Stryker 721, Maintenance Manual

Page: 16 / 196

Service Information
12
CHECKING HYDRAULIC FLUID LEVEL
Required Tools:
3/8 Open End Wrench
3/4 Open End Wrench
Procedure:
WARNING
To avoid personal injury or damage to the stretcher, remove the litter and the base hood before beginning
service on the jacks.
1. Using a 3/8 open end wrench, remove square head set screws from both head and foot end jack support
tubes. Remove litter top and set aside.
2. Lift base hood off base frame and set aside.
3. Be sure there are no hydraulic leaks. If there are, jack replacement will be necessary.
4. Lower the jack to the full down position.
5. Using a 3/4 open end wrench, slowly turn the fill plug located on the side of the reservoir counterclockwise
to allow excess system pressure to vent. Remove the fill plug.
6. The hydraulic fluid should be visible at the bottom of the fill hole. If it is not, add Mobil Aero HFA hydraulic
fluid (Stryker part number 2020–70–475) until the fluid is visible at the bottom of the fill hole. Replace the
fill plug.
CAUTION
Use of other types of oil may damage hydraulic units.
7. Replace the hood and the litter.
REMOVAL OF EXCESS AIR (VACUUM) FROM THE HYDRAULIC SYSTEM
Procedure:
1. Verify all hydraulic linkages are secure and operating properly (see pedal linkage adjustment procedure
page 8 or 9).
2. Using pump pedal, actuate system several times. This will force the air through the system and the jack
should now pump up.