Hayden Automotive 397 Transmission Line Fitting Kit

Worked awesome for flushing my transmission

Changed the fluid and filter in my Silverado. This fit right in the return opening at the radiator and let me use a nylon hose to route the fluid to a bucket. Made dropping the trans pan a lot less messy.

You need this for flushing transmission fluid. Worked on my Silverado and Wrangler. The wrangler transmission has arrows cast into it so you know which line to plug into at the transmission!! Just need clear tubing, a clear bucket and, lots if fluid. Sealed securely with no leaks. Make sure to weigh the hose thats in the bucket or else you’ll have transmission fluid everywhere!!!

Replace cooler line on top left of radiator (left when facing the grill of the car). Use 3/8" ID clear tube. Start engine (in park) and let coolant flow out for up to 10 seconds or so. It's recommended you measure what comes out and put the same back in to avoid the problem I'm going to describe later. Turn the vehicle off. Fill the transmission back up. Repeat. You can also run the engine until you get bubbles in the line, shut the engine off, remove the pan and not have fluid poor all over your face (I could not remove my drain plug for the life of me). Now, don't do what so many people do after a fluid swap and assume that the dipstick is right the first time after all of this effort. It won't be because the fluid will be aerated and/or not fully filling the torque converter yet. So many people think their transmission slips after doing one of these fluid swaps but don't realize they haven't filled it back up all the way. You will be dumping a bunch of fluid - like 3 gallons. You need to get 4 gallons at least for the swap to replace all the fluid for real and be able to refill the transmission to full. In order to get the dipstick to read right, you need to fill it up, check, run the car through the gears, maybe even let it move a few yards back and forth, then check again. Do this a few times. Then when you get home or to your first destination, check again. If you experience slipping after doing this swap, it could very well be you haven't put enough fluid back in. The dipstick lies after an invasive swap like this, especially when you don't measure what you take out and replace with the same. How do I know this? Because I've helped a few DIY'ers who panicked thinking their transmission failed after the swap (because you hear this happens "all the time") and it turns out they just never checked the fluid after the first attempt. Luckily nobody destroyed anything because they didn't drive very far. Be smart. Measure what you take out.

I bought this fitting to help my do a complete transmission fluid flush in my 2012 GMC Sierra 1500. I removed the trans cooling return line from the top of my radiator and installed this fitting. I then attached some clear tubing to the other end of the fitting that ran into a 5 gal catch bucket. I had a helper start the truck and I added new fluid down the transmission fill tube as the running engine pumped the old fluid out. When the fluid in the clear tubing changed from dark red to bright clear red, my helper turned off the truck. I then removed the fitting and replaced the trans return line to the radiator. After running the truck again and shifting the transmission through all of it's gears I topped off the trans fluid according to the dipstick. If you are thinking of doing this I highly recommend getting the OTC 7937 disconnect tool (also here at Amazon) as it makes removing the cooler line retaining clip much easier. And DON'T loose the clip! It's very easy for it to go flying as you try to re-install it. Using this fitting I didn't spill a single drop of fluid. Definitely with $$$.

Worked good for draining and refilling transmission fluid on my 2011 DTS. Price is a bit high however

I used this every time I do a complete ATF flush in my GMC Denali Yukon.

This Hayden transmission fitting is the way to flush out your old fluid completely, by yourself. Used it on my 2007 Silverado 2500 HD.When you remove your transmission pan to change the fluid,filter & gasket,there is still dirty fluid in the system.This fitting is exactly like the oil cooler line hose to your transmission.I disconnected the line in my truck & put this fitting there.Connected 10' of clear hose to it & clamped the other end into a 5 gallon bucket.The clear hose used is 3/8 ID,which slides onto the fitting.The 10' allowed me to place the bucket by the driver's door so I could start the truck & see the fluid pumping out.When it starts to slow down,shut vehicle off & replace fluid,repeat.I did this with 4 gallons of transmission fluid at 110,000 miles.Each flush,the fluid gets cleaner.Never realized how dirty my fluid was till I did this.When you are done,remove the fitting & reconnect your line.Make sure the O ring is good when doing this.