Husqvarna 555 Workshop Manual page 44

6. Attach the new fuel hose to the fuel tank as the
illustration shows.
7. Attach the fuel filter to the new fuel hose.
8. Install the fuel tank cap.
9. Install the fuel tank in the opposite sequence. Refer
To remove and install the fuel tank on page 41 .
to
7.15.4 To replace the air purge bulb
1. Remove the cylinder cover and the air filter.
2. Remove the suction hose (A) and the return hose
(B) from the air purge bulb.
3. Push the snap locks to remove the air purge bulb
from the air filter holder.
A
B
4. Replace the air purge bulb.
5. Install in the opposite sequence.
7.15.5 Air pressure in the fuel tank
The two-way tank valve has a controlled opening
pressure in the two directions. The controlled opening
prevents positive pressure or vacuum in the fuel tank,
and fuel leakage. Positive pressure, vacuum and fuel
leakage decreases engine performance.
7.15.5.1 To do a pressure test of the fuel tank
1. Remove the fuel tank cap and drain the fuel tank.
2. Pull out and remove the fuel hose.
44 - Repair instructions
3. Connect the pressure tester to the tank valve (A).
4. Do a test of the negative pressure in the fuel tank.
a) Use the pressure tester in vacuum mode to
decrease the pressure in the fuel tank.
b) The pressure must be between 0.10–0.45 bar.
5. Do a test of the positive pressure in the fuel tank.
a) Use the pressure tester in pressure mode
increase the pressure in the fuel tank.
b) The pressure must stop at max. 0.07 bar.
6. Install the fuel tank cap.
A
1540 - 001 -