Changing the brake system on a car Nissan Almera The G15 generation requires a careful approach, especially when it comes to the rear axle. Unlike the front calipers, where the piston was simply pressed in, here the design requires preliminary twisting of the mechanism. Ignoring this nuance will lead to mechanical damage to the piston or sealing rings, which will entail costly repairs.
Replacement procedure rear pads takes from 40 to 90 minutes depending on the experience of the technician and the condition of the fasteners. If rust has stuck to the guides or drum, the time may increase significantly. The main design feature of the Almera G15 rear caliper is the need to rotate the piston when pressing, otherwise it will not sit in place.
Tool preparation and wear diagnostics
Before lifting your car on a lift or jack, you need to make sure that you have all the necessary tools. The lack of special tools often becomes the reason for failure during independent repairs. You will need a standard set of wrenches, including 12, 14 and 17 millimeter sockets, as well as a specialized tool for compressing the piston.
It is best to inspect the condition of the brake system immediately after removing the wheel. Pay attention not only to the thickness of the friction lining, but also to the condition of the caliper guides. If they have visible damage or dirt, they must be cleaned and lubricated with special silicone grease before installing new parts.
To ensure quality work, prepare the following items:
- 🔧 DOT-4 brake fluid (to add to the reservoir if necessary)
- 🧽 Oxygen cleaner (WD-40 or equivalent) for treating bolts
- 🛠️ Special ratchet wrench for rotating the caliper piston
- 🧴 Graphite or silicone grease for guides and brackets
If you notice that the brake fluid in the reservoir is at the maximum level, it is better to pump out some of it with a syringe before starting work. This will prevent overflow and contamination of the body during the reverse stroke of the piston.
☑️ Replacement tools
Removing the wheel and brake caliper
After fixing the car on a flat surface and raising it with a jack, unscrew the wheel bolts. Remove the wheel and begin unscrewing the caliper guides. They are usually located at the top and bottom of the bracket and require a 14 or 17mm wrench depending on the model year.
It is important not to damage the brake hose when removing the caliper. Do not allow it to hang suspended on a spring or spring. It is best to hang it on a wire or hook to eliminate tension. This is especially true for the model Nissan Almera, where the hose length may be short.
After removing the caliper, you need to carefully place it on a clean rag or hang it so as not to damage the hose. The old pads can be immediately removed from the bracket, but this must be done carefully so as not to scratch the brake disc. Inspect the bracket for scoring or corrosion that could be preventing the new pads from moving.
If the guide bolts cannot be removed, use a penetrating lubricant and allow it to work. Hitting the head of the bolt firmly with a hammer may help, but requires care to avoid stripping the threads.
Removing the brake drum and cleaning the mechanism
The rear axle of the Nissan Almera G15 uses a drum structure, which often causes difficulties during dismantling. If the drum cannot be removed by hand, it may be stuck to the hub or the hand brake mechanism is not adjusted. In this case, you cannot hit it directly, as you can damage the seats.
Make sure the handbrake is fully lowered before removing the drum. If the drum is clamped, it is necessary to adjust the cables or use the technological slot in the rear cover to remove the pads. This is something that beginners often miss when they try to knock the drum with a hammer, which leads to cracks.
After removing the drum, thoroughly clean the internal cavity of brake dust. This dust is toxic and harmful to the lungs, so use a respirator and wet cleaning or special brake cleaner. Do not use compressed air to blow out dust as it will fly everywhere.
⚠️ Warning: Brake dust contains asbestos fibers (in old pads) or ceramic particles, which are extremely dangerous if inhaled. Wear a respirator and safety glasses.
How to remove a stuck drum?
If the drum does not come off, apply penetrating lubricant to the hub bore and wait 15-20 minutes. Then use a rubber mallet to gently tap the inside of the drum through the hole in the wheel rim. Never hit the end of the drum with a hammer - it may crack.
The process of replacing pads and adjusting the handbrake
Installing new pads begins with preparing the hand brake mechanism. If you are only replacing the pads, make sure that the release mechanism is not jammed. Insert the new pads into the bracket, having previously lubricated the contact points with a special high-temperature grease.
The key is to install the caliper piston back into the housing. To do this, you need to not only press it in, but also turn it clockwise at the same time. If you try to push it in without rotating, the threaded part of the piston will be damaged. Use a special wrench or set of wrenches to compress the pistons.
After installing the pads and assembling the caliper, check the free play of the piston. It should move smoothly without jamming. If the piston doesn't click into place, you may have misadjusted the handbrake mechanism and the shoes are still pressed against the drum.
- 🔩 Make sure the guides are lubricated and move freely
- 🔄 Rotate the piston clockwise when pressing
- 🧹 Clean the seats from old dirt and rust
- Every 30,000 km
- Every 50,000 km
- Only when worn
- I don't know the exact mileage
Drum installation and final assembly
Once the new pads are installed and the piston is pressed in, you can begin installing the brake drum. It should fit onto the hub without effort. If the drum is sticking, check to see if the handbrake springs are sticking out or caught on the new shoes.
