Test Equipment

Voltmeter, Ammeter and Ohmmeter

A good voltmeter is required for testing ignition and other electrical systems. Voltmeters are avail-

Some manufacturers combine the 3 instruments into one unit called a multimeter or VOM. See Figure 24.

Compression Gauge

An engine with low compression cannot be properly tuned and will not develop full power. A compression gauge measures the amount of pressure present in the engine's combustion chambers during the compression stroke. This indicates general engine condition.

The easiest type to use has screw-in adaptors that fit into the spark plug holes (Figure 25). Press-in rubber-tipped types (Figure 26) are also available.

Dial Indicator

Dial indicators (Figure 27) are precision tools used to check dimension variations on machined parts such as transmission shafts and axles and to check crankshaft and axle shaft end play. Dial indicators are available with various dial types for different measuring requirements.

Strobe Timing Light

This instrument is necessary for checking ignition timing. By flashing a light at the precise instant the spark plug fires, the position of the timing mark can be seen. The flashing light makes a moving mark appear to stand still opposite a stationary mark.

Suitable lights range from inexpensive neon bulb types to powerful xenon strobe lights. See Figure 28. Alight with an inductive pickup is recommended to eliminate any possible damage to ignition wiring.

Portable Tachometer

A portable tachometer is necessary for tuning. See Figure 29. Ignition timing and carburetor adjustments must be performed at the specified idle speed. The best instrument for this purpose is one with a low range of 0-1,000 or 0-2,000 rpm and a high range of 0-4,000 rpm. Extended range (0-6,000 or 0-8,000 rpm) instruments lack accuracy at lower speeds. The instrument should be capable of detecting changes of 25 rpm on the low range.

Expendable Supplies

Certain expendable supplies are also required. These include grease, oil, gasket cement, shop rags and cleaning solvent. Ask your dealer for the special locking compounds, silicone lubricants and lube products which make vehicle maintenance simpler and easier. Cleaning solvent is available at some service stations.

MECHANIC'S TIPS Removing Frozen Nuts and Screws

When a fastener rusts and cannot be removed, several methods may be used to loosen it. First, apply penetrating oil such as Liquid Wrench or WD-40 (available at hardware or auto supply stores). Apply it liberally and let it penetrate for 10-15 minutes. Rap the fastener several times with a small hammer; do not hit it hard enough to cause damage. Reapply the penetrating oil if necessary.

For frozen screws, apply penetrating oil as described, then insert a screwdriver in the slot and rap the top of the screwdriver with a hammer. This loosens the rust so the screw can be removed in the normal way. If the screw head is too chewed up to use this method, grip the head with Vise-grips pliers and twist the screw out.

Avoid applying heat unless specifically instructed as it may melt, warp or remove the temper from parts.

Remedying Stripped Threads

Occasionally, threads are stripped through carelessness or impact damage. Often the threads can be cleaned up by running a tap (for internal threads on nuts) or die (for external threads on bolts) through the threads. See Figure 30. To clean or repair spark plug threads, a spark plug tap can be used (Figure 31).

Removing Broken Screws or Bolts

When the head breaks off a screw or bolt, several methods are available for removing the remaining portion.

If a large portion of the remainder projects out, try gripping it with Vise-grips. If the projecting portion

is too small, file it to fit a wrench or cut a slot in it to fit a screwdriver. See Figure 32.

If the head breaks off flush, use a screw extractor. To do this, centerpunch the exact center of the re maining portion of the screw or bolt. Drill a small hole in the screw and tap the extractor into the hole. Back the screw out with a wrench on the extractor. See Figure 33.

Tables 1-5 are on the following pages.


Simple Car Care Tips and Advice

Simple Car Care Tips and Advice

Put an End to All Your Car Troubles. Does Your Car Break Down Often? Are You Spending More On Fuel Than You Thought You Would? Is Maintaining Your Car Eating Into Your Budget? Make Your Car Last Longer with Some Simple Do It Yourself Tips.

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