Tools you need for coolant flush on a 2009-2018 Ram 1500

On the DS Ram 1500 this is a straightforward drain-and-fill with one twist: there is no cap on the radiator. The system fills and vents through the pressurized plastic degas bottle on the passenger side, so that bottle is both your fill point and your bleed point. The radiator has a small plastic drain plug in the lower driver-side tank; it opens with a quarter turn by hand, and it is notorious for cracking, so buy a spare before you start.

The big variable is coolant chemistry. 2009-2012 trucks came with orange HOAT (Mopar MS-9769) and 2013-up trucks use the purple OAT 10-year/150k coolant (MS-12106). They are not compatible — mixing them can gel and clog the heater core. The other thing people get wrong is air. Skipping the burp with the heater on max is the single most common cause of a cold heater and a temp gauge that climbs after a coolant change; a $40 spill-free funnel or a vacuum filler eliminates the problem.

Complete tool and parts list

Differences within the 2009-2018 generation

Tool sizes are the same across engines; only capacity and access differ. The 5.7 Hemi and early 4.7 hold roughly 14-15 quarts with block drain plugs on the sides of the block behind the motor mounts; the 3.6 Pentastar holds about 11-12 quarts and has the easiest radiator access. The 3.0 EcoDiesel holds about 15 quarts in the main loop and adds a second low-temperature charge-air cooling circuit with its own reservoir that must be checked and filled separately.

Torque specs

How the job goes

1. Let the engine cool completely. Opening a hot system will spray scalding coolant.
2. Chock the rear wheels, lift the front of the truck at the frame rails and set it on jack stands. Remove the lower splash shield or air dam if it blocks access (8/10/13 mm fasteners).
3. Slowly loosen the pressure cap on the coolant degas bottle one click to vent pressure, then remove it.
4. Position the 6 gallon drain pan under the driver-side lower corner of the radiator. Locate the plastic drain plug in the lower tank; turn it about a quarter turn counterclockwise by hand and pull to open. Many DS radiators after a replacement have no petcock — in that case release the spring clamp on the lower radiator hose with hose clamp pliers and pull the hose off instead.
5. Let it drain fully, about 8-10 quarts from the radiator alone. Squeeze the upper radiator hose to help it break vacuum.
6. For a full change, also drain the block: the 5.7 and 4.7 have plugs in the sides of the block behind the engine mounts (tight access, usually skipped unless the coolant is dirty). If you skip them you are doing a partial change — expect 60-70 percent of the fluid to come out.
7. If you are flushing, refill with distilled water only, run the engine to operating temperature with the heater on high, cool down, and drain again. Repeat until clear.
8. Close the drain plug hand tight or reinstall the lower hose with the spring clamp seated in its original mark on the hose.
9. Mix coolant 50/50 with distilled water unless you bought premix. Fill through the degas bottle. If you have a vacuum filler, use it on the bottle neck — it pulls the air out and fills in one shot with no burping.
10. Without a vacuum tool, install the spill-free funnel on the bottle, fill to the funnel, then start the engine with the heater set to max heat and high blower. Let it idle until the thermostat opens and the level drops; keep topping the funnel. Squeeze the upper hose a few times to help air move.
11. Once the level stops dropping and the upper hose is hot, shut off the engine, drain the funnel back into the bottle, remove it and set the level between the MIN and MAX marks on the bottle.
12. On the 3.0 EcoDiesel, check and fill the separate low-temperature charge-air coolant reservoir to its own marks — it is a distinct loop and does not self-fill from the main system.
13. Install the pressure cap, lower the truck, and drive it through two or three full warm-up/cool-down cycles.
14. Recheck the cold level after each cycle and top off as needed. Check the ground under the radiator for drips from the drain plug.
15. Dispose of the used coolant at an auto parts store or recycling center.

Watch out

The drain-plug location, no-radiator-cap/degas-bottle fill point, and the 2013 change from orange HOAT to purple OAT are well documented for the DS Ram 1500, but capacities vary by cab and engine and some replacement radiators lack a petcock — verify your truck's capacity and any block drain plug torque in the FSM.

Other jobs on the 2009-2018 Ram 1500

Coolant Flush on other vehicles