Auto Service World
Feature   February 1, 2011   by Tom Venetis, Editor

Taking on the Belt and Hose

Want to generate some profit? Here are a few handy tips on belt and hose diagnostics that will do just that.

Sometimes, we get too wrapped up in the job we are doing to notice a problem that is staring us right in the face. When you have a vehicle up on the hoist for an oil change or even some brake work, how often do you take the time to check the engine belts? How often do you look at the hoses when you are swapping out an old air filter or checking fluid and oil levels? This is not a criticism. We are all very busy and likely focused on doing the very best for the customer’s vehicle. If you do a bang-up job on that brake work or get a person’s vehicle in and out of the shop quickly during an oil change, with a vacuumed interior thrown in as well, you will likely have that customer come back.
The problem is if after that profitable oil change or brake work that customer’s vehicle experiences a hose or belt failure, your shop will likely get the blame. The customer will ask why, when the car was in the shop’s bay, the problem with that belt or hose was not noticed?
SSGM Magazine has written a number of articles over many years on belt and hose maintenance, so we are going to summarize some key things to look for which can tip-off a technician that there is a potential problem and demands the belt or hose be replaced. It takes only a few minutes and can be made part of any technician’s normal workflow on any job. Those few minutes can result in more profits and happier customers.
Troubleshooting Belt Failure
Serpentine belts are the literal lifeline of the engine. If that belts brakes, it can cause a host of costly problems for a person’s vehicle, including failure of the alternator, water pump, power steering system or the air conditioning. Any of these failures will cause a fuming customer to enter your shop, especially if the failure could have been avoided with a few quick visual inspections of the belt.
Take the time to look for such things as belt abrasion, where the each side of the belt looks shiny or glazed. This is usually caused by the belt coming into contact with some foreign object or improper belt tension or a mismatched pulley bearing size. Chunk-out is another sign the belt needs to be replaced and this caused by age, heat and stress. Cracking is another obvious sign that the belt needs to be replaced and often results from age, high temperatures and stresses placed on the belt as its operates. Sometimes improper installation of the belt or misalignment can cause premature wear leading to belt failure. Improper installation will cause the belt rib to begin separating from the jointed strands which after time will spread and cause the belt to unravel. Misalignment issues will be visible on the belt by the sidewalls of the belt appearing glazed or frayed. A keen ear can even pick-up the noise such a problem produces.
Now, these tips are for traditional Neoprene belts and many technicians have spent a good part of their working lives diagnosing and replacing these belts. But over the last few years, EPDM belts have begun to replace the older belt technologies. The advantage of EPDM is that it last longer and is resistant to noise and cracking. The challenge for a technician is that it is visually harder to detect belt wear and failure as the traditional signs of chunk-out and cracking do not happen. These belts do wear, but over time, steadily losing rubber material.
To make it easier to diagnose belt wear Gates Corporation offers a free belt wear gauge that allows a technician to see how much material has been lost. SSGM Magazine has a video at demonstrating this tool and showing a belt replacement using a Gates Micro-V AT EPDM belt.
Don’t wait for the hose to break
Having a hose break is never a good thing. I once had a cooling hose break and it was not a pretty experience. As with belts, signs of wear can be spotted if the time is taken to look for them.
The most obvious sign of trouble is if there is moisture or dripping from around the clamps or connections on a hose. While this might be cause by a clamp not being on tight enough, a technician should take it as a sign that the hose may be deteriorating. If the clamp is on tight and in good condition, it is likely time to replace the hose before something goes wrong. Electrochemical Degradation (ECD) damage is another problem that can affect a hose. ECD is a bit tricky as it is not obvious by a simple visual inspection. The hose will look fine to the naked eye. The surest way to tell if a hose is experiencing ECD is by feel, noting any voids, crack or weak spots. If there are any, that hose has to be replaced, preferably with a hose that is made to withstand ECD damage.
Just as feel can help diagnose an ECD-compromised hose, a hose that feels soft, spongy or showing telltale swelling can be signs of the hose suffering oil damage. Oil can react chemically with the rubber and cause the structure of the molecular bonds to weaken and separate by layers which is the cause of the swelling.
Along with replacing the hose, take the time to track down the oil leak as well. Hoses can also be damaged by excessive heat or abrasion or even ozone caused by pollution. In any case, checking the hoses anytime the vehicle is in the shop is a sure way to catch problems before they result in something unpleasant happens for the driver; and it is a sure way to increase customer satisfaction and profit.

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