Cummins V12 Series — Thermostat Housing Removal and Installation (V8-350, VT8-430)

For the Cummins V12 Series.

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Procedure

1. Removal:
2. 1. Drain cooling system.
3. 2. Loosen clamps and disconnect hose from water outlet connections on each thermostat housing.
4. 3. Loosen nuts, washers and bolts securing thermostat housing covers to cross-over pipe; remove cross-over pipe and gaskets.
5. 4. Disconnect hose between water by-pass pipe and water pump. Remove capscrews, lockwashers and flat-washers securing thermostat housing cover to by-pass pipe; lift off by-pass pipe and gasket.
6. 5. Remove remaining capscrews, lockwashers and flat-washers securing thermostat housing covers to thermostat housings; lift off covers.
7. 6. Lift off thermostat housings, gaskets and thermostats from cylinder heads.
8. 7. Remove thermostats from thermostat housings.
9. Installation:
10. 1. If thermostat housing seals were discarded, install new seal, lip first, into each housing. Press seal in until it is flush with housing.
11. 2. Insert new or tested thermostats in housing counterbore through seals.
12. 3. Position new gaskets, thermostat housings, and covers on cylinder head pads; secure with flatwashers, lockwashers, and capscrews.

Source: manual:CUMMINS Maintenance Manual Construction and Industrial Diesels 1965.pdf. Figures and steps are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.