Rear heater tee pipes dump the coolant
The trucks fitted with the rear heater carry the coolant a long way back and return it through plastic tee joints in the middle of the vehicle. The specialist supplier's standing advice is to replace those tees preventively whenever the cooling system is already drained, and their reasoning is the whole entry: if one of the old plastic pipes breaks, all of the vehicle's coolant drains out, which can overheat the engine and turn a cheap plastic fitting into cylinder head work. That is why this sits at do-not-drive. Nobody is hurt by it, but the distance between the puddle and a warped head is measured in minutes of running, and the temperature gauge on a system that has already emptied itself does not necessarily rise in time to be useful. If your Montero has rear heating and you are already draining the system for something else, this is the cheapest insurance on the truck. This entry rests on one specialist supplier's standing recommendation, so it is filed at the weakest tier — the consequence it describes is severe, and it is still one source.
Gen 32001–2006Damages other partsAnecdotal
Do not driveNo lo maneje
filteredDoes not fit the vehicle you selected
Provisional matchMatched on generation, market, year and engine only. Entries marked provisional also depend on something you have not told us, so some of them will not fit your truck. Narrowing your selection removes the mark.
Anecdotal. This entry is not backed by factory documentation — treat its values and steps as a starting point, not as if they came from the factory manual.
Anecdótico. Esta entrada no se apoya en documentación de fábrica — tome los valores y los pasos como punto de partida, no como si vinieran del manual de fábrica.
Symptoms
- A large puddle of coolant under the middle of the vehicle rather than under the nose
- The temperature gauge climbing with no other warning
- The level in the reservoir keeps falling and nothing is wet at the front
- A sweet smell and steam from underneath after a run
Likely causes
- One of the plastic tee joint pipes in the rear heater circuit has broken
- A rear heater line or hose has perished along its run
- The leak is at the radiator or a front hose and not at the rear circuit
Diagnostic steps
- Park on clean, dry ground, run the engine to temperature and note where the puddle startsPoints toOne of the plastic tee joint pipes in the rear heater circuit has broken · A rear heater line or hose has perished along its runRules outThe leak is at the radiator or a front hose and not at the rear circuit
- Follow the rear heater lines along the underside from front to back looking for wet or crusted sectionsPoints toA rear heater line or hose has perished along its run
- Find the plastic tee joints in the rear heater circuit and check them for cracks and brittlenessPoints toOne of the plastic tee joint pipes in the rear heater circuit has broken
- Pressure test the cooling system cold and watch where it lets goPoints toOne of the plastic tee joint pipes in the rear heater circuit has broken · A rear heater line or hose has perished along its run · The leak is at the radiator or a front hose and not at the rear circuit
Fix paths
Replace the tee joint pipes
$$Difficulty 3/5
A small part with a large downside. Replace them as a set rather than the one that broke — they are the same age and they live in the same place.
Partsgen3-rear-heater-tee-joint-pipe
Do them while the system is already drained
$$Difficulty 4/5
The supplier's own recommendation, and the reason it is on their timing belt kit page. Almost all of this cost is access you have already paid for.
Partsgen3-rear-heater-tee-joint-pipe