Drain, Flush and Refill Cooling System
RXA0070691
RXA0070692

Drain Valve and Intercooler Hose (PQ transmission shown)

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causym CAUTION: Hot coolant under pressure can cause severe burns or injury to eyes. Do not remove radiator cap while engine is still hot. Wait until engine has cooled down before removing cap.

NOTE: If COOL-GARD is not used, service interval is reduced to 2000 hours or 2 years.

NOTE: Operate cab heater during the entire flushing procedure.

1. Turn cab heater control to fully open position.

2. After allowing engine and coolant to cool down, loosen and remove filler cap.

3. Using suitable radiator tester, pressurize system to 50 to 60 kPa (7 to 8.7 psi), and inspect system for leaks.

NOTE: Connect/disconnect knob (B) opens or shuts different chambers inside radiator.

4. Turn connect/disconnect knob counterclockwise to open, taking care not to force it past stop tab, approximately one quarter turn.

IMPORTANT: To avoid possible damage to radiator, do not open drain valve (C) more than three full turns.

5. Open radiator drain valve and let coolant flow until system is empty.

NOTE: Temperature range is indicated for thermostat initial opening and fully open positions. Different part suppliers may result in slight variation from specified temperatures.

6. Remove thermostat housing (E) and thermostat. Test thermostat to verify it opens within specified temperature range.

Thermostat Opening Temperatures - Specification

Initial Opening -Temperature 80-84° C (175-182° F)
Fully Open -Temperature 94° C (202° F)

RXA0070574

Thermostat Housing (PQ Transmission)

RXA0073138

Thermostat Housing (IVT)


A-Filler Cap
B-Connect/Disconnect Knob
C-Radiator Drain Valve
D-Intercooler Hose
E-Thermostat Housing

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7. Replace housing without thermostat. Close radiator drain valve.

8. Fill system with cleaning solution.

NOTE: If not equipped with intercooler, skip to step 11.

9. Disconnect hose (D) from intercooler.

10. When coolant starts to flow from hose, connect it back to intercooler and tighten clamp.

11. Start engine and operate until system is hot again.

12. Turn engine off, drain system, allow engine to cool down again.

13. Remove thermostat housing again. Clean sealing surface, then apply sealant to new thermostat gasket. Install gasket, thermostat and housing. Tighten screws to specification.

Specification

Housing Screws -Torque 48 N·m (35 lb-ft)

14. Close radiator drain valve and add coolant until system is full.

15. Start engine and run for five minutes.

16. Stop engine, let it cool down and bring system to full again, if necessary.

17. Turn connect/disconnect knob (B) clockwise to close. Do not force knob past stop tab.

18. Install and close filler cap.

19. Start engine and bring it up to operating temperature.

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