Demco Gravity Flow 550 User Manual page 17

Loosen the bleeder valve one turn and pump the
master cylinder until the air bubbles stop coming
out of the hose in the glass container, then close
the bleeder valve and repeat the process on the
other wheels. (Watch the fluid level in the master
cylinder and refill so level does not fall below 1/2
full). Refill master cylinder every 4 or 5 strokes.
Dispose of contaminated brake fluid according to
local regulations.
4. After bleeding is completed, refill the master cylinder
and put the filler cap on securely . Replace the flat
spring behind the emergency lever.
To test the brakes use a wrench or vise grip and clamp
onto the top of the emergency lever to lengthen it.
Pull lever forward until lever locks on the second
click. The lever should be approximately straight up
and down. Now try to rotate each of the four wheels
in a forward rotation. You should not be able to rotate
the wheels forward. If you can, then release the
emergency lever by wedging a screwdriver under
the flat spring behind the lever and set each wheel
brake adjustment up 2 or 3 notches. Then repeat
the test procedure.
Step one: Remove the lever guide and flat spring. Take the S-hook off the lever, take the lever out from
the inside.
Step two: Install the new lever from the inside and up through the slot. Replace the new flat spring and the
lever guide. Replace the push rod and master cylinder and new gasket.
Step three: Take the new chain and fasten the S-hook to the lever by squeezing the hook shut with a pliers.
Check the master cylinder and fill with DOT 3 or 4 brake fluid.
Step four: Re-bleed brake system.
1. Before towing check to be sure master cylinder is full of brake fluid and check lines for leaks. Inspect the
actuator for bent or worn parts. Replace parts if necessary. Make sure the actuator mounting bolts are tight.
2. Periodically check braking quality, as described above. Failure to do so can result in loss of braking.
3. If units are used in corrosive conditions the actuator and wheels should be washed out with high pressure
water. When actuator parts are dry, oil all moving parts.
5. Be sure Pin and hitch rating is equal to or greater than
6. Connect the emergency chain hook to towing
7. If the emergency brake lever is accidentally applied
Replacing The emergency lever
MAINTeNANce
Page 17
hitching The Wagon
the wagon GvWR.
vehicle.
while unhitching, release the lever by pulling it forward
and with a screwdriver lift up the front of the flat spring
until it releases the lever. Many times these parts are
damaged when this happens. An inspection of the
lever, flat spring, and chain with S-hooks is required
and any damaged parts must be replaced.