Anyone have the trans cooler lines rot out. Mine rotted under the radiator and had to be replaced. I would think this is more common in the northern states. All that salt on the roads in the winter.

I replaced mine a month ago when I changed out my transmission fluid. The lines never broke, but they looked like they could at any time. It was an easy swap. The metal lines with bracket set me back about $70 from my dealer.

Trans lines, fuel lines, brake lines.
Had one or another rust out on all my trucks at one time or another.

I replaced mine in January. They were rotting out and you could see some signs of leaking on the lines themselves. I changed out the lines under the radiator. Washed off the power steering line and coated it in rustproofing paint...

Yup. I had to replace those on my '03 last year.

Within the last year, I have had to replace both the transmission cooling lines that run along side the engine, the return line from the steering rack to the pump, and had both front frame extensions repaired and the front aux cross member replaced. These Toyota's are not built to withstand the Northeast winter road conditions.

I'm pretty sure any vehicle dunked in salt for 12+ years is not going to come out the other end without corrosion issues.

It might be worth it to go with aftermarket stuff like PTFE AN hose, or even brass fittings to rubber lines the whole way. No corrosion worries then.

I had the entire frame replaced on my '03. Hang around a while and a fellow will be along to tell you that the reason yours rusted is because you neglected it.

I am fully aware of the issue with the use of road salt in the Northeast. But, the amount of rust damage I have seen on both my 4Runners is way more than any of the other vehicles I have owned in the past. My wife has an '02 X5, with 142k, and with the exception of one brake line rust failure, is in way better shape than either of my 4Runners. And, the brake line failure is because of a specific part failure that only the X5's use. No other BMW's of that vintage have this level of rust damage.

Given the documented problems with Sequoia's, Tundras, Tacomas, and what others have reported about their 4Runners, it appears, IMHO, that Toyota design wasn't prepared to deal with the winter conditions in the North.

I worked as a Tech at a Honda Dealership in the early 80's, and Honda had a Major rust problem with frames and suspension components back then. Honda went through a series of recalls to repair/replace damaged components for a few years. But, they learned their lesson, and subsequent vehicles were a lot less prone to rust damage. Toyota cut corners, IMHO, for cost reasons and we are suffering the results.

You can't design enough cathodic protection into something like a brake or transmission line to make a difference in long term corrosion resistance in a salt/oxygen rich environment.

The difference between your X5 and the 4Runner is probably 95% down to having the underbody and wheelwells sealed much better to avoid the salt spray situation on most components in the first place.

A BOF design like the 4Runner doesn't really lend itself to enclosing things off like you can in a unibody design.


Most trucks/BOF SUVs have similar issues for similar reasons.


But cost is one of the reasons. For another $50 per car, they could go with a Cu-Ni-Fe brake line and not have corrosion issues with it. But as long as everybody uses much cheaper coated steel lines, it's a tough sell, because where do you stop? You add $50 to the cost in 20 areas, and now we're starting to make a big change to the price of the vehicle.

I understand that one might think the underbody covers would help shield the lines and other parts form salt spray, but the line that failed was under the driver side seat, well within the 'protected' area. As the BMW tech noted, the covers do afford a degree of protection, but they also prevent an underbody/spray wash from rinsing the area clean. And I do understand that every potential problem area that is addressed has a cost associated to it. Given the level of corrosion enhancing materials that are present every winter to attack our northern vehicles, I can live with the transmission/brake line failures. But the amount of frame failures is another thing. I can replace transmission/brake lines fairly easily, at an acceptable cost. Not so with a failed frame. It sucks to have to consider junking a 12 year old vehicle that, except for the frame, is still in very good condition.

I know about the rust problems all too well. I was a Toyota service manager for 10 years and dealt with many frames that were rotted. The thing that pissed me off was my rep telling me that a customer with a rotted 4Runner frame they were not going to help. His words were "We are going to stone wall them until they go away"!!!! What BS from them with all the history they have with rusted frames.

Replaced the trans lines today. Rusted bolts holding the line on had to drill and tap and put new bolts. There is a lot of rusted bolts. The frame has rust but nothing rotting through like Tacoma's yet.

Mine are leaking as well. Besides the dealership, where did you guys find your replacements?

I got mine from Partznet, online Toyota Dealer. Original parts, just a bit less than walking into the local dealership. They fit exactly, but it was a bit of a chore snaking them into place while vehicle was only up on jack stands. A lift would have been MUCH easier. Also, you may want to order one or more of the brackets that hold the lines to the side of the engine. Since everything was so rusted, I broke one when trying to remove bolt holding bracket.