MTU — Engine coolant - Filling
Maintenance · HT coolant circuit
From a MTU operator's manual covering: 12 V 4000 G23, 12 V 4000 G43, 12 V 4000 G63, 12 V 4000 G83, 12 V 4000 Gx3, 12/16V 4000 Gx3, 12V 4000 G23, 12V4000 G23, 16 V 4000 G23, 16 V 4000 G43, 16 V 4000 G63, 16 V 4000 G83. Check it applies to your exact model before use.
Applies to: MTU 12 V 4000 G23, MTU 12 V 4000 G43, MTU 12 V 4000 G63, MTU 12 V 4000 G83, MTU 12 V 4000 Gx3, MTU 12V4000 G23, MTU 16 V 4000 G23, MTU 16 V 4000 G43, MTU 16 V 4000 G63, MTU 16 V 4000 G83, MTU 12V/16V 4000 Gx3 engine
Before you start
- Coolant is hot and under pressure - risk of injury and scalding; let engine cool down; wear protective clothing, gloves and goggles.
- Cold coolant in hot engine can cause thermal stress - fill only into cold engine.
Procedure
- Turn breather valve of coolant expansion tank counterclockwise to first stop and allow pressure to escape.
- Continue to turn counterclockwise and remove.
- Connect suitable pump with hose to drain valve of engine coolant pump.
- Undo vent line union at distributor piece.
- Open drain valve and pump coolant into engine at 0.5 bar minimum.
- Tighten union if coolant leaks out.
- Fill expansion tank until overflow edge is reached; close drain valve.
- Fit breather valve and close.
- Start engine; after running without load for 10 seconds, stop engine.
- Remove breather valve; check coolant level and top up as necessary.
- Repeat start/stop steps until coolant no longer needs topping up.
- Disconnect pump and hose; run engine unloaded some minutes and recheck level.
Tools required
- Suitable pump with hose Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Pump coolant at 0.5 bar minimum
- Fill only into cold engine
Full service-parts list: MTU 12 V 4000 G23 →, MTU 12 V 4000 G43 →, MTU 12 V 4000 G63 →, MTU 12 V 4000 G83 →, MTU 12 V 4000 Gx3 →, MTU 12V4000 G23 →, MTU 16 V 4000 G23 →, MTU 16 V 4000 G63 →
Source: MTU operator's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.