Troubleshooting Guide
This document is released under the terms of the
Creative Commons License
unless otherwise noted.
Thanks to Abingdon Classics for writing this article.
Last modified 2006-04-02.
First published in "Abingdon Classics" November, 1981
From the NAMGBR
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Brakes |
Engine |
Steering |
Fuel |
Electrical |
Clutch |
Cooling
Brakes Problem Solvers |
 |
| PROBLEM |
CAUSE |
CURE |
| Excessive brake pedal travel |
- Brakes need adjusting or replacement.
- Air in system.
- Faulty master cylinder.
- Leaking or contaminated fluid.
|
- Adjust or renew brake shoes.
- Bleed hydraulic system.
- Fit new master cylinder.
- Bleed hydraulic system.
|
| Brake fade |
- Incorrect pad or lining material.
- Old or contaminated fluid.
- Excessive use of brakes or car overloaded.
|
- Fit new pads or shoes.
- Renew brake fluid.
- Check vehicle load.
|
| Spongy brake pedal |
- Air in hydraulic system.
- Shoes badly lined or distored.
- Faulty hydraulic cylinder.
|
- Bleed system.
- Fit new pads or shoes.
- Check hydraulic circuit.
|
| Brake pedal too hard |
- Seized wheel cylinder or caliper piston
- Glazed fiction material
|
- Replace seized component.
- Fit new shoes/pads.
|
| Brake pedal requires pumping or loss of pedal |
- Brakes wrongly adjusted
- Air in hydraulic system
- Fluid leak from component or brake pipe
- Loss of fluid from master cylinder
|
- Adjust brakes.
- Bleed system.
- Check hydraulic circuit and replace parts as necessary.
- Check hydraulic circuit and replace parts as necessary.
|
| Brakes grab when applied |
- Contaminated friction material
- Wrong linings fitted
- Scored drums or discs
|
- Replace (don't clean) pads or shoes.
- Replace (don't clean) pads or shoes.
- Fit new drum or disc.
|
| Brake squeal |
- Worn retaining pins (disc)
- Faulty damping shims or shoe retaining clips
- Dust in drum
- Loose backplate or caliper
|
- Fit new pins.
- Fit new shims or clips.
- Remove dust from drums and shoe.
- Tighten caliper or backplate.
|
| Brake shudder |
- No clearance at master cylinder operating rod
- Shoe tension springs either broken or week
- Wheel cylinder or caliper piston seizing
- Faulty self-adjusting mechanism
- Seized handbrake mechanism
|
- Adjust rod if possible.
- Replace tension springs
- Fit new caliper or cylinder.
- Check mechanism.
- Check handbrake operation.
|
| Brake pull to one side only |
- Contaminated friction material on one side (grease, oil or brake fluid>
- Loose backplate
- Seized cylinder
- Faulty suspension or steering
|
- Replace shoes/pads all around.
- Tighten backplate.
- Replace seized cylinder.
- Check suspension and steering.
|
| Handbrake ineffective |
- Worn rear shoes or pads
- Brakes require adjusting
- Faulty handbrake linkage
- Cable or rod requires adjustment
|
- Fit new pads/shoes.
- Adjust brakes
- Check linkage and operating mechanism.
- Adjust cable or rod.
|
| Servo (where fitted) late in operation |
- blocked filter
- Bad vacuum sealing or restricted air inlet
|
- Clean or replace filter.
- Tighted vacuum hose connections and check hoses
|
| Loss of servo action when braking heavily |
- Air leak in servo-vacuum low
|
- Either overhaul servo or replace
|
| Loss of fluid (servo only) |
- Seal failure
- Scored servo bores
- Damaged or corroded fluid pipes
| - Replace or overhaul servo.
- Replace or overhaul servo.
- Inspect and fit new pipes.
|
Index | Engine | Steering | Fuel | Electrical | Clutch | Cooling
Engine Problem Solvers |
 |
| PROBLEM |
CAUSE |
CURE |
| Lack of compression |
- Faulty valve seat, excessive wear in stem or guide.
- Faulty head gasket.
- Worn pistons, rings and bores.
|
- Recut seat and valve, fit new guide and valve.
- Fit new gasket or reface head.
