The Function of the quick release valve in the secondary brake circuit is to:
Speed up the release of front brakes
A quick release valve is often used in parking/emerg brake circuits to provide quick:
Application of the spring brakes
When the compressor is in it’s unloaded cycle?
The inlet valves are held open
In a relay emergency valve, the emergency piston moves down at ______psi and _____the inlet valve and______the exhaust valve
40-45psi
Close inlet valve
Open the exhaust valve
What is different between a charging and non charging relay emergency valve
One way check valve
This component is used to prevent compounding in the spring brake chambers
Double check valve
Or
Anti compounding valve
CMVSS 121 states that the trailer supply valve must automatically apply at ?
50 psi
What is a normal braking application pressure?
1-30psi
If a body loaded truck comes to your shop with excessively worn front brakes, and rear brakes with very little wear what could be the cause?
Leaking treadle valve
Cracking pressure of rear brakes relay valve may be to high
A properly adjusted foundation brake has to meet these 2 requirements
Pushrod travel must be less than stroke length
90-95 degree angle
When preparing to install a spring brake chamber what should be done
Cage the the spring brake chamber
Place the brake chamber into the appropriate brake assembly bracket. Tighten the holding nuts too?
100-140 ft lbs
Red dash button should pop out at what psi after disconnecting glad hands
40-60 psi or higher
Yellow dash button will pop out at what ____ psi
45-20 psi
When visually inspecting the compressor mounting security look for
Cracked or damaged mounting brackets
Loose or missing fasteners
A properly adjusted compressor drive belt will have a maximum deflection of
1/2 to 3/4 inch (12.70-19.05 mm)
Dented or kinked air lines in the parking/emergency brake circuit could cause the spring brakes to:
Be sluggish when applied and released
Before you attempt to mechanically cage spring brakes you should
Inspect spring brake chamber for damage
Alberta CVIP states that a vehicle will fail inspection if the radial clearance between the camshaft and bushing is
0.085 inch (2.16 mm)
Camshaft axial play should not exceed
0.030 inch (0.76 mm)
Removing material from the inside diameter of a brake drum results in
Reduced strength and reduced ability to dissipate heat
Stroke should be adjusted to:
As short as possible without brakes dragging
Alberta CVIP states that an air brake equipped vehicle will be put out of service if the brake lining are worn below
5/16 inch (8mm)
Alberta CVIP states that a vehicle will fail inspection if radial clearance is between camshaft and bushing is
.085 (2.1mm)
