Like most fluids in your vehicle the transmission fluid in your car can overheat. The transmission cooling line is the part of the transmission system that can help lower the temperature of the transmission fluid and extend its life while keeping your transmission safe and functional. As the transmission fluid passes through the transmission system it's going to get hotter and then it circulates back through the cooling lines into the radiator to cool down again. So, if there's a problem with this line, such as a leak or break somewhere then the cooling can't take place the way it's supposed to. If you're looking to get a transmission cooling line repaired, it's probably going to cost you anywhere from $100 to $500 to get the job done.
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The fairly large range of cost associated with getting your transmission cooling line repaired is because of the variation of labor costs that exists between one mechanic and the next. As you know, you could get three different quotes from three different mechanics in town for the same job. Likewise, the make and model of your vehicle also have an effect on these costs. And finally, where exactly in the cooling line you have a problem it's going to have a major effect on how much you have to pay to get it repaired as well.
If you're interested in simply getting the line yourself to do a DIY repair, you can pick them up over on AutoZone for only $15 to $50 or so. Your only concern at this point is that you get the exact right lines to fit your car as not every cooling line is going to fit every transmission by any means. Maybe just pissed just keep torches
What Causes Transmission Cooler Lines to Leak?
There can be mechanical reasons why your transmission cooler line is failing related to the connectors and gaskets being faulty but that's not typically the reason. The most common reason for your transmission cooler line to fail is just because of general wear and tear. Your transmission cooler line has to operate under high heat for a very long time, and eventually any line is going to wear it and what it has to deal with the high temperatures and stress that a transmission cooler line is meant to undergo as part of its normal operation. Typically, this will be visible so that you can see the rubber portion of the hose begins to deteriorate and form cracks or crumble apart.
Signs and Symptoms of a Bad Transmission Cooling Line
If your transmission cooling line isn't working the way, it's supposed to then you're going to notice a few problems crop up to let you know that there's a problem. If you're experiencing one or more of these symptoms, then you'll definitely want to take your car to a mechanic to get it properly diagnosed.
Fluid Leak: This is clearly the most obvious sign that you have a problem in your transmission somewhere, that's if you have noticeable transmission fluid leaking from somewhere. Transmission fluid is typically red when it's still in good working condition though it will get muddy and dark if it's old and contaminated. If you see red fluid puddling under your car after you've been parked, or if you can see it under the hood of your car building up around any gaskets or hoses then it's likely you have a problem with your cooling line somewhere. Check where the lines connect to the radiator because that is a common place for leaks to occur.
If transmission fluid is contaminated and the colour is hard to identify you could try parking on top of something like a sheet of paper or cardboard. This will allow you to give it a closer visual inspection later so you can help it be separated from any dirt or oil that may be on the ground already causing you to misidentify what's leaking from your vehicle.
Misshapen Lines: A visual inspection around your transmission and especially the lines heading from the transmission to the radiator may give you some indication that there was a problem. For instance, if you see cracks, holes, and bulges in the lines then you know there's a problem as none of that should be happening.
Fluid Levels: Some transmissions come with a dipstick that allows you to check the transmission fluid levels. Not every vehicle has this, but if yours does and that's a simple and easy way to check the levels of fluid. If you're finding that your transmission fluid level is very low, then you very likely have a leak somewhere.
Noises: If your transmission fluid levels are low then the fluids are not going to be able to properly cool and lubricate your transmission the way it's supposed to. That's going to lead to squealing or grinding noises when you shift through gears. This may be most noticeable on Startup, or as you shift into neutral or park for instance. These noises will get worse the longer this continues.
Difficulty Shifting: You will find as you try to shift from one year to another if there's a problem with your transmission overheating or the fluid levels being too low that shifting from one gear to the next becomes a struggle. It may seem like you really have to force the shifter to get into a new gear. Just as likely as the potential for you to slip from one gear to another unintentionally. This can be extremely dangerous if it happens while you're driving and your car switches from a high gear to a lower gear for instance affecting your performance. If you're travelling at a high rate of speed on the highway surrounded by other vehicles, this could lead to an accident.
Burning Smell: If there is a leak in your cooling line and your transmission fluid gets low enough it may produce a burning smell coming from the transmission as well. Because the transmission is prone to overheating now that there is a cooling line leak, the lower levels of fuel can actually start to burn and thicken up in the system. If it gets bad enough your transmission fluid can go from the normal red colour to nearly black. This can cause serious damage to your transmission in a fairly short amount of time.
