Nissan Almera G15 is a popular car with a time-tested braking system, but even it is not immune to wear and tear. The vacuum brake booster (VBR) is a key element responsible for the comfort and safety of braking. If the pedal has become “hard” and the car brakes worse, the problem may lie there.
In this article we will look at how VUT works on Almera G15, what signs indicate its malfunction, and whether it is possible to repair the unit yourself. We'll also analyze prices for original and similar parts to help you save money without compromising safety.
Design and principle of operation of a vacuum brake booster
Vacuum brake booster Nissan Almera G15 (as on most cars with gasoline engines) uses vacuum in the intake manifold to create additional force on the pedal. This allows the driver to brake with minimal physical effort while maintaining control of the car.
Structurally, the VUT consists of:
- 🔧 Housings - a sealed chamber divided into two parts by a diaphragm.
- 🔄 Check valve — maintains vacuum in the system when the engine is stopped.
- 📏 pusher — transmits force from the pedal to the master cylinder.
- 🔗 Stock — connects the amplifier to the brake pedal.
When the driver presses the pedal, a valve connecting the atmospheric and vacuum chambers opens. The pressure difference creates additional force on the master cylinder rod, increasing braking efficiency. On Almera G15 with engines HR16DE And K4M The VUT is integrated with the master cylinder, which simplifies replacement but complicates diagnostics.
If after replacing the VUT the pedal remains “soft”, check the tightness of the vacuum hose - often the problem lies in cracks or loose clamps.
Signs of a malfunctioning vacuum booster on Nissan Almera G15
A faulty VUT manifests itself gradually, and many drivers attribute the first symptoms to “fatigue” of the brakes. However, ignoring problems can lead to complete system failure. Look out for the following signs:
- ⚠️ “Hard” brake pedal - it takes much more effort to press, especially at idle.
- 🔊 Hissing when braking - indicates air leakage through a damaged diaphragm or hose.
- 🚗 Increased braking distance — the car brakes worse, even when you press the pedal sharply.
- 🔥 Unstable engine operation — when the VUT is depressurized, air may leak into the intake manifold, which causes floating speed.
On Almera G15 with a mileage of more than 150 thousand km it most often fails check valve or diaphragm. In rare cases, the amplifier housing itself breaks - usually as a result of an accident or corrosion. Feature of the model: on cars produced in 2013-2015, there is a factory assembly defect - a loose connection of the hose to the amplifier, which leads to it jumping off.
⚠️ Attention: If the brake pedal begins to “sink” to the floor, the problem may not be in the VUT, but in the master cylinder or hydraulic system. In this case, operating the vehicle is prohibited!
- Every maintenance (every 15 thousand km)
- Once a year
- Only when problems arise
- Never checked
How to check the vacuum brake booster yourself
Diagnostics of VUT on Nissan Almera G15 can be carried out without special equipment. Here is a step-by-step algorithm:
- Checking the tightness of the system:
Stop the engine, press the brake pedal 5-6 times (to relieve vacuum in the system), then hold it down. Start the engine - if the amplifier is working properly, the pedal will “fall” down under the influence of the created vacuum.
- Air leak test:
With the engine running, press the brake pedal and turn off the engine while holding the pedal down. If after 30–60 seconds the pedal begins to “rise”, there is an air leak in the system (the check valve or hose is faulty).
- Visual inspection:
Check the vacuum hose for cracks, as well as the connection of the amplifier to the body. On Almera G15 The hose often rubs against the wiring harness mounting bracket.
For more accurate diagnosis, you can use vacuum gauge (connects to the fitting on the intake manifold). Normal vacuum in the system should be no less than 0.6–0.8 bar. If the value is lower, there is a problem with tightness.
☑️VUT diagnostics on Nissan Almera G15
Step-by-step instructions for replacing the vacuum brake booster
Replacing VUT with Nissan Almera G15 takes 1.5–2 hours and requires a minimum set of tools: keys on 10, 12, 17, flat blade screwdriver and pliers. It is more convenient to carry out work on an inspection hole or overpass.
Sequence of actions:
Disconnect the negative battery terminal.
Remove the decorative trim of the steering column (unscrew the 2 screws from the bottom).
Disconnect the brake pedal position sensor connector (if equipped).
Loosen the clamp and remove the vacuum hose from the amplifier fitting.
Unscrew the 4 nuts securing the brake master cylinder to the booster (do not disconnect the brake pipes!).
In the passenger compartment, unscrew the 4 nuts securing the amplifier to the body (access through the hole under the steering wheel).
Carefully remove the booster along with the rod, disconnecting it from the brake pedal.
When installing a new VUT, be sure to adjust the length of the rod - it should correspond to the old part. After assembly, bleed the brake system, even if you did not disconnect the pipes (air may have entered through the master cylinder).
⚠️ Attention: On Almera G15 with ABS, after replacing the VUT, the system malfunction light may come on. To reset the error, follow the sensor adaptation procedure: turn on the ignition, press the brake pedal all the way and hold for 10 seconds, then release and repeat 3 times.