- Either fit new rings, or if badly worn, fit new pistions and rings, and have block rebored.
|
| Piston slap |
- As #3 above.
|
- As #3 above.
|
Smoke from exhaust Lack of power |
- As above.
- Blocked crankcase breather.
|
- As above.
- Check breathing apparatus.
|
| Noisy tappet (with correct clearance) |
- Wear in rocker pad face and/or rocker sleeve and shaft (OHV).
- Worn cam follower (OHC).
|
- Reface pad surface, replace rockers or shaft (OHV).
- Fit new followers (OHC).
|
Big-end knock |
- Wear between big-end shell and crankcase. Wrong torque on bolts.
| - Depending on wear, fit new shells, regrind crankshaft and check torqu
|
Mains rumble |
- Wear between main bearing shells and crankshaft.
|
- As Above
|
| Cam follower tap |
- Camshaft worn or follower dished.
|
- Examine and replace followers or camshaft. Or Both
|
| Knocking when clutch depressed. Movement at crank pulley |
- Excessive crankshaft end-float. Wear between crank and thrust washer.
| - Fit new thrust washers and recheck clearance.
|
| Clattering from fron of engine |
- Excessive or slack timing chain, worn chain tensioner.
|
- Fit new chain and tensioner. Adjust chain were necessary.
|
| Small-end or gudgion pin knock |
- Excessive wear between gudgeon pin and con-rod.
|
- Fit new bush or con-rod.
|
| Lack of oil pressure |
- Excessive wear in crankshaft journals.
- Faulty oil pump.
- Blocked oil pick-up strainer.
- Faulty pressure-relief valve.
- Blocked oil filter.
- Lack of oil
|
- Overhaul engine.
- Fit new pump.
- Clean pick-up.
- Fit new relief valve.
- Fit new filter.
- Install fresh oil.
|
| Oil leaks |
- Sump gaskets or packings.
- Front and rear crankshaft oil seal.
- rocker or camshaft gasket.
- Oil filter.
|
- Fit new gaskets.
- Fit new seals.
- Fit new gasket.
- Check filter seal.
|
| Lack of power (engine in good condition) |
- Faulty ignition timing. Faulty sparking plugs, points or condenser. Wrong valve clearance.
|
- Tune engine.
|
Brakes | Index | Steering | Fuel | Electrical | Clutch | Cooling
Steering Problem Solvers |
 |
| PROBLEM |
CAUSE |
CURE |
| Steering feels stiff |
- Low tire presures
- Incorrect wheel alignment
- Stiff track rod ends
- Steering box/rack needs adjustment
|
- Correct tire pressures.
- Correct wheel alignment.
- Check and replace if necessary.
- Adjust if necessary.
|
| Steering wheel shake |
- Wheels and tires need balancing
- Tire pressures incorrect
- Incorrect wheel aligment
- Wheel hub nut loose
- Wheel bearings damaged
- Front suspension distored
- Steering box/rack needs adjustment
- Shock absorbers faulty
|
- Correct.
- Correct alignment.
- Adjust wheel bearings.
- replace wheel bearings.
- Check, repair or replace.
- Adjust as necessary.
|
| Steering pulls to one side |
- Uneven tire pressure
- Wheel alignment incorrect
- Wheel bearings worn or damaged
- Brakes imporperly adjusted
- Shock absorbers faulty
- Suspension distorted
- Steering box/rack worn
|
- Correct.
- Correct.
- Replace and adjust.
- Adjust brakes.
- Check and rectify.
- Check and rectifly.
- Adjust and replace.
|
| Wheel tramp |
- Over-inflated tires
- Unbalanced tire and wheel
- Defective shock absorber
- Defective tire
|
- Correct pressure.
- Check and balance if necessary.
- Check and rectify.
- Repair or replace.
|
| Abnormal tire wear |
- Incorrect tire pressure
- Incorrect wheel alignment
- Excessive wheel bearing play
- Improper driving
|
- Check pressures.
- Check wheel alignment.
- Adjust wheel bearings.
- Avoid sharp turning at high speeds, rapid starting and braking, etc.
|
| Tire noises |
- Improper tire inflation
- Incorrect wheel alignment
|
- Correct tire pressures.
