Freightliner XC Chassis Radiator Surge Tank Replacement
Tools Required
Ratchet with
14mm socket and short extension
14mm open/closed end wrench
12mm socket
Long flat blade screwdriver
Crescent wrench
Standard pliers
Small phillips screwdriver
One Quarter
Two one-gallon water jugs

Paper towels
Distilled water

Time Required
About one hour.


Procedure
Gain access to the top of the tank from inside the motorhome. For a 2004 Discovery: use a quarter to remove
the four large screws of the access panel located inside the rear
wardrobe closet. Pull up the carpet along the
passenger side edge and dispose of carpet staples
left in the floor. Lift the passenger's side of the access
panel and support open to 45 degrees or better.

Slide the two small hose clamps away from the vents on top of the tank with pliers. Grasp the hoses and apply a
gentle twisting force on the hose itself with the pliers to break the grip. Slide the hoses off, noting which hose
goes where.

Remove the two driver's side 14mm bolts
and nuts. The rear bolt should remain captive by the structure below,
and can be reached from the side with the 14mm wrench.
Remove the forward passenger's side bolt and nut.

From the outside, remove the phillips screws holding the passenger side edge of the
vertical black rubber
shield. P
ull the shield over the transmission filler cap and fold away as much as possible. Remove the clamp
holding the transmission filler tube in place. Push the tube down so the 14mm wrench can get a grip on the
inside nut and remove the bolt
and nut.

From the inside
again, remove the small overflow hose on top. Disconnect the sensor connector by lifting up
gently on the retaining clip first and then pulling the connector straight back
. Slip the clamp off the large lower
hose and wriggle almost free. Place towels under the hose and disconnect the hose. As soon as the hose
comes free, place your thumb over the surge tank opening
to minimize fluid loss. Lift the tank out and drain
contents into the two one-gallon jugs. You should only have lost about a cup of fluid.

Remove the
old tank sensor with a crescent wrench, noting that the black switch housing is off-center, closer to
the top. I
nsert the sensor into the new tank and tighten until the sensor is snug and the housing is in the same
position as with the old tank
to duplicate the previous tightening torque. No tape or dope should be required
because of the existing
small nylon washer.

P
ut the new tank into position and replace the four retaining bolts, four hoses, and switch connector. Note: the
flat screwdriver can help in lifting the rear driver's side bolt up until the nut and washer are connected.
Refill the
tank with the collected fluid, and replace the spilled fluid with
an equivalent amount of distilled water. Swap the
radiator cap from the old tank. Reposition the access cover.
Go back outside and reposition the transmission
filler tube and rubber shield.