So I'm currently in the process of gutting a 2005 E350 (a former wheelchair van with a raised roof) to turn it into a camper van. As part of this process, I went about removing the back heater. In what was probably not the most intelligent decision of my life, I sliced the coolant line just below the heater and looked on in confusion as radiator fluid poured onto the ground (I was expecting to just slice a few electrical wires...).

So... now what?

I'm searching all over the place for some kind of diagram of the cooling/heating system to figure out where the hose I cut goes. Looking under the hood, it seems to go... places. It would be nice if it were relatively isolated, and I could just pop some caps on the ends of the lines and refill the coolant. Or if it were completely isolated and I could just ignore the thing.

  • What engine do you have?
    – Moab
    Jul 16 '18 at 19:32
  • It's the V10 engine.
    – Textcape
    Jul 16 '18 at 21:48
  • I cannot find any images of where the rear heater hoses connect to the engine, you will just have to follow them visually as suggested by Solar Mike.
    – Moab
    Jul 17 '18 at 16:15
  • Thanks @Moab. That shouldn't be a problem - the reason I was looking for a diagram was to figure out if the lines for the front and back heater were in series, parallel, or just completely independent.
    – Textcape
    Jul 17 '18 at 19:06

The last time I saw a Ford E350 for a coolant leak, I found the hoses crimped at lines at the back of the engine, easily accessible with the doghouse off (literally, closest thing to you as you sit in the driver's floor). You would have to cut the hoses and plug those. You'll have to pull the front seats out first. Don't cut the A/C lines.

  • This seems like a reasonable solution, except the part where the engine had a coolant leak... Was the leak related to the modified hoses?
    – Textcape
    Jul 16 '18 at 21:50

You need to follow the two pipes that went to the rear and cap them off at the front.

A workshop manual may or may not help - if it was a factory standard option it will, but if a custom build then it won't.

You could just cap both of those hoses off at the rear, but they may become a problem later when fitting other things... At the very least they are a potential leak...

  • If you can't find where to disconnect the hoses at the source ai would get a double hose barb and just connect the ends together. If you just plug them you don't know if it will affect the front heater.
    – mikes
    Jul 16 '18 at 10:06
  • They still continue to be a leak risk...
    – Solar Mike
    Jul 16 '18 at 10:22
  • I agree there is a risk, however if they can't be disconnected, a loop is less likely to cause the issue of the front heater not working because it is air bound or lack circulation.
    – mikes
    Jul 16 '18 at 18:11
  • I don’t think that they would have put the ftont abdcrear hesters in series ... parallel more likely...
    – Solar Mike
    Jul 16 '18 at 20:06
  • Is there a reason they're more likelu to leak in the back, other than the hoses just being longer?
    – Textcape
    Jul 16 '18 at 21:52

I ended up cutting the hoses under the doghouse and connecting them. Here's what I would do if I were to do this again:


  1. Realize that the rear heater is an integrated part of the van's cooling system, and don't slice the coolant lines all willy-nilly! Realize that the same is true of the rear A/C, and that the A/C refrigerant lines run right next to the heater coolant lines. Realize that the A/C refrigerant lines contain high pressure, toxic, environmentally destructive refrigerant and you do not want to cut them.

  2. Realize that because the rear heater is integrated with the engine cooling system, the majority of the work here will be modifying the cooling system. Removing the actual heater is really just a side note.

  3. If, like me, you bought this van used specifically for converting it to a camper, realize that this is probably a good time to flush the cooling system anyway. Likely, the previous owner did not keep meticulous records of vehicle maintenance, and you have no idea when the coolant was last changed. You want your van to break 1,000,000 mi, right? It will likely be impossible to remove the heater without losing most of your coolant anyway, so you might as well do it now.

  4. Realize that this will take a fair amount of time - mostly while waiting for coolant to drain or heat up during the flushing procedure. If, like me, you are converting a used van into a camper, you can use this time to perform other tasks like gutting other parts of the van or removing rust.

  5. Realize that this will be messy and mildly dangerous. Coolant is toxic, and draining the radiator, the engine, and the hoses will inevitably result in something of a coolant bath. Wear clothes you don't care about, make sure there is something around you can wash your hands with, and wear safety goggles - this stuff will get everywhere.