- Correct wheel alignment.
|
Brakes | Engine | Index | Fuel | Electrical | Clutch | Cooling
 |
Fuel Problem Solvers |
| PROBLEM |
CAUSE |
CURE |
| Flooding |
- Improper seating or damaged float needle valve or seat
- Incorrect float level
- Fuel pump has excessive pressure
|
- Check and replace parts as necessary.
- Adjust float level.
- Check fuel pump.
|
| Excessive fuel consumption |
- Engine out of tune
- Float level too high
- Loose plug or jet
- Defective gasket
- Fuel leaks at pipes or connections
- Choke valve operates improperly
- Obstructed air bleed
|
- Tune engine.
- Adjust float leverl.
- Tighten plug or jet.
- Replace gaskets.
- Trace leak and rectify.
- Check choke valve.
- Check and clear.
|
| Stalling |
- Main jet obstructed
- Incorrect throttle opening
- Slow-running adjustment incorrect
- Slow-running fuel jet blocked
- Incorrect float level
|
- Clean main jet.
- Adjust throttle.
- Adjust slow-running.
- Clean jet.
- Adjust float leverl.
|
| Poor acceleration |
- Defective accelerator pump (if fitted)
- float level too low
- Incorrect throttle opening
- Defective accelerator linkage
- blocked pump jet
|
- Overhaul pump.
- Adjust float lever.
- Adjust throttle.
- Adjust accelerator linkage.
- Clean pumpjet.
|
| Spitting |
- Lean mixture
- Dirty Carburetor
- Clogged fuel pipes
- Manifold draws secondary air
|
- Clean and adjust carburetor.
- Clean carburetor.
- Clean and replace pipes.
- Tighten or replace gasket.
|
| Insufficient fuel supply |
- Clogged carburtor
- Clogged fuel pipe
- Dirty fuel
- Air in fuel system
- Defective fuel pump
- Clogged fuel filter
|
- Dismantle and clean carburetor.
- Clean fuel pipe.
- Clean fuel tank.
- Check connections and tighten.
- repair or replace fuel pump.
- Clean or replace filter.
|
| Loss of fuel delivery |
- Pump faulty (electric)
- Slotted body screws loose
- Diaphragm cracked
- Loose fuel pipe connections
- Defective valves
- Cracked fuel pipes
| - replace pump.
- Tighten body screws.
- Overhaul fuel pump.
- Tighten fuel pipe connections.
- Replace valves.
- Replace fuel pipes.
|
| Noisy pump |
- Loose pump mounting
- worn or defective rocker arm (if manual)
- Broken rocker arm spring (if manual)
|
- Tighten mounting bolts.
- Replace rocker arm.
- Replace spring.
|
Brakes | Engine | Steering | Index | Electrical | Clutch | Cooling
Electrical Problem Solvers |
 |
| PROBLEM |
CAUSE |
CURE |
| STARTER |
Starter doesn't turn (lights dim) |
- Battery flat or worn
- Bad connection in battery circuit
|
- Charge or fit new battery.
- Check all feed and earth connections.
|
starter doesn't turn (lights stay bright) |
- Faulty ignition switch
- Broken starter circuit
|
- Check switch.
- Check starter circuit.
|
| Solenoid switch chatters |
- Flat battery
| - Charge or replace battery
|
| Starter just spins | - Bendix gear sticking
|
- Remove starter and clean or replace Bendix gear.
|
| CHARGING CIRCUIT |
| Low or no charge rate |
- Broken or slipping drive belt
- Poor connections on or faulty alternator.
|
- Fit new belt.
- Check and replace alternator.
|
| LIGHTING CIRCUIT |
| No lights (or very dim) |
- Flat or faulty battery, bad battery connections
|
- Check battery and connections.
|
| side and rear lights inoperative although stoplights and flashers work | - Fuse blown
|
- Fit correct value fuse
|
| One lamp fails |
- Blown bulb
- Poor bulb contact
- Bad earth connection
- Broken feed
|
- Fit new bulb.
- Check connections.
- Check connection.
- Check feed.
|
| Flasher wrning bulb stays on or flashers twice as fast |
- Faulty bulb or connection on front or rear of offending side
| - Fit new bulb, make good connection.
|
| Lights dim when idling or at low speed |
- Loose drive belt
- Flat battery
- Faulty charging circuit
|
- Tighten belt.
- Check charge output and battery.
