Puch VZ50 Fork Rebuild


When purchased, the forks on the Puch wouldn't compress. So they were dismantled to find the problem. Once freed up, they leaked oil badly because the stanchions were corroded, so parts were replaced to make them good again.
New fork parts for rebuild








To start, The fork springs were removed. This meant removing the 4 bolts holeing the handlebars and clocks and undoing the fork top bolt with a 24mm spanner.

Removing a fork Spring.








After the front wheel and front mud guard had been removed one fork leg was removed from the bike by releasing the lower fork clamp bolt (circled) and pulling the fork downwards.

Once removed from the bike the rubber bellows could be slid off the top.









To remove the lower fork leg from the stanchion, the nut on the bottom was removed using a 10mm socket. A slotted screwdriver was used to hold the damper rod from turning which meant some grips were used to turn the socket.

Releasing damper rod nut








A piece of angle iron was drilled with two 8mm holes 44mm apart, to hold the lower fork leg with the existing mud guard studs.
These were threaded for non-standard M7x1mm nuts.

Using this to hold the lower fork leg, a large spanner was used to unscrew the top cap of the fork containing the seals.

Releasing fork top cap








With the top cap removed the fork stanchion can be slid out of the lower fork leg.
The bushes can be checked for wear and the stanchion for corrosion.

Sliding the stanchion from the fork leg








To replace the seals it was necessary to remove the bushes and the top cap.
To remove the bushes the 24mm spanner was used on the damper valve housing.

the stanchion was helpd in the vice with the larger diameter /re-enforced part of the stanchion held in the jaws.












The image below shows the fork parts laid out in order and the image to right the damper valve assembly.

Damper valve parts

Fork parts








The Stanchions on this bike were pitted where the seal fitted and the bushes were worn, so new stanchions, seals, bushes and oil were used to rebuild the forks.









A new seal was fitted into the housing with the orientation shown.










Followed by a new felt wiper seal (note the orientation).

The wiper seal was oiled with fork oil before sliding it on to the Stanchion.









New bushes were fitted and then the damper rod and spring inserted into the stanchion before re-fitting the valve assembly.









A washer and sealing o-ring were fitted to the end of the damper rod with the washer orientated to protect the o-ring from being crushed.









Before refitting the fork leg back on the bike new rubber buffers were inserted into the lower shroud.









Once the forks were fitted back on the bike, each leg was filled with 110cc of 5W fork oil.








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