Retarder Expertise
Retarder Service, Repair & Overhaul
A retarder is an auxiliary braking system that slows heavy vehicles without using the service brakes, improving safety on descents. Our scope at KMQ Otomotiv is clear: we repair and fully overhaul Voith hydraulic retarders in our own workshop, and on Telma electromagnetic retarders we supply spare parts without offering repair. We hold original spare-part stock for both systems. With uninterrupted retarder expertise since 2010 and branches in İstanbul, Ankara, Samsun, Gaziantep and Sakarya, we serve fleets across Türkiye.
Voith repaired in our own workshop, Telma supplied as parts
On Voith (hydraulic) retarders everything from diagnosis to final testing stays in our own workshop — the labour is not subcontracted. On Telma (electromagnetic) we supply spare parts and give technical support in choosing them; we do not take on workshop labour such as coil rewinding or rotor balancing. We state this upfront so you do not send a vehicle out for nothing.
Retarder repair
On Voith retarders, we begin with accurate diagnosis for performance loss, overheating, noise or oil leaks, then repair at component level — hydraulic pump, rotor, stator, sealing elements and electronic control unit. Whether a repair or a full overhaul is needed is decided by measurement after teardown.
Retarder overhaul
Complete overhaul for worn or damaged Voith retarder units: teardown, cleaning, wear measurement, part renewal, resealing, testing and performance restoration. A remanufactured unit is an economical, fast alternative to a new one.
Retarder spare parts
We stock original and remanufactured Telma and Voith retarder spare parts: coils, rotors, discs, hydraulic pumps, gasket sets and electronic components — shipped same day from stock.
Compatibility with all heavy-vehicle makes and models
We provide technical support for retarder applications across all heavy-vehicle makes and models, including Mercedes, MAN, DAF, Scania, Volvo and Iveco. Our team helps with correct part selection and installation compatibility.
Retarder service in your city
Unit intake, parts delivery and how the unit reaches the workshop differ by city. Pick yours.
Retarder — frequently asked questions
- What is a retarder and what does it do?
- A retarder is an auxiliary braking system that slows a heavy vehicle without using the service brakes. On long descents it reduces brake-lining and drum wear and improves braking safety.
- What is the difference between Telma and Voith retarders?
- Telma works on an electromagnetic principle: the magnetic field produced by the coils brakes the rotor, and the system is dry. Voith works hydraulically: turbulence in the oil flow creates the braking effect, tied into the cooling circuit. KMQ supplies spare parts for both; workshop repair and overhaul cover Voith only.
- When is a retarder overhaul needed?
- Performance loss, overheating, noise, oil leaks or reduced braking force may require an overhaul. Our technical team diagnoses whether a repair or a full overhaul is needed.
- How quickly are retarder spare parts supplied?
- In-stock Telma and Voith retarder parts ship the same day, with fast delivery across Türkiye through our 5-branch network.
Request a quote — keep your fleet on the road.
Send us your requirement; our technical team responds within 24 hours with the right part and solution.