Palm couplings

Yellow and red palm couplings play a crucial role in the connection of brake and air supply systems on trucks and trailers. The yellow palm coupling ensures a continuous supply of compressed air to the trailer brakes, while the red palm coupling controls the brakes and provides a safety function that prevents the trailer from rolling away. The colour coding of these palm couplings helps to avoid confusion and increase safety on the road. 

“When fitting, the yellow palm coupling must always be fitted first, as fitting the red palm coupling alone could cause the brake to come loose, for example, as air is constantly being pumped,” explains Parts Specialist Kevin. DT Spare Parts offers the black version for older vehicles with single-circuit brakes. Should a failure occur here, for example if the cable breaks, it must be replaced immediately, as otherwise the entire train will no longer be braked, warns the workshop professional.

The range also includes various designs. Kevin will be showing two palm couplings, one with an M22 thread and one with an M16 thread. To avoid problems, it is important to observe the vehicle-specific requirements and the cable cross-sections, advises the Parts Specialist. On the front of the palm couplings, you can also recognise that one is equipped with a valve and one without. “The variant with a valve is mainly installed on the vehicle so that no air flows out, for example when the brakes are applied,” explains Kevin. “Another variant is the quick-release coupling,” says the professional. The advantages are obvious. “A quick-release coupling is more precise, can be installed faster and is even more resistant to mix-ups,” says the Parts Specialist.

In addition to numerous palm couplings, the DT Spare Parts range also impresses with matching repair kits and add-on components. In this context, Kevin presents repair kits for the palm couplings themselves. Among other things, these can be used to replace the rubber and the cover, which in turn prevents contamination and water from entering the lines. Workshop professionals will also find air coil hoses in various sizes in the programme, also in yellow, red and black versions. The latter is for universal use. Reinforcement handles are also available for assembly and disassembly. “We also have a wide range of brake hoses in sizes M4 to M18,” explains Kevin. All items can be found in the Diesel Technic Partner Portal: partnerportal.dieseltechnic.com. The high quality and constant optimisation of the products is ensured by the Diesel Technic Quality System (DTQS), which also guarantees a consistently high warranty.

If you have any technical questions about Diesel Technic products and services, the Parts Specialists will be happy to answer them via their HelpDesk and offer the appropriate support: helpdesk.parts-specialists.com.

More information about the Parts Specialists is available on the website: www.parts-specialists.com.