At highway speeds, the flow...
At highway speeds, the flow of coolant into the radiator tends to create negative pressure in the engine's water jackets, which makes this hose collapse. Overheating on the interstate and don't know why? Check the lower radiator hose.
- Stuck thermostat (a misconception; thermostats don't stick, they fail to open).
- Clogged water pump due to corrosion and/or debris.
- Clogged radiator or insufficient radiator capacity.
- Blown cylinder head gasket into water jacket.
- Collapsed lower radiator hose (only if overheating happens on the highway).
- Blocked water jackets (freeze plugs, iron particles, and other debris).
- Wrong pulley sizes, causing water pump to run too fast.
- Thermostat has been removed (engine will overheat in traffic only).
- Fan belt slippage.
- Wrong water pump for application, such as reverse rotation from a late-model 5.0.
Low Oil Pressure
- Excessive bearing clearances.
- Oil pump pressure relief valve stuck.
- Oil pump pick-up loose or bad gasket.
- Clogged oil pump pick-up.
- Oil galley plug loose or missing inside the engine.
- Loose lifter bore clearances.
Baffled by overheating problems...
Baffled by overheating problems and think removing your thermostat will solve the problem? Don't kid yourself. The thermostat is there to regulate coolant flow and allow coolant to transfer heat to the atmosphere in your radiator. Remove the thermostat and expect a boil over in traffic.
- Alternator or generator not charging.
- Voltage regulator contacts open or open circuit inside regulator.
- Battery cells shorted out (known as dead cells; one dead cell causes a weak battery that runs down quickly)
- Belt slippage.
- Incorrect pulley size in front dress.
- Poor electrical connections at alternator, generator, or voltage regulator.
- Failed alternator diode(s).
Headlights/Taillights Inoperative or Cycle Off and On
- Defective headlight switch circuit breaker or short circuit.
- Short circuit can be anywhere between headlight switch and exterior lights.
- Heads-up: old headlight switches suffer from bad circuit breakers.
Always use a 7-pound minimum...
Always use a 7-pound minimum radiator cap. And despite what your father told you ages ago, you can use a 16-pound cap on your classic Mustang. The higher your cooling system pressure, the less chance of a boil over.
- Defective turn signal switch.
- Blown fuse or other reason for no power to switch.
- Defective flasher.
- Bulbs burned out at parking or tail lamp.
Taillights/Parking Lights Keep Blowing Fuses
- Short circuit to ground anywhere between dashboard and lights.
- Short at socket.
- Internal short inside bulb.
Electric Clock Inoperative
- Clock rewind contact points pitted or burned.
- Clock main spring broken (cannot rewind).
- Fuse blown.
Taillight shorts aren't always...
Taillight shorts aren't always wiring, but can be caused by the bulbs themselves, which can short out internally.
- Cable adjustment required.
- Rear brake shoes excessively worn.
- Rear brake drums glazed.
- Rear brake shoe struts/springs require inspection.
Brakes Pull To One Side
- Improper adjustment (too tight on one side, drum brakes only).
- Stuck disc brake caliper piston.
- Improper proportioning valve adjustment (rear brakes will tend to come on first).
Pulsing Brake Pedal
- Warped brake drums or rotors.
- Damaged or excessively worn disc brake pads.
This is the instrument voltage...
This is the instrument voltage limiter, which regulates 12 volts down to 5-volts for proper instrument function. When fuel, temp, and oil pressure needles max out or the gauges stop functioning, the voltage limiter is usually the culprit.
- Worn-out clutch pilot bearing.
- Bent transmission input shaft.
- Bad input shaft bearing.
- Clutch disc contamination (oil, grease, debris).
- Clutch linkage binding.
- Clutch fork adjustment.
Clutch Slips
- Worn pressure plate or clutch disc.
- Contaminated clutch disc.
- Clutch adjusted too tight.
- Clutch disc installed backwards.
Manual Transmission Jumps Out Of Gear
- Maladjusted shifter linkage.
- Worn-out clutch pilot bushing.
- Defective detent mechanism (keeps transmission in specific gears)
- Worn synchronizers
Manual Transmission Noise In Forward Gears
- Lubricant may be low.
- Main and/or counter shaft bearings worn or damaged.
- Synchronizers worn or damaged.
The biggest power steering...
The biggest power steering leak culprit is damaged fitting mating surfaces. Even the smallest nick will cause a leak no matter how tight you get it. Check double flares at all line fittings. Even minute irregularities will cause a leak. Remember, your power steering pump makes 1,800 psi of hydraulic pressure.
- Out of balance clutch/flywheel.
- Release bearing adjustment too tight.
- Bent transmission input shaft.
- Worn or damaged clutch pilot bushing.
Automatic Transmission Slips
- Control pressure low due to defective front pump or damaged seals.
- Low fluid level (slips worse in turns).
- Extremely dirty or burned fluid.
- Clogged transmission filter.
- Sticking valve body pistons.
- Worn servo bands, clutches, or clutch piston seals.
- Defective or improperly adjusted vacuum modulator.
Automatic Transmission Slow To Engage (Any Gear)
- Low control pressure.
- Low fluid level.
- Clogged transmission filter.
- Extremely dirty or burned fluid.
- Leaking clutch piston seals and/or servo piston seals (rebuild necessary)
- Faulty torque converter.
Rear Axle Noise In Forward Gear
- Lubrication low.
- Improper viscosity.
- Excessive ring/pinion backlash.
- Pinion bearings worn or damaged.
- Loose fasteners.
- Rear axle bearings worn out.
Rear Axle Noise While Coasting
- Ring and pinion backlash too tight.
- Excessive pinion bearing wear.
Rear Axle Noise In Turns
- Differential side gears excessively worn or damaged.
- Differential side or pinion gears binding.
Steering Feels Tight
- Steering gear backlash too tight.
- Improper steering gear lubricant.
- Excessive caster (alignment).
- Steering linkage damaged.
- Ball joints binding or seized.
Steering Feels Loose
- Steering gear backlash loose.
- Excessive ball joint play.
- Excessive idler/Pitman arm play.
- Excessive tie-rod end play.
- Wheel bearings not adjusted.
- Excessive toe-in.
- Worn control arm bushings.
Intermittent Instrument Operation
- Instrument voltage limiter (voltage regulator) defective if all instruments involved (except ammeter).
- If problem exists with one instrument only, check sending unit.
Speedometer Erratic
- Binding speedometer cable.
- Speedometer head worn out.
- Damaged speedometer drive gear.
Power Steering Leaks
- Check hose integrity.
- Make sure fittings are tight.
- If fittings are tight, check fitting mating surfaces for nicks.
- Inspect control valve for leaks around Pitman arm and ball valve.
Driveline Vibration
- Driveshaft out of balance.
- Driveshaft run out excessive (bent shaft).
- Universal joints worn or defective.
- Excessive slip yoke wear.
- Differential pinion yoke excessively worn or distorted.