- Check charge output and battery.
|
| One dim light |
- Blackened bulb
- Bad earth
- Tarnished reflector
|
- fit new bulb or sealed-beam.
- Check earth connections.
- Fit new bulb or sealed-beam.
|
| WINDSCREEN WIPERS |
| Wipers do not work |
- Blown fuse
- Poor connection
- Faulty switch
- Faulty motor
|
- Fit fuse.
- Check connections
- Check switch.
- remove and examine motor.
|
| Motor operates slowly |
- Excessive resistance in circuit or wiper drive
- worn brushes
|
- Check wiper circuit.
- Remove motor and check brushes.
|
Brakes |
Engine |
Steering |
Fuel |
Index |
Clutch |
Cooling
 |
Clutch Problem Solvers |
| PROBLEM |
CAUSE |
CURE |
| Clutch slips |
- Clutch facing worn
- Clutch facing contaminated
- Warped clutch cover or pressure plate
- Incorrect adjustment (if adjustable)
|
- replace clutch assembly.
- replace Clutch assembly.
- Replace clutch assembly.
|
| Clutch drags |
- faulty clutch hydraulics (if hydraulic)
- Faulty clutch adjustment (if adjustable)
- Clutch disc warped
- Clutch hub spines worn or rusty
- diaphragm worn or mal-adjusted
| - Overhaul or replace clutch hydraulics.
- Adjust clutch.
- replace clutch disc.
- replace or lubricate clutch.
- Replace pressure plate
|
| Clutch chatter |
- Faulty pressure plate
- Faulty clutch discLoose or worn engine mounting
|
- Replace pressure plate.
- Replace clutch disc.
- Replace mounting.
|
| Clutch noise |
- Insufficient grease on bearing sleeve
- Clutch installed incorrectly
|
- Lubricate
- Check installation.
|
| Clutch noise (pedal down) |
- Faulty release bearing
|
- Replace bearing
|
| Clutch noise (pedal on the way up) | - Damaged or worn pilot bearing
| - Fit new bearing
|
| Clutch grabs |
- Contaminated clutch lining
- Clutch worn or loose rivets
- Clutch splines worn or rusted
- Warped flywheel or pressure plate
- Loose mountings on engine or power unit.
|
- replace clutch.
- replace clutch.
- Clean or replace.
- Repair or replace.
- Tighten or replace.
|
Brakes | Engine | Steering | Fuel | Electrical | Index | Cooling
Cooling Problem Solvers |
 |
| PROBLEM |
CAUSE |
CURE |
| Overheating |
- Inoperative thermostat
- Radiator fin choked with mud, leaves, etc.
- Incorrect ignition and valve timing
- Dirty oil and sludge in engine
- Inoperative water pump
- Loose fan bels
- Restricted radiator
- Inaccurate temperature gauge
- Impurtiy in water
|
- Replace thermostat
- Clean out air passage.
- Tune engine.
- Change engine oil and filter.
- Replace (or check electrical).
- Adjust tension.
- Flush Radiatro.
- Replace temperature gauge.
- Use sofe, clean water.
|
| Loss of coolant |
- Leaking radiator hose(s)
- Damaged radiator
- Leak at heater connection or plug
- damaged cylinder head gasket
- Cracked cylinder block
- Cracked cylinder head
- Loose cylinder head bolts
|
- Replace.
- Repair or replace radiator.
- Repair or replace.
- Replace gasket. Check engine oil and refill as necessary.
- Replace cylinder block. Check engine oil in crankcase for mixing with water.
- Replace cylinder head.
- Tighten cylinder head bolts.
|
| Overcooling | - Inoperative thermostat
- Inaccurate temperature gauge
|
- Replace thermostat.
- Replace temperature gauge.
|
| Poor circulation |
- Restriction in system
- Insufficient coolant
- Inoperative water pump
- Loose fan belt
- Inoperative thermostat
|
- Check hoses for crimping. Clear the system of rust and sludge.
- Replenish.
- Replace water pump.
- Adjust fan belt.
- Replace thermostat
|
| Corrosion |
- Excessive impurity in water
- Infrequent flushing and draining of system
|
- Use soft, clean water.
- Flush thoroughly at least twice a year.
|
From the NAMGBR.
Article by Abingdon Classics
2006-04-02
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