Common failure and troubleshooting

After the driver releases the brake pedal, trailer braking process of disarmament not only lag behind the car and slowly (after you release the brake pedal motor vehicles is required for a while feel normal), and braking at the trailer lift exhaust sound lighter and longer. This symptom may occur not only in trailers used after a period of time, and early in the new trailer used may also occur.

the cause
Trailer brake distribution valves for exhaust valves (formed by the exhaust valve and exhaust valve seat) the exhaust gap (opens the exhaust valve and exhaust valve clearance exhaust valve seat) had little or no gap.
Note: If the inspection discloses that only one trailer wheel brake lifting very slowly, whereas other brake release is normal, the fault does not belong to the above fault. This fault can be caused by the wheel the wheel brake clearance or corrosion of the brake camshaft.

Troubleshooting
Decomposed trailer brake distribution valves and clean all parts and should focus on examining the exhaust valve seats for visible deformation and damage. If so, the exhaust valve seat should be replaced if normal exhaust valve seat, the exhaust valve and core rod between a thick 0.2-0.5M flat gasket, exhaust to increase the exhaust valve clearance.
When refitted trailer brake distribution valves, you should check whether the gasket thickness increased by right. Inspection method is: after the trailer brake distribution valves are assembled together, the 4 fastening nuts (diagram does not draw) gently twist in the end (below the trailer brake distribution valves cover and the valve between the left 0.5mm gap), and then I'm assigned to trailer brake valve Central connects with the trailer brake valve blowing gas. As the air blows out, then the gasket thickness increase is too large and should instead use the thickness of the gaskets. If you can't blow the gas out, then add the shim thickness initial inspection with the right, and then tighten the 4 fastening nut (no clearance between the lower cover and the valve), then use the same method to check. At this point, as with blows blowing out air, the extra thickness of the gaskets fit; as with a big blow or not to blow out or just able to blow out some air and exhaust the exhaust valve clearance is too small, also for thicker gaskets.