Common Roadside Service Calls - Part 1: Gel Ups | Semi Truck Repair

Finally, it’s winter.

Thanks to temperature variations caused by El Niño, the cold season reared it’s ugly head considerably later than usual this year in many parts of the US.

Yes, Midwesterners, we did actually hear you singing hallelujahs to the heavens in grateful thanks for this fact. No, we would not recommend changing careers. 🙂

Last winter, we pulled historical data from our roadside service calls and found that out of 4,812 calls we received from December through February of the prior year, 40% of them could have been avoided, most very simply by the use of more diligent preventative maintenance practices throughout the course of the year.

For those of you that missed that post – 40% is not a gross exaggeration nor any use of poetic license. That number comes directly from the data we collated from all of our calls. (Yes, we really are anal retentive like that.)

Several of our bigger fleets took notice of last years post and started routing all of their equipment through a much more structured preventative maintenance program. They are already forecasting this winter’s costs to be significantly lower as a result.

For those other fleets that figured we were just blowing smoke out our stacks??

Well… we’re pretty sure they’ll be sick of calling us by seasons end; let’s just say that.

Just as hot summer pavement is an enemy to tires, cold winter temperatures are no friends to diesel engines and their components. And while we could preach 1000 sermons on preventative maintenance to 1000 choirs here, we’re not going to. This year instead we thought we would break down the most common calls we receive, shed some light on how and why they happen, and then…. well… you know… just suggest a few best practices that might help to stop them before they’ve got your driver and your equipment on the side of the road paying us for a service call.

The first common roadside service call we are going to tackle today is the gel up. A gel up occurs when the paraffin wax (found naturally in grade 2 diesel fuel) gets so cold that it starts to form waxy crystals within the fuel. These crystals quickly build up and clog the filter, depriving the engine of fuel, thus causing a no start. Paraffin crystals in this type of fuel also result in clogged fuel lines, which produce the same effect.

Preventative maintenance here is key. Once the paraffin has gelled up on the filter, your truck is going to have difficulty starting, if it does at all. And, once this happens, your only solution is getting someone out to that truck for a repair. (Which will obviously be us or you… at your expense either way.) Standard practice is simply to switch out the fuel filter and add Diesel 911 to the tank. The fuel will flow freely through the new filter and the additive in the fuel will help break up any build up in the lines.

Sounds easy enough when it’s typed out like that, right?

Of course. But downtime and dock appointments and all the rest are affected. The bottom line? Your bottom line is affected.

We recommend switching to grade 1 diesel fuel or a winter blend before the “dang near teen temps” hit. The “cloud point,” or temperature in which the paraffin begins to crystallize, ranges anywhere from 20° F at the warm end to -15°F at the coldest. And, if you’re living in an area where temps fluctuate frequently, you could even find yourself with a no start due to a gel up with temperatures that are higher than that. So, when the temperatures start to drop, and you’re getting out hats, scarves, and gloves to compliment that coat, it’s time to make the switch. Yes, grade 1 diesel is expensive. But so is a service call while your truck sits.

Other people, without consistent access to grade 1 fuel, can choose to safeguard their truck by using fuel additives before every fill up during the winter months and regularly running their trucks instead of allowing them to sit for extended periods of time in cold climates. Either route you choose, it’s best to start thinking about it before those freezing temperatures hit. And if you haven’t yet, do it now. Your driver, your watch, and your wallet will thank you.