How to replace the heater radiator on a Nissan Sunny FB15 without removing the dashboard: a proven method

Replacing the heater radiator with Nissan Sunny FB15 (and his twin B14) is a task that frightens many car owners due to the need to remove the dashboard. However, there is a method that allows you to do without completely dismantling the instrument panel, saving time and nerves. In this article we will analyze a step-by-step algorithm, taking into account the nuances of a specific model, tools and typical mistakes that can turn repairs into a nightmare.

Main problem heater radiator on Sunny FB15 — corrosion and leaks that appear after 8–10 years of operation. Signs of malfunction: puddles of antifreeze under the passenger’s feet, a sweetish smell in the cabin, poor heating. The manufacturer did not provide easy access to the radiator, but experienced craftsmen found workarounds. Important: the method without removing the dashboard is only suitable for standard-sized radiators - if you are installing an aluminum analogue with a modified geometry, you cannot do without disassembling the panel.

Preparation: tools and supplies

Before starting work, collect everything you need. The absence of even small things (for example, a container for draining antifreeze) can delay the process for hours. Here's the full list:

• 🔧 Set of sockets and ratchet wrenches (required) 10 mm head for stove mounts)
• 🔨 Screwdrivers: Phillips (PH2), flat (for prying off clips), short screwdriver with flexible shaft
• 🧰 Pliers and round nose pliers (for removing clamps)
• 🛢️ Antifreeze (5 l, brand must match Nissan Coolant L248 or similar CoolStream A-110)
• 🧴 Sealant for radiators (for example, Loctite 574 or ABRO 11-AB)
• 🧻 Rags, cardboard to protect the interior, container for draining coolant (minimum 5 l)
• 🔦 Flashlight with magnetic mount (lighting under the panel is critical!)

Pay special attention to the choice new radiator. Original article - 27810-4M000, but analogues from Denso (article DRH0109) or Nissens (64101). Avoid cheap Chinese copies - they often leak after 1-2 years. Also check the package: the box should contain new rubber seals and clamps.

Draining antifreeze and dismantling pipes

Start by draining the coolant. On Sunny FB15 the drain plug is located on engine cooling radiator (bottom right). Algorithm:

1. Place the car on a flat surface, raise the front part on a jack (you can do this without removing the wheels).
2. Place a container under the drain plug and unscrew it with a key 13 mm.
3. Open the cap of the expansion tank - this will speed up the draining.
4. Wait until the system drains completely (about 10–15 minutes).

Next, move on to the stove pipes. They are located behind the center console, under the glove compartment. You will need:

• Loosen the clamps on both pipes (upper and lower) using pliers.
• Remove the pipes, first placing a rag on them - antifreeze will remain in them!
• Plug the holes with a clean rag to prevent debris from entering.

Removing the glove compartment and accessing the radiator

The key is to make room for the radiator to be removed. On Sunny FB15 This is done without removing the dashboard, but it will require dismantling the glove compartment and part of the center console. Procedure:

1. Unscrew the two self-tapping screws securing the glove compartment (from below, under the plastic plug).
2. Disconnect the opening limiters (plastic latches on the sides).
3. Carefully remove the glove compartment, disconnecting the backlight connector (if equipped).
4. Remove the plastic trim under the glove compartment (held on by 3 clips).

Now you will see the stove body. The radiator is located vertically, behind a metal frame. To extract it:

• 🔧 Unscrew the 4 bolts securing the frame (head on 10 mm).
• 🔨 Loosen the latches of the stove body (2 pieces on top, 1 on bottom).
• 🧲 Use a magnet to avoid dropping the bolts into the depths of the panel!

What to do if the bolts are stuck?

If the bolts do not come out, try the following:

1. Heat them with a hair dryer (do not overheat the plastic!).

2. Use an impact driver or a socket with a lever.

3. As a last resort, drill out the bolt and cut a new thread (M6 thread).

Removing the old radiator and installing a new one

The most critical stage. The radiator sits tightly and needs to be carefully “squeezed” out of the stove body. Proceed like this:

1. Loosen the latches of the heater body (they are white, on the sides of the radiator).
2. Tilt the radiator toward the passenger side and pull it up. You may need to pry it out with a flathead screwdriver.
3. Remove the remnants of the old seal from the seat.

Before installing a new radiator:

• 🧴 Apply a thin layer of sealant to the rubber seals.
• 🔍 Check the integrity of the plastic fittings - they often break during dismantling.
• 🔄 Make sure that the arrow on the radiator (if there is one) matches the direction of antifreeze flow (from bottom to top).

A critical nuance: on some analogue radiators, the fittings may be shifted by 2–3 mm relative to the original. Before final assembly, check that the pipes fit without interference!