Is it Safe to Drive My Car with a Transmission Cooling Line Leak?
As we've seen there are a number of potentially problematic side effects to having a leak in your transmission cooling line. Although you might be able to drive for a while they're getting this repaired, especially if it's just a small leak, the fact is that any leak will continue to get worse over time and your fluid levels will drop to a dangerous low. This can end up causing severe problems with your transmission. If it gets bad enough your whole transmission may seize up and the cost of replacing your transmission can end up being thousands of dollars if it gets that bad.
Fortunately, a transmission leak is an early warning sign that this is going to happen so there's no excuse to ignore it when it's still manageable. It's always a better idea to repair something when you first notice it and it's still affordable then to wait until the problem is so severe it incapacitates your entire vehicle and ends up costing you a lot more money.
How Long Does It Take to Replace Transmission Cooling Lines?
Getting the cooling line in your transmission repaired can be a time-consuming job. Transmission repairs often take a day or two at the mechanic depending on how extensive they are. That's due in no small part to the fact that transmission systems are much more complicated in modern cars than they were in older cars. The length of time it takes your mechanic to get this job done depends on the nature of the leak that you have and how thoroughly they're going to inspect the rest of your transmission and conduct any potential repairs if necessary as well.
Can I Fix My Own Transmission Cooling Line?
As we said, you can pick up new transmission cooling lines on AutoZone at an affordable price. This is the best option if you've noticed that the line itself is completely broken or badly corroded where it connects. if you have a small crack or leak somewhere else in the line at a connector then you can also potentially use a kind of sealant. There are liquid sealants that you can buy as well as things like Teflon tape that only cost about $3. This is not a permanent fix by any means, but it can definitely stave off the worst of the leak for a while until you can find a more permanent solution.
If you are doing your own repair and bought a new line, it never hurts to use a bit of Teflon tape on the threads when you connect the lines as well just for some added protection to ensure that it says secure seal.
You can also buy adapters that connect to the end of the line at either the radiator or the transmission end that may improve the seal at either of those locations. These are also very cheap, and you can probably get them between $5 and $10 at AutoZone or other places that sell auto parts.
Most transmission cooling lines are made from steel or aluminum composite lines. You can find videos online that advise you on how to replace these with much cheaper rubber hoses which are affordable and flexible to fit into tight spaces. It's possible that you could use a rubber hose to fix your transmission cooling line, but you really need to do your homework on this one.
Not every rubber hose is suitable for this job and because transmission cooling lines may have to deal with transmission fluid that reaches temperatures up to over 300 degrees, you need to make sure you've got a rubber hose that's specifically meant to handle transmission fluid at high temperatures. If you grabbed the wrong one it could end up melting quickly or starting to leak or bulge because of the pressure that the fluid is under as well.
If you use the wrong rubber hose that's not designed for a transmission fluid it may still work for several weeks while you're driving but could potentially fail without warning very soon after it's been installed. This happens while you're on the road your transmission could fail almost right away as you lose all your transmission fluid. That's definitely a danger you don't want to risk so make sure any line you pick up is designed specifically to handle transmission fluid.
There are steel braided and nylon braided lines that are made with rubber as a base but have these added materials to increase their durability. These are much more likely to last and then a plane rubber line.
If you are interested in managing this as a DIY job, it's not really that complicated compared to some repair jobs you may have to do. The best thing you can do is look up a video like this one that can guide you through the process of getting the transmission cooling line swapped out. That way you can see firsthand how it's done.
The Bottom Line
Transmission cooling lines are of vital importance to ensuring that your transmission functions properly. Without it your transmission will overheat very quickly, and minor damage can grow into severe damage very soon. Your entire transmission failing is the end result of the inability to keep your transmission cool, so you can definitely see why having a properly functioning transmission cooling line is important to the overall function of your car.
Leaks are going to be the main visual indication that you have a problem with your transmission cooling line. Transmission fluid should never be coming out of your vehicle, so if you see that red liquid even just a few drops under your vehicle or under the hood somewhere, then make sure you take your vehicle in to get inspected by a mechanic as soon as you can. The longer you let this one go, the worse it's going to get.