Speedaire 4B242A Instructions D'utilisation Et Manuel De Pièces page 5

Speedaire Operating Instructions and Parts Manual
Models 4B242A and 4B243A
Troubleshooting Chart
Symptom Possible Cause(s)
Low discharge 1. Air leaks
pressure
2. Leaking valves
3. Restricted air intake
4. Slipping belts
5. Blown gaskets
6. Low compression
Overheating 1. Poor ventilation
2. Dirty cooling surfaces
Unit stalls
NOTE: Electric models are equipped with a pressure switch that automatically turns the motor OFF when the tank pres-
sure reaches a preset level. After air is used from the tank and drops to a preset low level, the pressure switch automati-
cally turns the motor back on.
1. Overloaded motor
2. Improper lubrication
3. Low oil level
Excessive belt 1. Pulley out of alignment
wear 2. Belt too loose or too tight
3. Belt slipping
4. Pulley wobbles
Excessive noise 1. Loose motor or compressor
(knocking) pulley
2. Lack of oil in crankcase
3. Worn connecting rod
4. Worn piston pin bushing
5. Worn bearings
6. Piston hitting the valve plate
7. Noisy check valve
Oil in the dis- 1. Worn piston rings
charge air 2. Compressor air intake
restricted
3. Restricted breather
4. Excessive oil in compressor
5. Wrong oil viscosity or type
6. Connecting rod out of
alignment
Corrective Action
1. Listen for escaping air. Apply soap solution to all fittings and connections. Bubbles
will appear at points of leakage. Tighten or replace leaking fittings or connections
2. Remove head and inspect for valve breakage, weak valves, scored valve seats, etc.
Replace defective parts and reassemble
Be sure that the old head gasket is replaced with a
new one each time the head is removed
3. Clean the air filter element
4. Loosen motor clamping bolts and move the motor in a direction away from the
compressor, being sure that the motor pulley is perfectly aligned with the fly-
wheel. Tighten motor clamping bolts. The belt should deflect about 1/2 in. under
5 lbs. of force. Do not "roll" belts over pulleys
5. Replace any gaskets proven faulty on inspection
6. Low pressure can be due to worn rings and cylinder walls. Correction is made by
replacing the rings, cylinders, and pistons as required
1. Relocate the compressor to an area where an ample supply of cool, clean, dry and
well-circulated air is available
2. Clean the cooling surfaces of pump and motor/engine
1. Have certified electrician check the motor and wiring, then proceed with his/her
recommendations. Check motor voltage connection
2. See Compressor Pump Section, under Assembly
3. Check oil level. Fill if necessary
1. Realign motor pulley with compressor pulley
2. Adjust tension (See Belt Drive Section)
3. Adjust tension or replace belt (See Belt Drive Section)
4. Check for worn crankshaft, keyway or pulley bore resulting from running the
compressor or motor with loose pulleys. Check for bent pulleys or bent crankshaft
1. Loose motor or compressor pulleys are a very common cause of compressors
knocking. Tighten pulley clamp bolts and set-screws
2. Check for proper oil level; if low, check for possible damage to bearings. Dirty oil
can cause excessive wear
3. Replace connecting rod
4. Remove piston assemblies from the compressor and inspect for excess wear.
Replace excessively worn piston pin or pistons, as required
5. Replace worn bearings and change oil
6. Remove the compressor head and valve plate and inspect for carbon deposits or
other foreign matter on top of piston. Replace head and valve plate using new
gasket
7. Replace
1. Replace with new rings
2. Clean filter. Check for other restrictions in the intake system
3. Clean and check breather for free operation
4. Drain down to full level
5. Use Model 4ZF21 Rarus ® 427 oil
6. Replace rod
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4B242A and 4B243A
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