Are you concerned your trailer brakes may freeze during the winter? In mid-winter, when temperatures can drop well below zero in the northern part of the country, frozen brakes can be inevitable without the proper precautions. I can’t help but worry about my brother, a long-haul driver frequently traveling from Minnesota to Washington state. He’s told me tales about frozen brakes.
So, how do you keep trailer brakes from freezing? You can keep your brakes from freezing by checking you air dryer filter, rocking your truck before you stop for the night or draining your air tanks.
There are several more ways to keep your trailer brakes from freezing. Below we go into those techniques. We also help you out with some tips on how to deal with frozen brakes.
Can Trailer Brakes Freeze?
Trailer brakes can and will freeze when the temperature drops low enough. What are things you can do to keep your trailer brakes from freezing? The best way to keep trailer brakes from freezing is to drain the air tanks every day. Draining the air tanks will prevent moisture from accumulating in your system and causing your brakes to freeze.
Less frequently, it could be that instead of moisture in the air tanks, your brake shoes are frozen to the drum. Read on for tips to prevent your brakes from freezing.
6 Ways to Prevent Your Brakes from Freezing
Even if you have an air dryer, moisture will accumulate in your air tanks. If you’re traveling in areas with extreme temperatures like, Minnesota in February, you’re in danger of brake freezing.
Check Your Air Dryer and Filter
Your air dryer is a crucial part of keeping your brakes from freezing. When it’s working properly, your headaches decrease. When you drain your air tanks, notice the amount of water draining out of the lines. If it’s a large amount, or it seems to be increasing with time, it is a good idea to inspect your air dryer. Your air dryer, installed properly, should be getting rid of most of the moisture in your air tanks. Braking systems use compressed air. A small temperature drop will cause condensation to form. This can happen throughout the system
If your air dryer doesn’t seem to be working properly, first check the air filter. Change it regularly in accordance with the manufacturer’s recommendations. Many truckers change their filters in the fall, when there is a higher dew point.
If your filter seems to be fine, you may want to disassemble your air lines and valves. Check these carefully for leaks or wear and tear. You should be taking these apart twice a year and blowing them out with an air compressor.
If you see wear or tear on any of these components, replace them immediately with genuine replacement parts. Brake performance could change if you use off-market or shoddy parts.
Keep Your Evaporator Filled with Air Brake Anti-Freeze
Alcohol evaporators are often optional devices on trucks, but it can come in useful, especially in colder climates. An evaporator, or alcohol injector, will introduce a small amount of alcohol vapor into the air system. The alcohol combines with any moisture that may be present and acts as an anti-freeze. This lowers the freezing point of any moisture that is collected in the system.
Make sure you keep your evaporator filled with methyl hydrate. This is specifically formulated for use in alcohol evaporators so don’t deviate. Check the level on a regular basis.
“Rock” The Truck Before You Stop for The Night
When moisture builds up inside your air lines, it’s not a good idea to stop for the night and let it freeze. This also applies if your brakes are wet. Wet brakes in cold weather are almost guaranteed to freeze up, with the brake shoe freezing to the drum. Some operators swear that “rocking” a truck will “break” the ice up and free your brakes. Rocking the rock entails:
This will dissipate the moisture inside the lines before you call it an evening. Some even drag the trailer brakes before this step to reduce the moisture.
We don’t recommend dragging your trailer brakes intentionally. This can cause friction and lead to a truck fire. However, rocking your truck back and forth before draining your air tanks is a preventive measure that won’t hurt and may actually help.
Avoid Idling Your Truck for Long Periods
We get it. Sometimes you’re stuck in traffic and there’s no choice, you must idle your truck. However, do not allow your truck to idle for long periods if you can avoid it. Idling for long periods can lead to compressor discharge and make the line freeze-up. You could even harm your compressor.
When Possible, Park Indoors
This one can be a bit of a problem. Not many truck stops offer indoor parking for trucks. But, if you have the opportunity to park your truck and trailer indoors, take it. Make sure you leave your drain valves open overnight to dry.
Drain Your Air Tanks Every Day
Drain your air tanks every day. Normally you will want to do this when you stop for the night. However, if you’re having a problem with large amounts of water coming from your lines, you may want to do it multiple times a day. If you do see large amounts of water, your air dryer may not be working properly. Make sure to service your air dryer, as noted above.
For moisture in the air line, this is the number one preventive measure to protect yourself and your trailer.
PRO TIP
Make sure there are no
kinks in your discharge line. It should slope downward from the compressor
discharge port to the supply reservoir. Having a kink in the line or having it
slope upwards could cause water traps which could freeze and harm your entire
system.
5 Solutions If Your Brakes Do Freeze
So, you’ve forgotten to drain your tank lines and you’re looking at a frozen valve. Or, you’ve set your brakes in park while they were wet and now you have a brake shoe frozen to the drum. Fortunately, you have a few options. None of them are fool-proof and a couple can be dangerous. They include:
Tap Your Brake Drum with A Hammer
If your brake shoes are frozen to the drum, one of the ways to correct the issue is to get under your truck and tap your brake drum with a hammer to break up the ice. This can be very dangerous and can also ruin your brakes. The most important thing you’re going to do first is to lock your tractor brakes.
In a truck stop in the Northwest, my brother found himself with his brakes locked tight. Without locking his tractor brakes, he crawled under the truck. When he broke the ice from his last locked brake, the truck started rolling. Trapped under the truck, he could only watch helplessly as the huge rig moved right above him. Thankfully, the truck rolled only 10 or so feet and he was unharmed, but it could have gone a lot differently.
