521 Technical data
Fuels, coolants, lubricants, etc.
Fuels, coolants, lubricants, etc.
Capacities
Vehicle components and their respective
lubricants must match.Therefore only use products tested and
approved by Mercedes-Benz.Please refer to the Factory Approved
Service Products pamphlet, or inquire at
your Mercedes-Benz Light Truck Center.
Model
Capacity
Fuels, coolants, lubricants, etc.
Engine with oil filter
R 350
R 500
8.5 US qt (8.0 l)
9.0 US qt (8.5 l)
Approved engine oils
Automatic transmis-
sion
9.5 US qt (9.0 l)
MB Automatic Transmission Fluid
Transfer case
0.53 US qt (0.5 l)
MB Automatic Transmission Fluid
Rear axle
1.2 US qt (1.1 l)
Hypoid gear oil
Front axle
1.2 US qt (1.1 l)
Hypoid gear oil
Power steering
approx. 1.3 US qt (1.2 l)
MB Power Steering Fluid
Front wheel hubs
approx. 1.5 oz (43 g) each
High temperature roller bearing grease
Brake system
-
MB Brake Fluid (DOT 4+)
523 Technical data
Fuels, coolants, lubricants, etc.
Engine oils
Engine oils are specifically tested for their
suitability in our engines and durability for
our service intervals. Therefore, only use
approved engine oils and oil filters re-
quired for vehicles with Maintenance Sys-
tem (U.S. vehicles) or FSS (Canada
vehicles). For a listing of approved engine
oils and oil filters, refer to the Factory Ap-
proved Service Products pamphlet, or con-
tact an authorized Mercedes-Benz Light
Truck Center.
Engine oil additives
Do not blend oil additives with engine oil.
They may damage the engine.
Damage or malfunctions resulting from
blending oil additives are not covered by
the Mercedes-Benz Limited Warranty.Air conditioning refrigerant
R-134a (HFC) refrigerant and special PAG
lubricating oil are used in the air condition-
ing system.
Never use R-12 (CFC) or mineral-based lu-
bricating oil. Otherwise damage to the
system will occur.
Brake fluid
During vehicle operation, the boiling point
of the brake fluid is continuously reduced
through the absorption of moisture from
the atmosphere.
Only brake fluid approved by
Mercedes-Benz is recommended. Your
authorized Mercedes-Benz Light Truck
Center will provide you with additional in-
formation.
!Using engine oils and oil filters of
specification other than those express-
ly required for the Maintenance System
(U.S. vehicles) or FSS PLUS (Canada
vehicles), or changing of oil and oil filter
at change intervals longer than those
called for by the Maintenance System
(U.S. vehicles) or FSS PLUS (Canada
vehicles) will result in engine damage
not covered by the Mercedes-Benz
Limited Warranty.
Please follow Maintenance System
(U.S. vehicles) or FSS PLUS (Canada
vehicles) recommendations for sched-
uled oil changes. Failure to do so could
result in engine damage not covered by
the Mercedes-Benz Limited Warranty.
Warning!
G
Under extremely strenuous operating condi-
tions, this moisture content can lead to the
formation of bubbles in the system, thus re-
ducing the system’s efficiency.
Therefore, the brake fluid must be replaced
regularly. Refer to your vehicle’s
Maintenance Booklet for replacement inter-
val.
