Under Load The Hammer Does Not Drill

There is nothing eternal. And the most reliable Bosch rotary hammers begin to break over time. But any malfunction can be repaired with your own hands, if you have a detailed manual on the implementation of repair work. Below we offer you a guide for troubleshooting malfunctions in Bosch rotary hammers and a technique for resolving them.
The main causes of breakdowns are:

  • sloppy work with the tool;
  • improper storage of the hammer;
  • heavy loads when working on working bodies when chiselling or drilling;
  • instrument overheating;
  • long work without a break;
  • failure to comply with the timing of maintenance.

Conventionally, faults can be divided into mechanical and electrical.

Next, we consider malfunctions by their affiliation, dividing them into malfunctions by mechanical and electrical parts.

Mechanical malfunctions of the Bosch rotary hammer

When mechanical malfunctions occur in the operation of the tool, an unpleasant unpleasant sound appears, sparking increases in the collector area, a burning smell appears, the tool is excessively heated, its power decreases depending on the duration of work and the effect on the material.

We consider all the malfunctions on the diagram of the Bosch 2-26 hammer drill. Other models, such as Bosch 2-20, 2-24, differ in the design of the intermediate shaft, the installation of various drunk bearings.

The puncher stops hammering, but drills

The hammer drill does not hammer under load or in idle mode for the following reasons:

  • the rubber rings of the hammer, hammer, piston are worn out;
  • the cage of the rolling bearing has collapsed;
  • the cylinder collapsed, the striker of the barrel of the percussion mechanism;
  • cut off the splines of the clutch mounted on the countershaft;

The punch stopped drilling, but hammering

The main reasons for which the hammer drill hammer, but does not drill, are:

  • the force of the conical spring weakened, pressing the clutch;
  • the locking roller does not fix the large gear of the shaft shaft;
  • Does not hold the mechanism for fixing the tool in the barrel;
  • The hammer drill does not hammer or drill.

The main reasons for which the hammer drill does not hammer and does not drill are:

  • cut teeth on the small gear of the rotor or on the large gear of the intermediate shaft;
  • the hammer motor does not work;
  • there is no power to the rotary hammer motor.

Now, first things first

Consider options in which the hammer drill does not hammer, but drill

Wear of rubber rings on the hammer, hammer, piston.

This reason appears gradually, as the rubber rings wear. At first, the blow weakens, then disappears altogether.

The malfunction is eliminated by replacing the indicated rubber rings with new ones.

For any repair of perforators, its components, all rubber products are subject to replacement.

Under Load The Hammer Does Not Drill

Remkomplekt rubber sealing rings to the Bosch 2-26 puncher

Collar of a rolling bearing collapsed (drunk bearing)

When the drunken bearing pos.

It is eliminated by complete replacement of the rolling bearing.

Friction bearing

Collapsed cylinder, drummer, hammer of the barrel of the shock mechanism

There are cases when a drummer bites in the cylinder pos. 26, which leads to the destruction of the cylinder and the inability to create air pressure in the barrel of the percussion mechanism. And the second reason: the destruction or breakage of the striker pos. 28, leading to the curvature of the part and the impossibility of transmitting a shock pulse.
Failures are eliminated by the complete replacement of failed parts.

The hammer is stuck in the piston, the destruction of the piston

Clipped the clutch slots pos.67 mounted on the intermediate shaft

The malfunction is eliminated by repair of the clutch or its complete replacement.
During the repair, the clutch teeth are sawn in the clutch. To fix this defect, a round file and a drill are used. The clutch is clamped in the hand, and the tooth profiles are straightened with a drill with the corresponding file. Similarly, the splines are finalized on the intermediate shaft.

Video: Under Load The Hammer Does Not Drill

Restoration of teeth of a clutch of an intermediate shaft

Consider options in which the hammer drill drills but does not hammer

The force of the conical spring pressing the clutch has weakened

When the spring pressure force of pos. 50 decreases, the clutch slips on the countershaft without transferring rotation from the small spur gear to the large gear of pos. 22 of the barrel shaft pos. 821 of the impact mechanism. By the way, on different Bosch models, clutches are arranged differently.