Secure the drum with a screw or nut (depending on the configuration) and install the wheel. Before lowering the vehicle to the ground, tighten the wheel bolts lightly to prevent them from becoming distorted by the weight of the vehicle. You need to lower the car smoothly, controlling the position of the wheel.
After installing the wheel, tighten the bolts with a torque wrench to the torque specified in the manual (usually about 100-110 Nm). This is critical to preventing the wheel from coming loose while driving. Do not use impact wrenches for final tightening as this may strip threads or warp the disc.
It is important to check the operation of the handbrake. Raise the car on a jack, tighten the handbrake and make sure that the wheels are locked. Then release the handbrake and check that the wheels rotate freely. If there is resistance, the handbrake mechanism may need adjustment.
Before final tightening of the wheel bolts, check that the disc rotates freely and that there are no extraneous sounds.
Selection of spare parts and pad brands
Spare parts market for Nissan Almera G15 offers a huge selection of options, from original parts to high-quality analogues. Original (Nissan) pads provide a perfect fit, but are often overpriced. Many owners are switching to trusted brands that offer better value for money.
When choosing analogues, pay attention to the composition of the friction mixture. Ceramic pads produce less dust and are quieter, but can be more expensive. Metal alloys are more wear-resistant, but can wear out the brake disc more. Semi-metallic compounds are best suited for urban use.
The table below shows popular manufacturers and their characteristics:
| Brand | Type | Pros | Cons |
|---|---|---|---|
| Nissan (OEM) | Original | Perfect compatibility | High price |
| TRW | Analogue | High quality, durable | Can be noisy |
| Textar | Analogue | Soft operation, little dust | Average resource |
| Ferodo | Analogue | Stable braking | Rapid disc wear |
You should not save on brakes by choosing the cheapest options without a well-known marking. Low-quality pads can lead to overheating, loss of braking efficiency and even wheel seizure. Always check for quality and packaging certificates.
Common mistakes and their consequences
One of the most common mistakes is ignoring the condition of the caliper guides. If they are not cleaned and lubricated, the caliper will stop moving, causing uneven pad wear and overheating of the brake system. This can result in brake fluid boiling and loss of brakes.
Another mistake is incorrect installation of springs and clamps. If the spring is installed crookedly, the pad will spontaneously press against the disc, creating unnecessary resistance and heat. This can also lead to rapid wear of the pads and the appearance of an unpleasant burning smell.
Forgetting to check the brake fluid level after changing is another common mistake. If the fluid level is too low, air can enter the system, reducing braking performance. Always check the level before driving.
⚠️ Caution: Never leave the caliper piston in the extended position without installing the pads. This may cause it to fall out and damage the seals.
Regularly checking and lubricating the caliper guides will prolong the life of the brake system and ensure safe braking.
Testing after replacement
After all work is completed, a test drive should be carried out. Start driving at low speed and gently press the brake pedal several times. This will allow the pads to rub against the disc and remove any possible air pockets. If the brake pedal is soft, there may be air in the system.
Pay attention to the car's behavior when braking. The car should not pull to the side, and the pedal should be hard and responsive. If you feel vibration or hear grinding noises, stop immediately and check the pads for proper installation and the condition of the rotor.
In the first 100-200 kilometers, avoid sudden braking and emergency stops. The pads need time to completely grind in. Hard braking on new pads can cause overheating and carbon deposits, which will reduce braking performance.
If everything went well, you can return to normal operation. Be sure to check the brake fluid level after a few days, as it may drop slightly after the pads are ground in.
FAQ: Answers to frequently asked questions
Do I need to change brake discs when replacing pads?
Not always. If the thickness of the disc exceeds the minimum allowable and there are no deep grooves or cracks on it, it can be left. However, if the disc is worn by more than 1-2 mm, it is better to replace it along with the pads to ensure maximum contact.
How can you tell if the rear pads are worn out?
Wear is indicated by squeaking when braking, vibration of the steering wheel or decreased braking efficiency. You can also visually assess the thickness of the friction lining through the hole in the caliper or drum.
Is it possible to replace the pads without removing the drum?
No, on the Nissan Almera G15 the rear pads are located inside the drum. To replace them, it is necessary to remove the drum, which requires preliminary adjustment of the hand brake or the use of a special tool to remove the pads.
How long does it take to replace rear pads?
For an experienced technician, replacement takes about 40-60 minutes on one side. A beginner may need 1.5-2 hours, especially if there are problems with stuck parts or adjusting the handbrake.
What to do if the piston does not press in?
Check whether the handbrake mechanism is twisted. The piston must be rotated clockwise when pressed. If it still won't go, the seal or threads may be damaged and the piston or caliper will need to be replaced.