Selection of spare parts: original vs analogues
Original vacuum brake booster for Nissan Almera G15 has an article number 40520-BM00A (for 2012–2018 models). Its average price in official dealers is 8,000–12,000 rubles. However, there are high-quality analogues on the market that are cheaper.
| Manufacturer | Article | Price, rub. | Features |
|---|---|---|---|
| Nissan (original) | 40520-BM00A |
8 000–12 000 | 2 year warranty, fully compatible |
| TRW | PVG1001 |
5 500–7 000 | High quality aperture, suitable for Renault with a similar platform |
| ABS | 30.5206 |
4 000–5 500 | Budget option, possible problems with the check valve |
| Febi | 23330 |
6 000–7 500 | Good value for money, comes with new check valve |
When choosing an analogue, pay attention to quality of rubber seals - cheap parts often “tanner” in the cold, which leads to depressurization. Also check the package contents: some sets do not have a check valve, you will have to buy it separately (item no. 40526-JA00A).
How to distinguish a fake of the original VUT?
Original amplifier Nissan has:
- manufacturer's logo embossed on the case (not a sticker!);
- uniform black color of plastic without smudges;
- marking of the article on a metal tag, and not on a sticker.
Counterfeits are often lighter in weight and have rougher edges.
Common replacement mistakes and how to avoid them
Even experienced car owners make mistakes when replacing VUT with Almera G15, which leads to repeated breakdowns or incorrect operation of the brakes. Let's look at the most common ones:
- 🔧 Incorrect stem adjustment — if the rod is too long, the brake pedal will “bite”; if it’s short, the brakes will become “wobbly”. The optimal clearance between the rod and the piston of the master cylinder is -
1–2 mm. - 🔩 Retightening the fastening nuts - the amplifier housing may crack. Tightening torque - no more
20 Nm. - 🚿 Ignoring bleeding the brakes - Even if the tubes were not disconnected, air could accumulate in the system through the master cylinder.
- 🔄 Using an old check valve - this is fraught with repeated depressurization. The valve is cheap (about 500 rubles), but replacing it will save time and nerves.
Another common mistake is Incorrect installation of the gasket between the amplifier and the body. On Almera G15 it is asymmetrical, and if the sides are mixed up, air may leak. It is better to replace the gasket with a new one (article no. 40528-JA00A).
After replacing the VUT, be sure to check the operation of the vacuum pump (on models with a diesel engine) - its malfunction can simulate a breakdown of the amplifier.
Cost of repairs in the service vs independent replacement
The price of replacing a vacuum brake booster at a car service center depends on the region and level of the service station. The average prices in Russia are as follows:
- 🔧 Brake system diagnostics — 1,000–1,500 rub.
- 🛠️ Replacement of VUT (without cost of spare parts) — 2,500–4,000 rub.
- 🔄 Bleeding the brakes — 800–1,200 rub.
- 🔧 Adjusting the brake pedal — 500–800 rub.
In total, taking into account the original spare parts, the repair will cost 12,000–18,000 rubles. Replacing it yourself will save up to 50%, but requires care. The main risks when doing things on your own:
- Damage to the brake pipes when removing the master cylinder.
- Incorrect rod installation leading to pedal jamming.
- Air leaks through loose connections.
If you are not confident in your abilities, it is better to entrust the work to professionals. This is especially true for cars with ABS and ESP — after replacing the VUT, it may be necessary to reset errors through a diagnostic scanner (for example, Launch X431 or Autel MaxiCOM).
FAQ: Frequently asked questions about the vacuum brake booster Nissan Almera G15
Is it possible to drive with a faulty VUT?
Technically yes, but it is extremely dangerous. Without a booster, the braking distance increases by 1.5–2 times, and the pedal becomes “hard,” which tires the driver. In addition, a faulty VUT can lead to depressurization of the brake system. We recommend replacing the part at the first sign of failure.
How often should the vacuum booster be checked?
The manufacturer does not establish regulations for VUT, but we advise checking its condition every 50,000 km or when symptoms appear (hissing, hard pedal). Particular attention is paid to cars older than 5 years: rubber seals lose their elasticity.
Is it possible to repair the VUT or only replace it?
Repair is possible if the problem is in the check valve or vacuum hose. The diaphragm or housing itself cannot be repaired - only replacement. Workshops offer “restoration” of amplifiers, but such repairs are unreliable and often lead to repeated breakdowns.
Why did the brake pedal become soft after replacing the VUT?
This is a sign of air getting into the brake system. Necessary bleed the brakes in order: rear right → front left → rear left → front right wheel. If the problem persists, check the brake master cylinder.
Is VUT from Renault suitable for Nissan Almera G15?
Yes, Nissan Almera G15 And Renault Logan/Sandero the second generation are built on the same platform, so the vacuum amplifiers are interchangeable. For example, suitable TRW PVG1001 or Febi 23330, which are used on both cars.