To break the ice from the frozen brake drum, you can use:
Whatever you use, be careful not to hit the brake pad directly. Brake pads can crack or fracture easily. You can also use a wooden “pad” between the hammer and the drum so you’re not striking the drum directly. Strike the bottom and the top of the drum. Hitting the brake drum makes a different sound when the drum is frozen than when it is not, but you have to have some experience doing this in order to sort out which is which.
Thaw Out Frozen Air Lines by Placing Truck in Warm Building
Really, the only safe method for thawing out frozen air lines and valves is placing the vehicle in a warm building and letting them thaw naturally. This takes more time but is the safest, smartest option.
Cut Air Supply and Resupply Multiple Times
The best solution to frozen brake lines is not to get under the truck at all. Sometimes just cutting off the air supply and cutting it back on is enough to jar the ice enough that it comes loose. This is most often effective when only one brake drum is frozen to the pad. Try this before crawling under the truck.
Use Methyl Hydrate or Washer Fluid on Your Brake Drums
Some operators swear by a spray bottle of methyl hydrate or washer fluid. You can buy methyl hydrate at a big box or home improvement store. It’s basically wood alcohol. The methyl or the washer fluid can melt the ice on the shoes.
A couple of precautions – make sure you aren’t around open flames with either the methyl hydrate or the washer fluid. Do not smoke around this stuff! It’s extremely flammable.
If you can spray the methyl and it sufficiently melts the ice to a point where you can get the brakes unlocked by rocking the truck back and forth, you’ve saved yourself a trip under the truck.
Use A Small Torch to Melt the Ice
There are some operators who disagree strongly with using a hammer on truck brakes. Their point of view is that it is too easy to damage the brake pads with an errant swing. You can also damage the brake drum itself if you swing too strongly.
An alternative option is to jack the wheel that’s not turning and apply heat to the drum with a torch. Heat the drum evenly and don’t get it too hot. You only want to melt the ice between the drum and the shoe. This has its own problems, though. This can be dangerous! It only takes a second to burn through an air line. Anytime you’re using open flames near your truck, you need to take extra precautions. DO NOT USE A SMALL TORCH WHEN YOU ARE USING METHYL HYDRATE OR WASHER FLUID!
We Don’t Recommend
There are many operators who will tell you to open the air supply line and pour air brake anti-freeze directly into the line. Some operators will state that you can pour rubbing alcohol into the brake line itself. The theory behind this is that the chemicals will cause the ice to melt and the water to evaporate.
We don’t recommend either of these options. Those products can cause the rubber seals in the valves to swell and harden and eventually leak. You could end up causing yourself more problems in the long run. They may also take a long time to work.
SAFETY TIPS FOR CRAWLING UNDER
YOUR TRAILER
Lock your tractor brakes but do not lock the trailer brakes. You’re trying to loosen the trailer brakes and locking them will hamper that. Other items to keep in mind are:
When you park for the night, always try to park on level ground. This is a good habit to get into, regardless of the season. If you find yourself in a sticky situation and need to get under your truck, it helps to know that you’re not on an incline. Even with the tractor brakes locked, your truck can slide on even a small incline during icy weather. Best not to chance it.
Increasing your air pressure by 5 pounds through the compressor governor can sometimes be enough to loosen the frozen brake shoes. It may not work every time but it’s worth a shot before crawling under the truck.
Another idea you can try is to see if you can “break” the frozen brake shoes. Try to put your truck in reverse while letting clutch out to force some rearward pressure. Now set your tractor brake. Then build up your air pressure and apply heavy brake pressure. Hold the pedal for a few seconds. Repeat three times. Sometimes this, by itself, can break the ice bond on the drums. However, don’t be too rough on your truck. You can break good equipment by being too rough on it in this manner.
If nothing else has worked, you should consider your safety before getting under the truck. You’ve locked the tractor brakes and you’ve left the trailer brakes unlocked. Consider an extra safety measure. If you have room, carry around a couple of short 4x4s, longer than the width of your tires. Place them behind the tires for extra protection.
Even with all the safety precautions, make sure you’re not in the tire path when you get under the truck. Especially on slick ice, those trailer wheels can move quickly. Approach the brakes from one side or the other, never with your body directly behind or in front of the tires.
Tips from The Road
Operators have a lot of experience dealing with frozen brakes and they are not shy to voice their opinions. Here are some dos and don’ts straight from the experts themselves.
Freeze Prevention
- Before you pull into the truck stop for the night, put a little pressure on your brakes and heat them up to dry them off. Make sure it’s just a little pressure.
- After sitting for a minute at your nightly stop, move the truck back and forth a foot in each direction to pack snow down so your tires aren’t frozen to the ground in the morning.
- Keep a tube of sand in your truck. If you find you’ve parked on ice, pull up and throw a few handfuls of sand on the ground and park back over it.
- Do NOT set brakes while they are wet. Let them dry first.
Defrosting Brakes
- Don’t put it in gear and yank on it like a madman. You could break a driveline.
- Don’t drive off and think it will loosen up in a minute.
- Try a gentle tap on the actuator arms if the brakes don’t release after a couple of taps from the hammer on the brake drum.
- Figure out exactly which drum is frozen before you go around working on all of them.
- Make absolutely sure the tractor brakes are set or use a wheel chock.
- If all the wheels on the wheel group aren’t moving, investigate a frozen valve.
- Never add airline antifreeze to the service line.
- Alcohol kills ABS valves.
