Cylinders, heads, shafts and axles can be rusted on, or stuck with old gasket cement. Force breaks parts. Oil, small movements and time free them.
Safety
- Support the bike and the part. A freed part can fall.
- Wear eye protection.
You need
- Penetrating oil, a dead-blow hammer (a hammer filled with shot) or a rawhide or plastic mallet, and patience.
Steps
- Spray penetrating oil all round the joint. Let it soak. It gives best results after a few hours, and it may need renewing after a day or two.
- Move the part a little in one direction with a gentle blow or a twist.
- Spray again. Move it back the other way.
- Repeat. Each cycle should gain a little. Go gently, go slowly, but keep going.
- When the part moves freely, lift it off. Keep it square so it does not bind.
- Clean the faces and coat any shaft with oil or anti-seize before refitting. Replace the oil that the penetrating spray washed away: it does not last.
Tips
- Never lever on cylinder cooling fins or thin aluminium edges: see Tap a stuck cylinder loose without breaking the fins.
- Never use a hard steel hammer directly on a part. Use a soft-faced hammer or put a block of wood or brass between.
- Mild household acids such as vinegar or lemon juice can also dissolve rust, but they need time.
Check your work
- The part moved freely and was not damaged.
If it did not fix the problem
- A stuck axle: Drive a stuck axle out with a nut and a brass rod.
- A stuck fastener: Remove a rounded, seized or broken fastener.