Service Bulletin: Fluid Leak Detection
The following service bulletin was issued by Chevrolet in May of 1986 and contains excellent tips for tracking down hard to find fluid leaks which can be applied to all vehicle lines.
Subject: Fluid Leak Detection
Source: Chevrolet Dealer Service Bulletin
Bulletin Number: 86-83
Date: May, 1986
TO: ALL CHEVROLET DEALERS
When customer vehicles are brought in for fluid leaks from the engine, transmission, cooling system, etc., locating the source of the leak can be challenging.
If the leak is a result of a porous casting, a split seal, or a small pin hole in a hose for example, the source of the leak can be located faster and more accurately with the use of a special fluid additive and a "high intensity" ultraviolet (UV) black light.
These special additives (Dyes) can be added to any mineral based fluid such as engine oil, transmission fluid, engine coolant, power steering and rear axle oil. these special dyes do not harm any GM recommended fluids and usually dissipate afer approximately 300 miles of use.
When the dyes are added to the fluid and properly mixed together (done by normal driving) and then exposed to the black light, the fluid glows a bright yellow or bright green. This allows the source of the leak to be pinpointed, leading to reliable leak correction. There are both "low intensity" and "high intensity" black lights available. The "high intensity" light is preferred, as it has a more concentrated light beam.
"High intensity" black lights are available from several sources, including Kent Moore Tool (J-28428-A) and the GM Tool Equipment Program (#041-00001).
Additives (Dyes) are also available from Kent Moore
J-28431 - Suitable for engine oil, transmission oil, P/S fluid, and rear axle oils.
J-29545 - Used in engine coolant only.
The additives are shipped in a box of 24 one-ounce tubes.