Sedan Nissan Cefiro The A33 generation, released in the late 90s, remains one of the most elegant and reliable cars in its class. However, like any Japanese car of that era, it has its Achilles heels, one of which is body corrosion. When inspecting and repairing, special attention should be paid to rapids, since they take the brunt of reagents, moisture and mechanical damage during operation.
The situation is aggravated by the fact that the factory body protection is A33 Over time, it loses its properties, and the metal begins to rust from the inside. The owner is faced with the need to either restore old elements or look for quality alternatives. In this article we will look at what protection options exist, how to install them correctly and what to do to ensure that your sedan will serve for many years without serious problems with the metal.
Design features and weaknesses
Thresholds on Nissan Cefiro A33 They are not just a decorative overlay, but an important strength element that ensures torsional rigidity of the body. They are made of stamped steel and welded to the side members and the bottom. The main problem is that the design provides for internal cavities, which are almost impossible to properly treat with anti-corrosion agent after assembling the car on the assembly line.
Over time, water entering through drainage holes or chipped paint will stagnate inside. This causes corrosion to start from the inside and spread outwards. By the time rust becomes visible from the outside, the metal is often completely destroyed. Particularly vulnerable are the areas under the rubber door seals and the areas attached to the subframe.
- 💧 Moisture accumulates in the drainage holes if they are clogged with dirt or ice
- 🔨 Mechanical impacts from stones destroy the protective layer of paint and epoxy primer
- ⛈️ The use of aggressive reagents in winter accelerates electrochemical corrosion of metal
Considering the age of most specimens Cefiro A33 in the secondary market, the condition of the thresholds often becomes a decisive factor when buying or selling a car. Even minor rust can quickly turn into a hole-through hole if not addressed promptly. It is important to understand that local cleaning and painting of the outside often only masks the problem without radically solving it.
Types of protection: from factory linings to power elements
There are many solutions on the market to protect thresholds Nissan Cefiro. The simplest option is plastic or metal linings that are attached over the standard threshold. They act as a shield, absorbing impacts from shoe soles and gravel. However, such elements do not increase the rigidity of the body and do not stop corrosion if it has already begun.
A more serious solution is to install enhanced thresholds made of thick steel. They replace the original elements completely or are placed on top of them from the inside. Such parts often have additional stiffeners and thicker metal, which makes them virtually indestructible under normal operating conditions.
- 🛡️ Polyurethane linings: easy installation and scratch protection, but low strength
- ⚙️ Metal linings: high strength, but require high-quality anti-corrosion treatment
- 🔧 Power thresholds: maximum body protection and improved geometry in case of serious accidents
The specific type of protection you choose depends on your goals. If the car is used in the city, good pads are enough. For a car that drives on bad roads or is used as a workhorse, it is strongly worth considering the option of completely replacing it with reinforced power elements.
- Factory pads
- Reinforced metal thresholds
- Polyurethane
- I don't use protection
Removal and preparation process for installation
Before starting any work to replace or strengthen the thresholds, it is necessary to dismantle the old elements. On Nissan Cefiro A33 This is a procedure that requires patience and care, as old bolts often become stuck and the metal can be brittle due to corrosion. You will need a set of open-end and socket wrenches, as well as a tool for cutting metal if the thresholds are rotten.
First, remove the plastic trim (if any) and rubber door seals. Next, unscrew the bolts securing the threshold to the bottom and arches. It is often necessary to use a penetrating lubricant such as WD-40 or analogues to unscrew rusted hardware. If the bolts are broken, you will have to use a grinder or a screwdriver with a drilling attachment.
☑️ Preparation for replacing thresholds
It is important to take your time during the dismantling stage. If the metal of the threshold is too damaged, it may simply crumble when you try to unscrew the fasteners. In this case, it will have to be cut into pieces. Be sure to check the condition of the side members and the bottom at the attachment points, as corrosion often spreads to them.
Anti-corrosion treatment and installation
High-quality anti-corrosion treatment is 90% of success in preserving the body. After installing new or restored thresholds, special compounds must be applied. Ordinary paint will not help here, since it does not have sufficient adhesion and elasticity. Use specialized mastics, bitumen compounds or liquid plates.
