Question 1

Which engine oil does the Smart Fortwo 451 need?

Accepted Answer

Owners agree on fully synthetic oil approved to Mercedes-Benz sheet 229.5, in the correct viscosity. The petrol 451 takes about 3.5 litres (3.7 US quarts) with a filter change.

Question 2

Which gearbox oil does the Smart 451 use, and how much?

Accepted Answer

75W-90 gear oil to API GL-4, about 2.3-2.5 litres.

Question 3

How do I reset the Smart Fortwo 451 service indicator?

Accepted Answer

When the cluster shows "smart", double-press the left cluster button and switch the ignition off. Then hold the button while you turn the key to position 1 until the service reminder resets.

Question 4

How do I bleed the cooling system after changing coolant?

Accepted Answer

Bleed it from the top. Raise the front of the car, loosen the upper hose at the cylinder head, fill through the expansion tank and refit the hose when coolant flows out without bubbles. Filling from the bottom often traps air and can cause overheating. Never open a hot cooling system.

Question 5

Do I need a special tool to fit a new clutch actuator?

Accepted Answer

Not to fit it. The 451 actuator has a built-in self-adjuster, and owners fit the new one at the same marks as the old one. If a clutch teach-in is still needed, it is done with a diagnostic tool (Mercedes-Benz STAR or a compatible scanner).

Question 6

How do I get the manual after payment?

Accepted Answer

You receive a download link by email after payment. You can save the PDF and print the pages you need.

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