Rough Z-Axis Adjustment

Over time a tiny amount of abrasive can make its way into the z-axis adjustment block and make it difficult and rough to set the z height of the Nozzle.  The following guide will walk you through dissembling and cleaning the assembly.

Tools Needed

  • 4 mm Allen Key
  • 17 Wrench or socket 
  • Torque Wrench with 17 mm Socket
  • Clean Rags 
  • Compressed air if available.


1.    Remove the Abrasive hose, Touch off tool, and Z Adjustment knob.
2.    Use the 4 mm Allen key to remove the Nozzle assembly from the Z-block.  
3.    Use a set of pliers to hold the mixing chamber while losseing the banjo bolt with a 17 mm wrench or socket.
4.  Tape up the washers and the end of the banjo bolt to keep debris from getting into the hp system
5.    Pull the bellow off the top of the Nozzle assembly to expose the snap ring.
6.  Using  the pliers to remove the snap ring.  Safety glasses are recommended as the ring and come flying off if you aren't careful.  If you are having trouble try getting setup exactly as in the picture. The ring should pop off with only minimal force
7.  Remove the adjusting block and bellows from the guide rod.
8.  Wipe down the guide rod using the clean rag.
9.  Pull the Z Bellows off of the adjusting block
10.   Using compressed air, blast out any any abrasive clinging to to the inside of the block.  Always wear safety glasses when using compressed air.  Alternatively you can use a clean rag to remove abrasive from all surfaces.

11.  Using compressed air, blast out any any abrasive clinging to to the inside of the bellows.  Alternatively you can try to wipe out any abrasive.

12.  Re-install the lower bellow.  Pull the bottom lip over the retaining ring groove
13.  Install the adjustment block take note to match the orientation of the bellow ( round to round and flat to flat)
14 Install the top bellow the same way and push everything down
15.   Install the snap ring using pliers. It should go on easily.
16.   Lift the top part of the bellow over the snap ring.  Once secured pull down the bellow to make sure it is correctly seated.
17 Re-install the banjo bolt using the torque wrench and pliers. The Torque should be 17 Nm.  Also take care that the hose exist relative to the abrasive inlet of the head is correct.
18.  Install the nozzle back onto the Z-block using the 4 mm Allen key
19. Re install the abrasive hose and touch off tool

Next Time

Try to wash down the Z knob before using and also pay attention if you see the z- bellows pulling up push them back down before abrasive can enter the system