Assembling and refilling the cooling system

Reassemble in the reverse order, but taking into account several rules:

• Tighten the pipe clamps firmly 1.5–2 Nm - overstretching will lead to cracks.
• Before installing the glove compartment, check the operation of the heater dampers (switch the blowing modes).
• Make sure that no wires get caught under the heater body.

Fill the cooling system through the expansion tank:

1. Fill antifreeze to the mark MAX.
2. Start the engine and let it idle for 5-7 minutes.
3. Add antifreeze to the level (it will go into the system when it warms up).
4. Check for leaks and air in the system (the stove should blow hot air).

Common mistakes and how to avoid them

Even experienced craftsmen make mistakes when replacing a stove radiator with Sunny FB15. Here are the most common:

Error	Consequences	How to avoid
Incomplete drainage of antifreeze	Contamination of the new radiator, air pockets	Drain the coolant through the plug on the cylinder block (key on 14 mm)
Re-tightening of pipe clamps	Cracks in fittings, leaks	Use a torque wrench or tighten by hand with moderate force.
Ignoring damper checks	Inoperative airflow modes after assembly	Check the operation of the flaps before installing the glove box
Using low-quality sealant	Corrosion of rubber seals	Use only specialized sealants for cooling systems

Another common problem is debris getting into the cooling system. If you do not flush the system before replacing the radiator, particles of rust or old sealant may clog the new radiator. For washing, use special products (for example, Liqui Moly Kuhler-Reiniger) or distilled water with citric acid (100 g per 5 l).

⚠️ Attention: If after replacing the radiator the heater only operates at maximum fan speed, check the fuse F10 (10A) in the block under the hood. It is responsible for the stove motor resistor and can burn out if there is a short circuit during operation.

Is it worth contacting the service?

Replacing the heater radiator with Nissan Sunny FB15 without removing the torpedo it takes 4–6 hours (depending on experience). The service department asks for this work from 8,000 to 15,000 rubles, plus the cost of spare parts. If you are not confident in your abilities, turning to professionals is justified in the following cases:

• 🔧 You do not have a specialized tool (for example, heads on 10 mm with extension cord).
• 🕒 You are limited in time - mistakes in a hurry are more expensive.
• 🔍 The radiator is leaking due to corrosion of the air conditioner pipes (the system requires vacuuming).

However, if you are willing to spend a day on repairs and follow the instructions, replacing it yourself can save up to 70% of the cost. The main thing is to take your time and check each stage. For example, before final assembly, turn on the stove in all modes to make sure there are no extraneous noises (they may indicate a tool hitting the dampers).

⚠️ Attention: On cars with air conditioning, when dismantling the heater radiator, you can accidentally damage the refrigerant pipes. If you hear a hissing sound or see an oily liquid, stop work immediately and contact service! A freon leak requires professional repair.

FAQ: Frequently asked questions about replacing a heater radiator

Is it possible to replace the heater radiator without draining the antifreeze?

Technically possible, but highly not recommended. Even if you pinch the pipes, when you remove the radiator, antifreeze will still spill into the cabin through the fittings. In addition, without draining the coolant, air will remain in the system, which will lead to poor heating. If you still decide to take the risk, use a vacuum pump to pump the liquid through the expansion tank.

What antifreeze should I fill in after replacing the radiator?

For Nissan Sunny FB15 suitable for standard antifreeze Nissan Coolant L248 (green) or its analogues: CoolStream A-110, Sintec Unlimited G12+. The main thing is not to mix different types (for example, green and red). If you do not know what was previously filled, rinse the system with distilled water and add new antifreeze.

Why does the heater blow cold air after replacing the radiator?

There are several reasons:

1. There is air left in the system. Solution: warm up the engine with the expansion tank cap open, periodically squeezing the pipes.
2. Thermostat is faulty. Check the temperature of the upper radiator hose - if it is cold, the thermostat is stuck.
3. The new radiator is clogged. This happens with cheap analogues. Rinse it with reverse flow of water.

Do I need to remove the battery to replace the heater radiator?

No, it is not necessary to remove the battery. However, it is recommended to disconnect the negative terminal to avoid short circuits when working with metal tools near wiring. If you have a self-powered alarm installed, before disconnecting the battery, find out the code to reset it.

Is it possible to install a heater radiator from another Nissan model?

Theoretically, radiators from Nissan Almera N16 (article 27810-4M010) and Primera P12 (27810-4M005), but problems may arise:

• Differences in the location of the fittings (the pipes will require modification).
• Other dimensions of the case, due to which the radiator may not fit into place.

It’s better not to experiment and take a radiator designed specifically for Sunny FB15/B14.