Details of the transmission unit of the moment of rotation and translational impulse

The lock roller does not fix the large gear of the shaft shaft

The large gear pos.22 is mounted on the shaft shaft pos.01 with the roller pos.88, is pressed against the shaft shoulder by a conical spring pos 80 and fixed by the lock ring pos.85.

The reason may be a weakening of the force of the conical spring pos. 80, the destruction of the retaining ring pos. 85, the loss of the locking roller pos. 88.

Gear pos.22 on the shaft pos.01 of the barrel pos.821 of the shock unit

The drill does not hold the mechanism for fixing the tool in the hole

Bosch rotary hammers use two types of chucks: SDS-plus and SDS-max. The difference in the design of the locking mechanism.

The reason is the wear of the antennae of the raster sleeve of the cartridge, which leads to the impossibility of transmitting a shock pulse to the working tool of the punch.

Bosch 2-26 Hammer Tool Shanks

Consider options in which the punch does not drill and hammer

Cut the teeth on the small gear of the rotor

There is a rotation of gears with cutting teeth on one of them, often on a small one.

When the working tool is stuck and the clutch malfunctions, the teeth of the gears wear or completely break on the perforator shaft and the intermediate shaft.

In this case, the rotor or the large gear of the intermediate shaft changes completely.

Bosch 2-26 rotary hammer rotor with cut-off slots

The hammer motor does not work

The reasons for a non-working electric motor can be:

  • short circuit in the rotor, stator;
  • destruction of carbon electrobrushes;
  • weakening of the mounting of the brush holders;
  • burnout of lamellas on the rotor manifold;
  • breakage of the rotor or stator windings.

The listed malfunctions are eliminated by repair (manual winding of the windings, replacement of the collector and soldering of the leads of the windings) or by replacing the rotor, stator, carbon brushes with new ones.
The main part of the malfunctions of the electrical part of the Bosch 2-26 rotary hammer is confirmed by increasing sparking in the collector area.

The length of serviceable electrobrushes can not be less than 8 mm. When replacing one brush, the second should change automatically.

The rotor or stator windings can be rewound independently to their own hands at home.

Burnt Rotor Manifold Bosch Rotary Hammer

No power on Bosch rotary hammer motor

The cause of this malfunction is a break in the wire that supplies power to the electric motor. Most often, a break occurs at the place where the cable enters the hammer drill. The wire should be replaced with a new one or repaired. The fault can be determined using a tester. If there is no tester, the malfunction can be found using the power phase and a screwdriver with a neon indicator lamp. By connecting in turn the power wires, at the other end, using a neon screwdriver, determine the presence or absence of a phase.

The punch button does not work. It is determined by a short circuit tester.

Most often, a punch of the punch button causes a short circuit in the filter capacitor. It is best to replace the button with a new one.

Power cord pos. 5 at the tool inlet

General electrical malfunctions of the Bosch 2-26 rotary hammer

The failure of the puncher in the electrical part is accompanied by the appearance of a burning smell, strong heating of the tool during operation, the appearance of large sparking in the area of ​​the rotor rotor collector, and poor operation of the reverse switch.

The condition of carbon brushes, the reliability of attachment of the brush holders and their proper installation affect the operation of the puncher.

The smell of burning appears during a short circuit of the stator or rotor windings.

A drop in the power of the perforator with an increase in load is characteristic when the rotor windings break or when the carbon brushes are short.

The perforator is most often heated by a short inter-turn short circuit in the stator or rotor.

Large sparking in the area of ​​the collector is caused by interturn closure of the rotor or burnout of the collector lamellas.

The reverse switch is malfunctioning due to the burning of its contacts.

But the main reason for all breakdowns is the untimely performance of technical routine maintenance and the replacement of carbon brushes.

Carbon brushes require replacement after 70 hours of operation or when wearing up to 8 mm in length.

General view and dimensions of the carbon brushes of the Bosch rotary hammer

We gave the main reasons for the failure of Bosch rotary hammers.
Perhaps we did not describe all the breakdowns of Bosch rotary hammers.

If you know other malfunctions at the Bosch 2-20, 2-24, 2-26 rotary hammers, share with us.

Video replacement of the raster sleeve in the cartridge Bosch 2-26

Video of replacing the anchor in a Bosch 2-26 hammer drill