UNION-FLARED 7K1456 - Caterpillar

3176B (9CK),
3406C (8PN),
3406E (5EK),
C-10 (2PN),
C-12 (1YN) Truck EnginesAn 124-5572 Air Compressor Pressure Relief Valve has been installed on many of the above engines. The pressure relief valve is mounted in the outlet port of the air compressor head. The function of the relief valve is to bypass air when there is a malfunction in the air system and to release air pressure at 1722.5 kpa (250 psi). It is, therefore, very important that all personnel are clear of the valve when it releases compressed air. All personnel should also stand clear of the general vicinity of the air compressor when the hood is raised.
In addition, when air is being released the brakes may not contain sufficient air for normal braking operations. It is, therefore, important not to operate the truck until the reason for the air bypass is identified and has been corrected.
(1). If the air compressor pressure relief valve mounted in the air compressor cylinder head is bypassing compressed air, there is a malfunction in the air system, possibly ice blockage. Under these conditions, your truck may have insufficient air for normal brake operation. (2). Do not operate the truck until the reason for the air bypass is identified and corrected. Refer to the information provided in the O&MM. (3). Failure to heed this warning could lead to property damage, personal injury, or death to the truck driver or bystanders.