After the aircraft took off from London-Gatwick Airport, the landing gear was selected up but the gear position indicators remained red, indicating that the landing gear was not in the position selected. The crew followed the emergency checklist and selected gear down and the indications changed to green, indicating that the landing gear was now down-and-locked. The crew elected to continue to Guernsey, Channel Islands with the undercarriage down. The aircraft performed an ILS approach and landed on runway 27. On touchdown, the aircraft pulled to the left and the co-pilot reported that there was no brake pressure. The commander suspected a tyre had burst and that hydraulic pressure had been lost. He therefore changed to the alternative braking system, slowed the aircraft and vacated the runway. The flight crew continued to taxi the aircraft and eight minutes passed before Guernsey ATC were informed that a tyre may have burst. Another aircraft landed on the runway during this period and before a runway inspection was initiated. Once G-RAJJ was parked, the crew discovered that the shock absorber on the left landing gear had separated and the tyre on the No 1 mainwheel had burst. Debris from the tyre and shock absorber was subsequently found on runway 27. The shock absorber separated either as a result of a hard landing, or incorrect gas pressures and oil level in the shock absorber. The physical damage to the shock absorber diaphragm threads and locking bolts started at least two flight cycles prior to the accident flight and may have occurred whilst it was fitted to another aircraft. PROBABLE CAUSE: The investigation report did not contain a probable cause paragraph as recommended in ICAO Annex 13.