Fault.

Cause.

Remedy.

Fork is stiff in action.

Lack of lubricant on bearings.

Apply grease gun (six shots).

Ditto

Wheel spindle incorrectly adjusted.

Slacken clamp on axle fitting. Bounce fork a few times, and re-tighten.

Ditto

Fork crown clamp bolts so tight that outer tube becomes distorted, and presses on piston.

Slacken bolts until fork moves freely.

Ditto

Split      bearings       PD 1677   have       been assembled with foreign matter be­neath them, causing tightness in bore.

Dismantle split bearings, and    remove high spots.

Malalignment.

See instructions on Removing Front Wheel (Re aligning outer tubes). Pages 15

Fork is stiff in action.

Outer or inner tubes damaged accidentally.

Replace.

Insufficient damping

Lack of oil.

Top up.

Ditto

Viscosity of oil too low in tropical climates.

Replace     oil       with Mobiloil BB or Castrol XL.

Damping too fierce.

Oil too viscous.

Replace oil with re­commended grade. If this is already in use, excessively low temperatures will have the same effect, but this is not usually serious, as the additional damping improves the steering characteristics under icy road conditions.

Fork "bottoms" readily.

Lack of air.         

Inflate to correct position.

Ditto (fork correctly inflated with air)

Lack of oil.

Top up.

Fork hammers on full extension.

Over inflation.

Deflate to correct position.

Fork loses air pressure (oil traces on lower sliding tubes)

Leaking gland ring.

Replace. Examine bores  for scores. If these are too deep to be polished out, replace outer tubes.

Ditto

Leaking static seal on piston PP 17-1.

Replace faulty seal.

Ditto (oil traces around top of outer tube)

Leaking static seal PD 17-22 on top internal fitting.

Replace faulty seal.

Ditto

(no oil leakage).

Leaking inflation valve core;

or

Leaking inflation valve washer PD 1561-43,

or

Leaking   static  seal PP 17-22;

or

Leaking static seal PP 17-17;

or

Leaking balance pipe

Replace faulty part.