Welcome to QuickTSI’s latest installment of The Technician’s Log, our long-running look at all things shop-related in trucking. In today’s piece, we are going to talk about two big topics in the shop: seals and batteries. While batteries may seem like a more critical component in the immediate moment, seals are just as equally important in the long run. Let’s look at each of these categories individually.
Seals Under Pressure
Any shop technician will tell you that properly installed and maintained seals will prevent downtime. Leaks are bad. They cause serious headaches for technicians. It is important that the proper tools are used when installing the seal. Manually pushing it into place can lead to problems. There are seals on drive axles, crankshafts and cam shafts.
If a seal installation is not completed properly, the metal of the shaft it is installed in could break through, which leads to serious problems. Once the seal has been compromised a small leak could turn big rather quickly. And when you try to recover from a leak, it isn’t a matter of simply adjusting the seal. Often, compromises seals need to be replaced entirely.
In some cases, you may have to remove other vehicle components just to get to the seal. If the timing belt or driveline are in the way, you face lots of downtime. It is so important that seal work is done right the first time. Seal installation kits make the job much easier and go a long way in ensuring you don’t botch the job.
Before embarking on seal work, it is important you clean the area where the new seal will be applied. Contaminants can compromise a seal job from the outset. Depending on how long the old seal was on installed, there could be even more contaminants. When you look for a seal installation kit, check for an insert tool to put the seal in the right position.
Remember, oil damages seals. If you aren’t operating in a clean environment, the simple act of getting a bit of oil on the seal could result in you trashing it. Always handle a seal by its outside perimeter. You never want to grab it on its fragile inner side. When you install the tool, ensure you apply enough pressure to the tool you are using. Loose seals defeat their purpose.
Some drive axle OEMs offer their own on-line reference manuals. The best seal installation kits should include color-coded tools. Instructions should be easy to read, but thorough enough to clearly explain the job.
Working on pinion seals? Make sure you check and possibly replace them whenever you service the universal joint. If you are nervous about this procedure, there are vendors out there who offer kits to assist with this kind of job. Also consider that maintenance recommendations for these seals must be carefully considered. The manufacturer will generally provide that information.
Work on pinion seals require the removal of other critical components, such as the driveline, pinion shaft and yoke. Any time you work on a seal or must take other components apart to get to a seal, you must use the proper tools and take extra care. It will make your life a lot easier in the shop if you get seals installed correctly the first time, every time.
Keeping Battery Testing in Mind
The electrical systems in commercial motor vehicles are incredibly complex. Their sophistication has risen over the years thanks to the many sensors and connections they must now handle. Whether it be for engine operation or truck driver navigation, there are a lot of things going on in the truck that draw on the battery for power. Your vehicle’s electrical systems must have a stable voltage supply.
The most common battery voltage used in North America is the 12-volt battery. The only difference between a passenger vehicle using a 12-volt battery and a large commercial vehicle are the numbers of batteries they use. Heavy duty commercial motor vehicles require multiple batteries strung together in parallel. This setup provides the cranking energy necessary to start the vehicle and handle the larger, more powerful engine.
You can generally put commercial motor vehicles into two categories: heavy duty automotive and heavy-duty truck. An automotive heavy duty would be something akin to a Ford F350 to F550 chassis. These vehicles use a Group 65 battery for operation. Tow trucks and ambulances also fall under this category.
The entirety of the heavy-duty automotive truck market generally uses the Group 31 model battery. The size and application of the vehicle will dictate how many batteries are required in its operation. Small or medium-duty trucks typically use two batteries. Dump trucks, refuse trucks, and other large-type models will generally rely on three to four batteries.
Heavy-duty commercial motor vehicle batteries are expected to perform well in harsh conditions. They should not only start high compression diesel engines, but they need to provide plenty of power for other truck components that need to draw from it. Urban delivery vehicles sometimes have no-idle requirements. Batteries are required for this. Sleeper cab trucks with lots of internal components need to draw upon copious amounts of power as well.
Looking at Battery Type and Maintenance
Trucks used in certain inner-city applications may need higher amperage alternators for starting and stopping loads. Plus, as truck drivers request more entertainment and support systems, more and more power is required. That’s why it is important that you know what type of battery you need.
Before you can address battery issues, you have got to know what kind of battery you are working with. You should easily be able to identify the batter, especially if you have worked on it in previous applications, or perhaps installed it. Commercial motor vehicles use three types of lead acid batteries.
- Flooded electrolyte batteries
- AGM batteries
- Thin plate pure lead AGM batteries
Flooded lead batteries can generally be counted upon to be relatively maintenance-free. AGM batteries, on the other hand, have a glass mat separator made of fiberglass between each plate. These batteries are spill-proof and do not require topping up during their lifetimes. Some battery companies make batteries with thinner plates, which allows them to have a decreased surface area. This allows more power to be generated out of ever-smaller batteries.
Fleets need to take proper care that batteries do not become too deeply discharged. If the battery drops under 10 volts could cause problems and seep the overall lifetime value out of the battery. Trying to crank vehicles with weak batteries causes high amperages and low voltages. You could be facing broken starter motors or damaged battery cables in this scenario.
If a truck comes back into the shop for periodic maintenance, technicians should make sure they test each battery. You will want to make sure the batteries are strong before the truck driver ends up in a no-start position on the side of the road.
After the vehicle is started, a voltage meter can be used to indicate if enough voltage is coming through. Battery terminals should always read between 14.00 and 14.40 volts. The alternators should also provide power within this range. An appropriate charging system should also operate at 14.20 volts. Actual amperage output may differ depending on the system you use.
How to Reduce Battery Problems
One of the most common mistakes a technician makes it to use the incorrect charging method for the battery type. Old linear chargers may apply a voltage greater than 15.00, which is not recommended for modern sealed batteries. You may wind up overcharging the battery and losing the electrolyte. The best thing to do is invest in a “smart charger.”
Smart chargers usually can sense the condition of the battery and adjust their charge accordingly. Advanced models contain a charging algorithm that reads the desired output during the charging process. Still, the charging method won’t matter if you aren’t properly maintaining your battery. The best way to avoid high cycling with deep discharging is to use large amperage alternators. When you have a vehicle in for a maintenance cycle, make sure you bring batteries back to full charge. You should need to do this twice a year.
You also want to check rested voltage value. If a battery is failing, you can generally discover the problem when you test it at rest. It also isn’t bad to invest in high power charging systems that handle the job quickly and fully.
North American motor carriers should ensure they are creating an atmosphere of preventative maintenance for their shop technicians. Whether it be through the proper care and maintenance of seals or keeping fleet batteries in tip-top shape, proper consideration must be paid to prevent vehicle downtime.