2. Damage to the inner rubber layer
(1) The adhesive layer in the hose is hard and cracked. The hoses are flexible and malleable due to the plasticizers added to the rubber products. The hose operates at high temperatures and pressures, and overheating of the hose can cause the plasticizer to overflow. In addition, when the superheated fluid passes through the cylinders, valves or other components of the system, a large pressure drop will decompose the fluid, causing the glue layer inside the hose to oxidize and harden. In this case, the hydraulic system should first check the operating temperature is normal, valve throttle, pump suction channel is open, etc. Replace the hose after eliminating any factors that may cause the oil temperature to be too high and the fluid to decompose.
(2) The adhesive layer in the hose is seriously deteriorated and obviously swelled. The reason is that hydraulic oil is used for too long or oxidized dirt exists in the hydraulic system, the hose is chemically altered, and broken rubber sheets are found in the return port. If this occurs, the hydraulic oil's physicalization indicators should be checked first and the compatibility of the system fluid in the hose glue material and the operating temperature conform to the standard.