A brake cylinder maintaining system that combines a brake cylinder maintaining check valve and a quick service limiting valve into a single unit to have lower hysteresis, and thus more precise BCM regulation pressure and a smaller pressure offset. The check valve and quick service valve are coupled to provide a single system having multiple valve seats for selective communication between quick service pressure and brake cylinder pressure on one hand, and between a brake cylinder maintaining pressure and brake cylinder pressure on the other hand.

A hot wheel protection valve arrangement including a hot wheel protection valve, the hot wheel protection valve including a body defining a passageway, a piston slidably positioned within the passageway, a bushing positioned on the piston and within the passageway, a first diaphragm provided on a first end of the piston, the first diaphragm defining a first chamber in the passageway, a second diaphragm provided on a second end of the piston, the second diaphragm defining a second chamber in the passageway, a third chamber being defined between the first diaphragm and the second diaphragm, and an exhaust port defined in the body and in fluid communication with the third chamber, a brake cylinder line that establishes fluid communication between a brake cylinder, the first chamber, and the third chamber; and an emergency reservoir line that establishes fluid communication between an emergency reservoir and the second chamber.

A hot wheel protection valve arrangement including a hot wheel protection valve, the hot wheel protection valve including a body defining a passageway, a piston slidably positioned within the passageway, a bushing positioned on the piston and within the passageway, a first diaphragm provided on a first end of the piston, the first diaphragm defining a first chamber in the passageway, a second diaphragm provided on a second end of the piston, the second diaphragm defining a second chamber in the passageway, a third chamber being defined between the first diaphragm and the second diaphragm, and an exhaust port defined in the body and in fluid communication with the third chamber, a brake cylinder line that establishes fluid communication between a brake cylinder, the first chamber, and the third chamber; and an emergency reservoir line that establishes fluid communication between an emergency reservoir and the second chamber.