I have a 94 F250 that has sat for a long time. But from running on Pennsylvania roads and sitting for 10 years, the transmission cooler lines have gone rotten so they leak a lot of fluid. Does anyone know what size line these used? I want to use this as a farm truck but don't know what size line to splice in.

Thanks in advance,
Jake

 

Go to parts store and grab the Ni-copp pre flared brake lines, been a while but I think I used 3/8" on my e4od.

 

Should be 3/8. That line stroker is talking about can be bent by hand if you are careful. You cant make a super tight bend or it will kink but its pretty easy to work with.

 

thanks for the replies. I was debating using brake line or just cutting out the bad parts and going over with rubber hose. Is there a lot of pressure coming out of those lines?

 

There is some pressure bur I dpnt know how much. Maybe 20-40 psi? I have had rubber lines blowoff of a steel lune that was jus cut with no flare or anything.

 

Ahh ok I see. So if I do go the rubber line route, I should flare the lines and maybe double clamp it. Thanks guys for the insight. I'll have to pick up some line and other stuff then this week.

 

You want to use "power steering return line" or that's what gets it done in my local parts store. NOT regular fuel line. Fuel line will hold up to hot pressurized transmission fluid for a while but it isn't designed to and it will blow out sooner or later. Sometimes you can ask for hose saying you are adding an external transmission cooler and you might get the correct stuff that way. Maybe.
Because rusty transmission lines are a widespread problem in northern states (I have no clue which particular state your Washington county is in) the dealerships tend to stock new replacements. Even for older trucks. Usually not cheap but it costs nothing to ask. Hard to find a better and easier fix for rusty lines. Pre-bent to length, correct fittings and everything. A direct bolt-on.
A rather better DIY fix is to buy new line then brass compression fittings. Assuming your current tubing is still pretty solid at the ends you can scab some in and be assured it will last a lot longer than rubber hose for not much more money.
Your standard flaring tool leaves a sharp edge on the edge of the flare which can eventually slice through the hose with movement and vibration over time. I've had pretty good luck using a carefully half-done double flare. Depends on what flaring tool you use. With a good flare there's no need to double clamp.

 

The stock lines were 5/16". The 4R100 changed to 3/8".

 

I was thinking about ordering some transmission hose to seal up the leaks. A good portion of the ends is still good from what I could tell. But I believe this truck has had some parts of the line repaired with rubber hose already. I haven't really looked at the whole set of lines yet. Eventually I can get it turned around to the concrete pad and pull all the lines to inspect.
Thanks for the info. I'll definitely take that stuff into account when deciding on what I want to do.

Here is the link: