Bobcat S150. Manual - part 21

S150 Bobcat Loader

69

Operation & Maintenance Manual

ENGINE COOLING SYSTEM (CONT’D)

Replacing The Coolant

Open the rear door and remove the rear grill.

Remove the cover (2) [Figure 136] from the coolant
recovery tank.

Figure 137

Connect a hose to the engine block drain (1)
[Figure 137]. Open the drain valve and drain the coolant
into a container.

Recycle or dispose of used coolant in an environmentally
safe manner.

NOTE: The loader is factory filled with propylene

glycol coolant (purple color). DO NOT mix
propylene glycol with ethylene glycol.

Premix coolant (53% propylene glycol and 47% water) in
a separate container. For correct capacity, (See Fluid
Capacities on Page 103).

4,3 L of propylene glycol mixed with 3,8 L of water is
the correct ratio (53%/47%) to provide -37°C (-34°F)
freeze protection. (See IMPORTANT, Page 20.)

Use a refractometer to check the condition of propylene
glycol in the cooling system.

Run the engine until it is at operating temperature. Stop
the engine. Check the coolant level in the recovery tank
when cool. Add coolant as needed.

Install the rear grill and close the rear door.

ALTERNATOR BELT

Adjusting The Alternator Belt

Stop the engine.

Raise the operator cab (See Raising The Operator Cab
on Page 56).

Figure 138

Loosen the alternator mounting bolt (1) and adjustment
bolt (2) [Figure 138].

Move the alternator until the belt has 8,0 mm movement
at the middle of the belt span with 66 N of force.

Tighten the adjustment and mounting bolts.

Lower the operator cab (See Lowering The Operator Cab
on Page 57).

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S150 Bobcat Loader
Operation & Maintenance Manual

70

ELECTRICAL SYSTEM

Description

Figure 139

The loader has a 12 volt, negative ground alternator
charging system. The electrical system is protected by
fuses located in the cab on the steering control panel,
and a 100 amp master fuse [Figure 139] in the engine
compartment on the left side of the engine, under the air
cleaner. The fuses will protect the electrical system when
there is an electrical overload. The reason for the
overload must be found before staring the engine again.

Cleaning Battery and Terminals

Figure 140

The battery cables must be clean and tight [Figure 140].
Check electrolyte level in the battery. Add distilled water
as needed. Remove acid or corrosion from battery and
cables with sodium bicarbonate (baking soda) and water
solution.

Put Battery Saver (6664458) or grease on the battery
terminals and cable ends to prevent corrosion.

Fuse Location

WARNING

Batteries contain acid which burns eyes and skin on
contact. Wear goggles, protective clothing and
rubber gloves to keep acid off body.

In case of acid contact, wash immediately with water.
In case of eye contact get prompt medical attention
and wash eye with clean, cool water for at least
15 minutes.

If electrolyte is taken internally drink large quantities
of water or milk! DO NOT induce vomiting. Get
prompt medical attention.

W-2065-1296

Figure 141

The electrical system is protected from overload by fuses
and relays under the fuse panel cover (1) [Figure 141]. A
decal is inside the cover to show location and amp
ratings.

Remove the cover to check or replace the fuses.

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S150 Bobcat Loader

71

Operation & Maintenance Manual

ELECTRICAL SYSTEM (CONT’D)

Fuse Location (Cont’d) 

Figure 142

The location and sizes are shown below and in
[Figure 142]. 

R = Relay

Using A Booster Battery (Jump Starting)

If it is necessary to use a booster battery to start the
engine, BE CAREFUL! There must be one person in the
operator’s seat and one person to connect and
disconnect the battery cables.

The key switch must be OFF (Standard Panel) OR the
STOP Button must be pressed (Deluxe Panel). The
booster battery must be 12 volt.

WARNING

Batteries contain acid which burns eyes and skin on
contact. Wear goggles, protective clothing and
rubber gloves to keep acid off body.

In case of acid contact, wash immediately with water.
In case of eye contact get prompt medical attention
and wash eye with clean, cool water for at least
15 minutes.

If electrolyte is taken internally drink large quantities
of water or milk! DO NOT induce vomiting. Get
prompt medical attention.

W-2065-1296

WARNING

Keep arcs, sparks flames and lighted tobacco away
from batteries. When jumping from booster battery
make final connection (negative) at engine frame.

Do not jump start or charge a frozen or damaged
battery. Warm battery to 16°C (60°F) before
connecting to a charger. Unplug charger before
connecting or disconnecting cables to battery. Never
lean over battery while boosting, testing or charging.

Battery gas can explode and cause serious injury.

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6718774

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5

6

9

17

11

13

15

4

3

8

7

10

20

19

12

14

16

18

N-19660

REF

DESCRIPTION

AMP

REF

DESCRIPTION AMP

1

Traction

30

11

Front & Marker 
Lights

R

2

Fuel Shutoff

30

12

Fuel Shutoff

R

3

Not Used

- -

13

Rear Lights

R

4

Not Used

- -

14

Traction

R

5

Heater 25

15

Switch 

Power

R

6

Front & Marker 
Lights

15

16

Starter

R

7

Rear Lights

15

17

Unswitched 
Attachments

25

8

Bobcat Controller

25

18

Switched 
Attachments

25

9

Not Used

- -

19

Alternator & 
Accessories

25

10

Glow Plugs

R

20

Accessory Plug

25

S150 Bobcat Loader
Operation & Maintenance Manual

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ELECTRICAL SYSTEM (CONT’D)

Using A Booster Battery (Jump Starting) (Cont’d)

Figure 143

Connect the end of the first cable (1) [Figure 143] to the
positive (+) terminal of the booster battery. Connect the
other end of the same cable (2) [Figure 143] to the
positive terminal on the loader starter.

Connect the end of the second cable (3) [Figure 143] to
the negative terminal of the booster battery. Connect the
other end of the same cable (4) [Figure 143] to the
engine.

Keep cables away from moving parts. Start the engine.
(See STARTING THE ENGINE (DELUXE PANEL,
KEYLESS START) on Page 26) and (See STARTING
THE ENGINE (STANDARD PANEL, KEY SWITCH) on
Page 24.)

After the engine has started, remove the ground (-)
cable (4)  [Figure 143] first. Remove the cable from the
positive terminal (2) [Figure 143].

IMPORTANT

Damage to the alternator can occur if:
•

Engine is operated with battery cables
disconnected.

•

Battery cables are connected when using a fast
charger or when welding on the loader. (Remove
both cables from the battery.)

•

Extra battery cables (booster cables) are
connected wrong.

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