WD Catalog 2018

Chapter 7

– Inspection & Maintenance

7-4

Go to Chapter Start

Table of Contents

Index

C. Drive Belt

– The drive belt should be tight and in good condition.

Use a belt tension gauge to check tension (120 pounds maximum).

With experience, you can feel belt tension by twisting the belt. Try

feeling belt tension after using the gauge, when you know the

tension is correct. Replace belts if they are frayed or look worn.

If the clutch pulley/belt alignment is obviously off, you need to

loosen the compressor or mounting bracket, or both—and use the

alignment bar to line up the clutch pulley with the drive pulley.

Tighten compressor mounting bolts first, then the bolts holding the

bracket. The mounting bracket should have slots or other means of

adjustment to allow you to adjust the tension of the drive belt. When

you use a pry bar to apply tension, be sure you do not pry against the

compressor. Pry against the mounting bracket.

3. Check Hoses and Fittings

Check all hoses and fittings. Look for places where hoses flex when the

cab is tilted. Any places the hoses or fittings are fastened, clamped,

connected, bent or secured are potential wear points. This also applies to

places where hoses are not clamped or supported but should be (often

near the condenser). All of these spots are potential leak or damage

points. Tighten, re-fasten, add, or replace as indicated by your inspection.

4. Check for Refrigerant Leaks

System refrigerant leaks can be anywhere but there are obvious places.

You can spot some by looking for signs of refrigerant oil forced out with

refrigerant leakage. One location leaks frequently occur is the compressor

shaft seal. The shaft and seal are hidden behind the clutch assembly, but

centrifugal force will throw the oil off the shaft and against the engine,

bracket or whatever is close. Check these points when you examine the

compressor clutch and mounting bracket. A solution of soap and water

applied around potential leak points works well for detecting leaks. A leak

in the evaporator may be indicated if you feel around the condensate

drain hole and find oil present.

Note:

You can add inexpensive dry nitrogen gas to the sys-

tem instead of R-12 if system pressures are low. Dis-

pense the gas at no more than 200-250 PSI as this is

sufficient pressure to cause or indicate a leak point in

the AC system. AC service procedures for complete

system recovering of refrigerant, evacuating, and re-

charging are covered and illustrated in

Chapter 9.

Note:

A leaking heater core could also result in coolant at

the condensate drain.