Just looking for some input regarding best type of line or hose to use. Discovered this weekend that the brake line that runs through the tube frame on my trailer is either cracked or worn through somewhere inside the frame. It is the standard steel line with flared ends. I guess due to the current situation I am hesitant to use that type of line again. Would rubber brake hose hold up better inside the frame than steel? Any drawbacks, pressure loss etc? Is roughly 23 feet between connections, with an s bend on one end and a 90 sweep bent on the downstream end into the distribution block.

Copper nickel brake line. All parts stores carry it in many different diameters. Its bends very easy and doesn't really corrode.

Typically available in 25' and 50ft lengths.

We do tons of brake lines for vehicles up here (heavy salt in winter) and use this all the time.

Edit in: I see you are in Michigan. Another heavy salt area in winter. Your stores will definitely have it.

And you are confident it will hold up bouncing around inside the tube frame? Seems like a copper alloy would be more prone to wear against steel than normal steel or stainless. Not concerned about corrosion much trailer does not get towed in winter at all, kept inside.

Then slide some flex tubing over it or every ft some shrink tubing or zip tie (around the tubing itself - I realize you can't connect it to anything else) every 6" or something.

It's great stuff. You will love working with it.

Edit in: Again, we all have opinions, and this is mine.

I had the same thing happen, and didn't try to fish it down thru the frame. I cushion-clamped it outside of the frame tube, down the boat-side of the trailer. I couldn't see the point of running it inside and having the same thing happen again, on the outside it's not noticeable and is easy to plumb and inspect.

I did have to go under the crossbeams, but I haven't had any issues in the 9 years since I did it.

Thought about doing that but should be a non event to pull it back through with existing line when it comes out. Plus hate drilling holes for clamps in a nice tube trailer, more places for rust to start.

Can buy the flex hose with ends attached for less than a bending or flaring tool will cost. Just worried about longevity of it.

Just replaced master cylinder, reverse lockout solenoid and brake line from front to back. Used Kodiak flexible hose. Attached the new hose and old hose with threaded brake line connector and pulled it through with ease. Any contact points I used a piece of 1/2" split loom to protect it. I do like the flexible hoses. Much easier to work with. Line was run in about two minutes and hooked up ready to bleed in less than 5. Just don't try to bend the SS part of the line and fitting. Don't ask.....

The stainless steel coils are pretty easy to work with too. I replaced the line on my 26' Sonic's trailer years ago with SS coil from Champion Trailer Parts (online). I agree with lacing it though some clear silicone hose you can get from Home Depot or Lowes.

May not be an issue but a long length of rubber hose may have a tendency to swell under pressure. I know we tried braided hose on a race car years ago and the pedal was a bit mushy until we switched over to solid line except the very end. Obviously there's no pedal associated with this so you won't feel anything but none the less I would think a solid line will transmit the pressure better.