only way to open the door was to use the key to retract the bolt fully.
Before buying a replacement unit i thought it was worthwhile looking inside to see if it could be repaired.
Before the lock unit could be removed from the door frame both internal and external handles had to be removed, the Euro Cylinder with thumb turn lock had to be removed and the screws securing the lock to the door frame had to be removed.
Before buying a replacement unit i thought it was worthwhile looking inside to see if it could be repaired.
Before the lock unit could be removed from the door frame both internal and external handles had to be removed, the Euro Cylinder with thumb turn lock had to be removed and the screws securing the lock to the door frame had to be removed.
When the lock unit had been removed from the door frame the four machine screws securing the case covers were removed followed by the case cover itself to reveal the internal workings.
When installed in the door a square bolt passes through the pawl and the inside of the handle. When the handle is rotated the the pawl pills back the lock bolt allowing the door to be opened.
While testing this using the square bolt and manually operating the lock it was clear that the bolt was not being retracted enough.
The pawl surfaces and the rear spring looked worn so i decided to install a spacer which would allow the pawl to retract the bolt an extra couple of millimeters when rotated.
When installed in the door a square bolt passes through the pawl and the inside of the handle. When the handle is rotated the the pawl pills back the lock bolt allowing the door to be opened.
While testing this using the square bolt and manually operating the lock it was clear that the bolt was not being retracted enough.
The pawl surfaces and the rear spring looked worn so i decided to install a spacer which would allow the pawl to retract the bolt an extra couple of millimeters when rotated.
It was not possible to install a spacer such as a washer without damaging the bolt assembly so i used a hook-eye used on curtain tracks and cut off the excess metal. I opened up the eye using pliers and then rolled it around the lock bolt then used the pliers to close the eye again.
The 'spacer' can be seen installed in this photograph.
The modified mechanism was manually tested again and this time the lock bolt fully retracted.
The lock casing was re-assembled and then re-installed in the door.
It was now possible to open the door without it sticking or having to use the key or thumb turn lock.
The entire job took just under 75 minutes. The lock should now be good for another 15 years of service! It was well worth the effort to repair the lock as only a couple of parts showed any signs of wear and the rest look good for a long time to come. It would have been a shame and a terrible waste of resources to throw away a unit which required such a simple repair and can be used for many years to come.
The 'spacer' can be seen installed in this photograph.
The modified mechanism was manually tested again and this time the lock bolt fully retracted.
The lock casing was re-assembled and then re-installed in the door.
It was now possible to open the door without it sticking or having to use the key or thumb turn lock.
The entire job took just under 75 minutes. The lock should now be good for another 15 years of service! It was well worth the effort to repair the lock as only a couple of parts showed any signs of wear and the rest look good for a long time to come. It would have been a shame and a terrible waste of resources to throw away a unit which required such a simple repair and can be used for many years to come.