Karcher k7 DIY repair

Karcher is a quality technique for professional cleaning or household cleaning.

But even high-quality equipment can fail with constant or improper use. In the article, we will talk about the principle of operation of devices, weak points of technology, main breakdowns and their causes, so that in case of collision with any of them you can know what to do.

Despite the fact that Karcher sinks are the leader in their industry, they also fail. If the Karcher sink does not turn on one day, you do not need to panic, in most cases the problem is not serious and can be easily corrected. Some of the most popular reasons why the sink may not turn on are:

1. Stuck control valve piston. This problem leads to the fact that after turning the control knob, the device still does not turn on, since the piston does not move and cannot reach the desired activation lever.
2. Breakdown of the relay.
3. Piston breakage.

In 90% of cases, if the Karcher does not turn on, the reason is the sticking of the valve. Typically, this problem occurs due to the fact that it is through the valve that the detergents pass. As a result, it stops responding to switching on.

You can repair the system yourself if you have basic technical and electrical skills. Sticking of the valve can be due to the constant passage of detergents through it, which are supplied through the plastic nipple.

To fix the problem, you need to disassemble the sink body. This will require a screwdriver, hexagons and sprockets, or you can use a screwdriver to make the process go faster. Be sure to check that there is no water inside the sink and unplug it.

First you need to disassemble the case, then remove the clamp that secures the motor. The valve we're interested in is hidden under a plastic nipple, but you can't get it, you can only check the valve travel. To remove the valve itself, you need to open 4 hexagons on the body, disconnect it, remove the electrical block and divide the lower part. You will see the valve tip pressing against the disconnect end of the circuit, which will prevent the sink from turning on.

Now you need to clean its seat, wipe it with grease, and if the spring is bent, unbend it. However, if you do not have technical skills, it is best to contact a service center.

To reduce the risk of such a problem in the future, you should buy a foam lance - the foam is much lighter than the stringy detergent.

To understand what exactly broke and why the sink stopped working, you need to understand how Karcher works. The operation of this car wash is based on high-pressure technology, water is supplied under pressure, such a device allows you to cope with any pollution as quickly as possible and with low labor costs, with its help you can wash a car or put in order a site.

The design of this device is based on a powerful synchronous electric motor, its power can reach 3 kW. The motor rotates against the swash plate attached to the shaft. In this case, the plunger is in contact with the washer, making translational movements, and when the plunger moves to the lowest point, water is supplied through the inlet valve. And when the plunger moves up, overpressure builds up and the high pressure outlet valve opens.

Modern models of Karcher sinks are equipped with water-cooled electric motors, which makes it possible to increase the service life of the engine and prevents it from overheating during operation. Accordingly, the sink can work longer without interruptions, which means that its productivity also increases.

German-made household mini-washers are usually equipped with plastic or aluminum valves, which makes the device cheaper, but reduces the functionality of the device. Sinks with plastic or aluminum valves cannot work for a long time without overheating; they often require recharging. The average operating time without interruption for such devices is 60 minutes.

Professional pressure washers use a brass or stainless steel pumping unit. Accordingly, the operating time without interruption for this sink will increase. Some professional-type models are capable of working several shifts without interruption.

In order for the minisinks to break less often, that you need to operate them correctly, the device should not be left for long breaks with high pressure in the system. This will create additional stress and lead to premature wear of the elements. It is also recommended to use an automatic shutdown device - it is installed in all modern car washes and can save up to 20% of electricity.

Speaking about the safe operation of the sink, you also need to figure out which oil to fill in Karcher. It is recommended to use only high-quality oil in order for the sink to work stably and without interruptions, as well as to prevent its premature breakdown. It, like fuel, influences the life of the sink and the result during the operation of the generator. During production, the manufacturer fills in the necessary oil on his own and usually no replacement is required - the amount of oil is enough for the entire life of the mini-washer. If we are talking about a household model, then a really factory filling should be enough. But when using professional washers, the need to change the oil sometimes arises.

Depending on the design features of the model, lubricating oil can be poured separately, into a special reservoir, and together with fuel when refueling. The viscosity index of the oil and its marking must be taken into account. Viscosity indicates the time of the year in which the oil can be used. There are winter, summer and universal varieties, universal ones include SW-20, 10W-40, 10W-50, 3W-30 and many others. In winter, the viscosity of the oil should be 0-20W, and in summer - more than 20W.

You can use multi-purpose oils such as CD or SG, they are suitable for any time of the year, for any type of fuel. Otherwise, S-marked oils should be used for diesel generators.

The sink began to work intermittently and there is no pressure. What to do? How to fix a Karcher sink with your own hands?

The reason you described may lie in the incorrect operation of the water pump. To fix it, you need to: first of all, turn off the power supply, then remove the plastic casing (case) and get close to the pump itself. The pump should be removed and disassembled in detail, this is the only way you can determine the cause. Wear of O-rings and much more visually immediately after disassembly, all defects are clearly visible. Often, solid particles get into the water, which can disrupt the operation of the pump. When the pump is disassembled

when all the parts are removed, they need to be put in warm water with citric acid so that all the old grease goes away. Then wipe everything thoroughly and replace every part with defects.

You write that there is no pressure, most likely the reason is in this bypass valve

But I will immediately emphasize that there are quite a few models of Karcher high-pressure washers, the reasons for breakdowns are even more, because the technique is rather complicated.

Correct diagnosis is 90% of the repair success.

The valve that I wrote about above can stick, the reason is dirt.

Sometimes it is enough just to rinse it, clean it and lubricate it, this is a collapsible unit, it is better to take a branded Karcher lubricant, in our case we need silicone lubricant.

We remove the casing (usually it is 8 bolts), put the device lying down with the wheels up.

Next, we remove the pipe (plastic), here you need a hex key, it is held on three bolts.

We take out the valve itself with pliers.

Examined, rubbed, want to disassemble into components.

Lubricated, assembled the sink in reverse order and started it.

If everything is in order, then we have managed with small efforts (investments); if not, we change the valve to a new one.

When reassembling, check the mesh filter, it is located in the branch pipe (see above), the mesh may be torn due to this, dirt gets on the valve.

The filter is only cleaned, it is not repaired, if it is torn, we buy a new one and replace it.

If there are interruptions in work in Karcher, as you correctly noticed this may occur due to a loss of pressure, then the water supply stops until the device reaches the required pressure and so on constantly.

As I noticed, there can be several reasons, at least two.

You should not go straight into the water pump, first you need to look at the contamination of the filter and the water supply system in general, it is quite possible that there is simply no access to water.

If everything is normal with pollution, or rather everything is clean, then check the tightness of the system, there is a possibility that the pressure is being released due to water leakage from the system, perhaps the hose just cracked or the cuff is leaking.

If the first two examinations did not reveal anything, then the water pump is diagnosed and repaired.

They call it correctly - pump.

I personally recommend installing a new pump assembly, due to the fact that in the old one there may be a production and replacement of a repair kit will not work.

Yes, and at a price there is not much difference, so the pump costs from 2000 to 5000 steering wheels, if assembled, and repair kits from 1000 to 4000 rubles.

To choose a pump, you need to know the Karcher model, and in some cases, how it looks.

Here is an example of replacing the pump for the karcher k 4.75 model