On the DS-generation Ram 1500, the water pump is a front-of-engine, belt-driven unit. On the 4.7 and the 5.7 Hemi the real work is getting the mechanical fan and clutch out of the way - a 36 mm thin fan wrench with a pulley holder is the tool that makes or breaks this job. Once the fan and belt are off, the pump itself is just a handful of 13 mm bolts and a gasket.
The 3.6 Pentastar trucks (2013+) skip the mechanical fan entirely, so those are the easiest. The 3.0 EcoDiesel is the outlier: the pump is buried behind charge-air and coolant plumbing and is a genuinely long afternoon. The thing people get wrong is coolant: 2009-2012 trucks use orange HOAT, 2013-on use purple OAT, and mixing them turns the coolant to sludge. Second most common mistake is not burping the air out, which cooks the engine a week later.
| Item | Type | |
|---|---|---|
| Floor jack and jack stands 3 ton minimum Raise and support the truck to reach the lower radiator hose and drain. | Safety | shop |
| Drain pan 8+ quart capacity Catches the 12-16 quarts of coolant in the system. | Required | shop |
| Hose clamp pliers Spring/constant-tension clamp pliers Releases the factory spring clamps on the radiator and heater hoses. | Required | shop |
| Fan clutch wrench 36 mm thin wrench with pulley holding tool Unthreads the fan clutch from the water pump hub on 4.7 and 5.7 mechanical-fan trucks. | Required | shop |
| Serpentine belt tool 1/2 in drive breaker bar or long-handle belt tool; 15 mm socket also fits some tensioners Rotates the spring tensioner to release the accessory belt. | Required | shop |
| Socket set, metric 8, 10, 13, 15, 18 mm 6-point, 3/8 in drive Fan shroud, pulley, water pump and bracket bolts across all engines. | Required | shop |
| Ratchet and extensions 3/8 in drive, 3 in and 6 in extensions plus swivel Reaches the lower water pump bolts behind the pulley and shroud. | Required | shop |
| Torx/hex bit set T25-T50 Torx, 5-10 mm hex Some Pentastar and EcoDiesel pump and cover fasteners use Torx or hex heads. | Required | shop |
| Gasket scraper and plastic pick Nylon or plastic scraper Cleans the timing cover sealing surface without gouging the aluminum. | Required | shop |
| Torque wrench 3/8 in drive, 5-80 ft-lb Water pump bolts thread into aluminum and must not be overtightened. | Required | shop |
| Fan pulley holding tool Pin-type or strap wrench Keeps the water pump pulley from spinning while breaking the fan nut loose. | Recommended | shop |
| Coolant funnel / spill-free filler kit Universal radiator funnel with adapters Fills and burps the system without airlocks in the heater core. | Recommended | shop |
| Shop light LED work light The lower pump bolts sit deep behind the pulley. | Recommended | shop |
| Water pump Engine-specific; comes with gasket or O-ring The replacement unit; always fit the new gasket supplied. | Parts | shop |
| Coolant 2009-2012: HOAT MS-9769 (orange); 2013-2018: OAT MS-12106 (purple). EcoDiesel uses OAT. Refill; do not mix the two chemistries. | Consumables | shop |
| Distilled water 2-3 gallons For mixing 50/50 with concentrate and flushing. | Consumables | shop |
| Thermostat and housing gasket Engine-specific Cheap insurance while the coolant is out; common failure alongside the pump. | Parts | shop |
| Serpentine belt Engine-specific length Replace if cracked or glazed while it is already off. | Parts | shop |
| Silicone gasket sealer Only if the pump ships without a gasket, per instructions Some Pentastar/EcoDiesel pumps use RTV or a dry O-ring; follow the pump maker. | Consumables | shop |
| Safety glasses and nitrile gloves Hot coolant is toxic and sprays when clamps release. | Safety | shop |
4.7 and 5.7 (2009-2012, and 5.7 through 2018 in some configs) have a mechanical fan clutch needing a 36 mm thin fan wrench and holding tool; the 3.6 Pentastar and later electric-fan 5.7 trucks do not. Gas V8 pump and pulley bolts are generally 13 mm; the 3.6 Pentastar commonly uses 10 mm and Torx-head fasteners depending on pump supplier, and the 3.0 EcoDiesel adds hex/Torx fasteners plus removal of charge-air piping. Coolant differs too: orange HOAT MS-9769 for 2009-2012, purple OAT MS-12106 for 2013-2018 and all EcoDiesels.
| Water pump to timing cover bolts, 5.7 Hemi | 21 ft-lb (28 Nm) - verify in the service manual |
| Water pump bolts, 3.6 Pentastar | verify in the service manual |
| Water pump bolts, 4.7 V8 | verify in the service manual |
| Water pump bolts, 3.0 EcoDiesel | verify in the service manual |
| Water pump pulley bolts | 21 ft-lb (28 Nm) - verify in the service manual |
| Fan clutch to water pump hub nut | Hand tight plus firm snug; verify in the service manual |
| Thermostat housing bolts | verify in the service manual |
| Radiator drain plug | Hand tight only |
Bolt sizes (13 mm typical for gas V8 pump and pulley, 36 mm fan hub nut) are accurate for the mainstream 4.7/5.7 trucks, but bolt head types vary by pump supplier on the 3.6 and 3.0 - dry-fit your sockets and confirm torque values in a FSM or AllData before final tightening.
It is a 36 mm hub nut and you need a thin fan-clutch wrench plus a tool to hold the water pump pulley still. Check thread direction before you hammer on it - applying force the wrong way can snap the pump hub.
No. On the 4.7 and 5.7 you only need the fan, shroud and belt out; on the 3.6 just the belt and some accessory brackets. The radiator stays in place on all gas engines.
2009-2012 trucks use Mopar orange HOAT (MS-9769); 2013-2018 trucks, including the EcoDiesel, use Mopar purple OAT (MS-12106). Do not mix them - if you are unsure what is in there, flush and refill with one type.
Look for coolant weeping from the pump's weep hole, a wobbling or noisy pulley when you rock it by hand, or a whine that changes with rpm. A stuck thermostat causes overheating with no leak and no bearing noise - many people replace both while the coolant is out.