Cummins/Onan — Thermostat - Replace (01-33)

Maintenance

From a Cummins/Onan service manual covering: K 19, K19, KTA19, KTA19-M, KTA19G2, KTTA19, Kt19. Check it applies to your exact model before use.

Applies to: Cummins/Onan K 19, Cummins/Onan Kt19, Cummins/Onan K19 engine

Procedure

1. Open the draincock and remove the lower radiator hose to drain the cooling system.
2. Remove both upper radiator hoses and the vent line from the thermostat housing.
3. Remove by-pass tube clamp. Loosen both hose clamps and remove the by-pass tube.
4. Remove the (5) long capscrews and (1) short capscrew.
5. Remove the thermostat housing and gasket.
6. Remove the thermostats and seals.
7. Use a mallet and seal driver Part No. 3375411 to install the seal (no more than 0.51 mm [0.020] below the top of the cast edge).
8. Install the thermostat by pushing on the outer rim.
9. Install a new gasket, thermostat housing and capscrews; tighten to 45 N·m [35 ft-lb].
10. Install the by-pass tube, retainer and capscrew; tighten to 45 N·m [35 ft-lb] and hose clamps to 5.6 N·m [50 in-lb].
11. Install the two upper radiator hoses and tighten clamps to 5.6 N·m [50 in-lb].
12. Fill the cooling system and operate the engine to 70°C [160°F]; check for leaks.

Full service-parts list: Cummins/Onan K 19 →, Cummins/Onan Kt19 →

Source: Cummins/Onan service 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.

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