Pay special attention to the internal cavities. Before closing the thresholds, you need to treat them from the inside using a hose and sprayer, applying the composition Molykote or similar wax or oil based materials. These products are able to penetrate the micropores of metal and displace moisture.
- 🧪 Bitumen mastic: creates a durable protective layer, but is heavy in weight
- 🌊 Liquid rubber: elastic and perfectly hides minor surface defects
- 🛢️ Wax compositions: ideal for internal cavities, as they do not harden over time
When welding new elements, it is necessary to follow the technological process. Welding points must be thoroughly cleaned and treated with welding primer. After the joint has cooled, a layer of epoxy primer is applied, followed by a finishing coat. Never skip the priming step, as the metal will begin to rust right under the paint.
What are the dangers of poor welding?
If the seam is made poorly, moisture will accumulate at the junction of the metal and the new part. This will lead to the formation of “through” corrosion, which will be very difficult to notice at an early stage.
Before applying the mastic, be sure to dry the inner cavity of the threshold with a hairdryer or heat it with a blowtorch (carefully!) to remove all moisture.
Comparison of factory and reinforced options
For clarity, let’s compare the main characteristics of standard thresholds and reinforced analogues available on the market. This will help you make an informed choice based on your budget and operating conditions. Nissan Cefiro A33.
| Parameter | Factory threshold | Reinforced metal | Polyurethane pad |
|---|---|---|---|
| Metal thickness | 0.8 - 1.0 mm | 2.0 - 3.0 mm | N/A (plastic) |
| Corrosion protection | Low (after 5 years) | High (during processing) | Average |
| Effect on body rigidity | Basic | Increased | Missing |
| Cost | Average | High | Low |
As can be seen from the table, reinforced thresholds win in all respects except price. However, if you plan to drive the car for a long time, investing in power elements will pay off without the need to constantly patch holes in the body. Polyurethane overlays are good as a temporary solution or for cars that are kept in a garage.
Typical mistakes during repair and maintenance
Many owners make mistakes by trying to save money on repairs or using the wrong materials. One of the most common problems is ignoring drainage holes. If you installed new rocker panels or trims but didn't check the water drain holes, you will create a "thermostat" for moisture inside the body.
Another mistake is using sealants instead of anticorrosive. The sealant does not breathe and peels off over time, leaving the metal unprotected. Moisture penetrates under the sealant layer and begins to rot the metal that you cannot see.
⚠️ Attention: Never cover the drainage holes in the thresholds with additional covers or sealant. This is guaranteed to lead to rapid rotting of the body from the inside.
You should also avoid using acidic primers without a subsequent topcoat. Acid in the soil eats away rust, but if an insulating layer is not applied on top, the metal will begin to oxidize even faster due to contact with oxygen and moisture.
The correct processing order is: Cleaning off rust -> Priming with epoxy -> Applying mastic/liquid rubber -> Finish painting. Skipping any step reduces the service life of the protection significantly.
FAQ: Frequently asked questions
How much does it cost to replace door sills on a Nissan Cefiro A33?
Costs vary greatly depending on the region and the type of parts selected. Factory used thresholds can cost from 3,000 to 5,000 rubles per pair, while reinforced new parts will cost 15,000 to 25,000 rubles. Replacement and painting work will add another 10,000 - 15,000 rubles to this amount.
Is it possible to simply weld a hole in the threshold?
Technically this is possible, but without complete stripping to bare metal and high-quality anti-corrosion treatment from the inside, such a patch will not last long. Rust will continue to creep around the seam. It is recommended to cut out the rotted area and weld in a new insert followed by processing.
Do I need to remove the doors when replacing thresholds?
Preferred, but not required. Removing the doors simplifies access to the edges of the sills and allows for high-quality welding of the joints. However, if you work carefully and use spot welding, you can avoid removal by covering the doors with masking tape for protection.
What anticorrosive agent is best to use for thresholds?
For external surfaces, bitumen mastics or liquid rubber are best suited. For internal cavities, wax compounds (for example, Tectyl, Dinitrol) or oil-based anti-bark liquids, which are able to displace moisture and do not harden for a long time, are ideal.
How often should the thresholds be checked?
It is recommended to carry out a visual inspection of the thresholds and check the drainage holes at least once a year, preferably before the onset of the winter season. This will allow you to detect the onset of corrosion in time and prevent serious damage.