Step 6 of 8 · Clean

How to clean a hydraulic hose assembly

Remove cutting dust and metal particles from the bore, then cap both ends at once so the assembly stays clean.

  1. 1 Select
  2. 2 Cut
  3. 3 Skive
  4. 4 Insert
  5. 5 Crimp
  6. 6 Clean
  7. 7 Test
  8. 8 Inspect

What this step does

Cutting a hose leaves rubber dust and metal particles inside it. If they are not removed, the first time the machine runs they are carried into valves, pumps and cylinders. Contamination is widely regarded as the leading cause of hydraulic component failure, and a new hose is a common way it gets in.

Cleaning happens after crimping, because cutting, skiving and inserting all create debris. It is followed immediately by capping.

How to do it

  1. Choose the method. Projectile cleaning fires a foam pellet slightly larger than the bore through the hose with compressed air, wiping the wall. Fluid flushing pumps clean, filtered fluid through at high velocity.
  2. For projectile cleaning, select the pellet and nozzle size for the hose bore.
  3. Fire the projectile through the hose into a catcher. Inspect it: a dirty pellet means the hose needs another pass.
  4. Repeat from the other end until the projectile comes out clean.
  5. Cap or plug both ends straight away with clean caps.
  6. Store the assembly off the floor, away from dust, until installation.

Checks before moving on

  • The last projectile fired came out visibly clean.
  • No projectile is left inside the hose — count them in and out.
  • Both ends are capped with clean caps of the correct size.
  • If the customer specifies a cleanliness level, the method used can meet it.

Common mistakes

  • Blowing the hose out with shop air only. Air alone does not wipe the wall and often carries water and oil.
  • Cleaning before crimping and not after.
  • Leaving a cleaned hose uncapped on the bench.
  • Using a projectile too small for the bore, so it passes without contact.

Equipment and consumables

  • Projectile launcher with nozzles for each bore size
  • Foam projectiles sized to the hose bores you make
  • Projectile catcher
  • Clean, dry compressed air
  • Caps and plugs for every thread size

Settings such as crimp diameter, skive length, insertion depth and test pressure are specific to the hose and fitting manufacturer. Use their current specification.

Frequently asked questions

Why does a new hydraulic hose need cleaning?

Cutting and assembly leave rubber dust and metal particles in the bore. On start-up they are flushed into the system and damage pumps, valves and seals.

What is projectile cleaning?

A foam pellet slightly larger than the hose bore is fired through the hose with compressed air. It scrubs the inner wall and pushes debris out ahead of it. It is fast and suits most workshop hose assembly.

Is blowing compressed air through the hose enough?

No. Air does not remove particles stuck to the tube wall, and unfiltered shop air can add moisture and oil. Use a projectile or a fluid flush.

Useful at this step

Scroll to Top