BASICS of squeezes and notice if the hose seems very soft or squishy to the feel. It’s possible the barrier wall inside the hose has deteriorated due to an unknown substance like oil or another chemical that has broken down the barrier. That could be a rupture waiting to happen, especially under a high pressure high heat condition. Other external leak points can be at the water pump weep hole, heater core inlet and outlet hoses as well as the core itself. Other potential leak areas include intake manifold gaskets, cylinder head gaskets, thermostat gaskets and cylinder head or block freeze plug areas. The radiator can develop leaks at the core and especially at the seams of the tank. Newer vehicles, as you know, have plastic tanks that are attached to an aluminum core. That particular area is prone to start leaking.
The methods you use to check for leaks are the same today as you performed in the past. Systems under pressure always tend to show a leak a lot faster than one that’s not under pressure. That’s not to say a system can leak without pressure as in some conditions a leak will show up under an ambient temperature state.
Belts and pulleys
COURTSEY OF SOUTHEAST MOBILE TECH
Figure 2: Rubbed through lower radiator hose.
So what makes a coolant system operate besides having the correct coolant and the right amount of it? It’s the mechanical moving parts that place the system in motion. Those parts consist of a water pump, serpentine belt tensioner, an idler pulley or two, a power steering pump, an air conditioning compressor, and the alternator (see Figure 3 on the next page). All of those things are tied together with a serpentine belt or a combination of serpentine and/or V belts. When checking the mechanical aspect of the cooling system, every component has to be operating correctly. The part that is the most crucial is the belt. Depending on the vehicle, a combination of multiple belts could be used. If they break then everything stops. The belt is also the component that is the weakest. If a component starts to fail, the belt will tend to slip on the pulley thus creating an excessive amount of heat. Over time the belt will become worn or glazed and it will stop gripping the pulley. You can tell that a belt is glazed by not only looking at the belt for a shiny appearance, but it feels a little more brittle and not quite as flexible as it should be. Look for any cracks that tend to develop on the wearable part of the belt as those could be potential failure points. Belts also tend to fail due to different chemicals like oil and coolant leaking on them as well as a sharp object rubbing on them. October 2 019
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