Hello! I am looking into purchasing a 2004 f-150 super cab fx4. I was just wondering, how much rust is too much rust? The rest of the truck looked decent.
What I am worried about is the bed rails/undercarriage. There is rust flaking off in some chunks. Would this be somewhat fixable or work to be done to slow down the rust? Or should I keep looking? I don't have much experienced with trucks as I own two jeep xjs. Any help is appreciated! Thank you in advance.

 

I recently bought a 2003 F250 with 61,000 miles and it has a lot less rust than that, and I treated what little there was with Fluid Film. Your rust is not unreasonable however if the truck is higher mileage, priced right, and intended as a work truck. I had a 1993 that was rusted clear through but still did the work.

 

 

 

Those are the bed support crossmembers. They can be rebuilt/replaced, I just did that on my Ranger last August. Not too bad of a job if you have the right tools to remove the bed, cut the olde ones out, and do a little spotwelding, and time. Then undercoat the snot out of it, especially the insides of the crossmembers.
I used the loader on my tractor to lift the bed off, but I work totally alone. Get some buddies, unbolt, disconnect harnesses, pick it off, flip over and go to town.
There are bed floor replacement panels out there as well if you run into any bad spots on the floor. Or, do a "redneck" job, and throw a dropin liner in there.
Just depends on the rest of the truck, as in, is it worth it?
Those supports, from the photos, are on their way out, but you've got awhile yet. Take a narrow, long stemmed flathead screwdriver, and get to poking.

 

What are your intentions of the truck? Work truck, beater, keeping it for a long time, family vehicle? All vehicles rust depending what they were used for and where in the country.
Use your gut feeling. But if you have to ask that question, keep looking since you are hesitant.

 

This is great advice, if at all hesitant it's time to start looking for something else. Most likely you will always wonder in the back of your mind if you made the right decision after buying it due to the excessive rust.

 

You better never drive your truck in the rain. Really, who cares about rust on iron UNDER the truck.
Ever look at your rotors if your truck sat after a good rain?

 

The OP has never been back since he started this Thread, in March.

 

There are many one-and-done posts. Many are not as valid a concern as this.