  6. There are a lot of instructions on the internet on how to flush the coolant. The steps are, from a high level view: Drain, Clean/Flush, Refill. You will perform the Drain step, then remove the heater, then finish with Clean/Flush and Refill. There is a religious schism on the internet about whether you should/must use the manufacturer's recommended coolant or if third party coolants are fine, and further, when some third party coolants are fine and when they will destroy your engine. Good luck figuring that out.

  7. The coolant goes from the main system, down the length of the van, to the heater, and then back up the length of the van to reunite with the main system. You have a choice between capping the ends of both lines or splicing them together, but it doesn't really matter which you choose just as long as you don't end up leaking coolant.


I won't make an exhaustive list here, since most of the tools and materials are fairly common. But here are some notes I would have found helpful:

  1. Make sure to have a bucket, preferably two, on hand at all times. Coolant everywhere.

  2. Make sure to have safety goggles on hand at all times. Not only will they protect your eyes from coolant splashes, but they'll help in keeping dirt and rust flakes from falling in your eyes while you slither underneath the van.

  3. Buy a lot of distilled water. It's cheap, and flushing, cleaning, and refilling will take more than you expect.

  4. Before you start, find your engine block drain plugs. On my model, they are about 2 inches above the oil pan at the back of the engine, on either side (though accessing the one on the passenger side will require you to remove the starter). Also on my model, they are not standard bolts, but bolts that screw in flush with the engine block with a hex key. While a standard hex key might work, I found it much easier to use a hex bit on a long-handled ratchet with an extender. The hex is 5/16" on mine, though if the bolt has rust, you might have to dig a little to get it to fit.

  5. You will need something to cap or splice the coolant lines with which fits their internal diameter. My hoses accepted a 5/8" brass hose splicer I got at Home Depot like this. Don't use plastic to splice or cap the hoses, as it will break after a couple years and spill coolant all over the place.


  1. Drain the engine coolant.

  2. Remove the doghouse. The Doghouse is the big plastic center console inside the van between the driver and passenger seats. There are four latches on it, two on each side, holding it in place. Undo the latches and wiggle it free so you have a clear view of the engine. In my van, I saw four hoses coming from the engine compartment bracketed together at the back of the engine - very obvious after removing the doghouse. Two are for engine coolant going to the rear heater, and two are for the A/C.

  3. Trace the coolant lines from the heater in the back to where they come up through the floor of the van, near the back of the engine in the doghouse area. My van had separate rear A/C and heating devices (I believe most stock vans combine the two into one device), but the heater and A/C lines were nevertheless bundled together for most of their journey up the length of the van. You don't want to cut the A/C lines, since they contain high-pressure toxic chemicals that pollute the atmosphere. My lines weaved around various nooks and crannies as they made their way from the back to the front, so I made sure I was still following the same line by periodically wrapping the line I was following in a bit of tape. I also noted that the coolant lines were black in color, while the A/C lines were light gray.

  4. Grab something you can cut a rubber hose with, and a bucket. Directly underneath the doghouse, slice both coolant hoses. Slice one at a time, and allow coolant in the line to drain into the bucket - even though you drained the coolant before, there is likely still some in the lines that will pour out.

  5. Get in the cab and look in the doghouse area to find the lines you just cut. Pull them up into the cab and cut them to whatever length will work for you - you don't want them hanging down underneath the chassis, but you also probably want them to stay in the bracket they're in.

  6. Either splice the hoses together or cap them. Use hose clamps to secure. You shouldn't need to use any sealant if you got a good fit with your caps/splicer.

  7. Remove the now-useless coolant hoses from the underside of the van. Remember to bring a bucket and wear goggles.

  8. If your heater was independent of the A/C like mine, slice the hoses just below it (with bucket on hand) underneath the van. Use a drill or screwdriver to unscrew it from the body of the van, and slice the electrical wire going to it.

  9. Finish doing your coolant flush. While doing this, make sure the hoses aren't leaking where you cut them (and make sure nothing else is leaking too, for that matter).

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