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I have a 2002 Express 2500 5.7 with rear heat. I'd like to just plumb the lines out of the system, as one is leaking a bit, and I certainly don't need the rear heater. I can't find anywhere any sort of diagram of these lines so I have some idea what I need to disconnect or what I'll need to bypass the lines before I open it up and start in on it. Internet searches have been less than helpful. Does the service manual show the hose routing?
It will be plumbed in parallel with the front heater. There may be an additional valve on the high pressure side to shut off the flow. I would just cut the hose at the high side and shunt it right to the low side. All this stuff will be on the passenger side of the engine.
I probably should just go out to the junkyard and take the doghouse off one and inspect that, but at the closest place the two out there I know have rear heat I don't think are factory, the 98 the interior is half torn out of and the unit says right on it it's an accessory, not GM. The other is a conversion and a '97. Plus I keep finding little differences on 96-00 vans from 01-02. Even the darn dash face panel is different.
Mine I see some signs of work to the inside parts, it has a middle single seat with a couple of new hold down bolts (has to come out to access left side panel where the heater actually is hidden) and there's a spot that looks to be dried up coolant on the mat. It didn't come with records but I've found a lot of parts have been changed fairly recently - using cheapest of the cheap so I will have to redo some of it again, I already changed a power window motor from a made in China junk to an OEM used.
Why not just patch the stainless line with a section of braided tubing? I had to do that on my 2002 and it was not that difficult. Rear heat is nice and helps to keep the interior heat even....otherwise the front never keeps up in the winter.
Van has a divider in it and is just going to be used for cargo in the back. I'm not even sure what's leaking, it just seeps enough to make a little wet spot on the ground, could be the hard line is corroded. If I plumb it out I don't have to worry about the salt eating it up.
I've been running a 2002 extended with only front heat and never was uncomfortable. In fact if anything I got too much heat out of it. And it has a hole right in the roof, the state put a vent in that one and it rusted out in front of it, interior condensation was never an issue.
I had the same problem with my 2001, 2500, 5.7. It has rear heat option, it got the plumbing that goes down under to the underside on the passenger side and then over to the driver's side at about mid cargo area.
Two heater pipes and one ac pipe was sealed off underside the van, it looked factory. The lines were never plumbed up into the cargo area and there is no sign there ever was a heater installed in the cargo area.
The two heater pipes were corroded badly at the very end so they leaked, I cut them a couple inches and sealed them again. That seemed to have fixed the problem at first. I could not see any leaks after that but I could still smell like vaporized coolant around the van with the engine running.
I found it very difficult to get to the rear heater lines from the engine bay. Seems like it's not exactly the same on my 2001 as it looks on the 2013 model from the picture mountainmanjoe posted.
I got to the rear heater lines from the passenger side front wheelhouse, I removed the right front wheel and the rubber dust shield at the A-arm and from there I could access the lines and cut the two rear heater lines right after the T- connections and plumbed them together with a piece of rubber hose.
Haven´t driven it very much after this but the problem seems to be solved.
I had my doghouse off to change the EVAP solenoid and I didn't see any obvious access to them from there, so it sounds like your route might be the easiest access.
The answer to this turns out to be ridiculously simple. Rear heat vans, molded hose comes off intake behind alternator, drops down towards heater, connects to one line, other line has a hose that connects to the plastic fitting on the heater.
No rear heat? Different molded hose, with an upturn on the heater side, connects from intake directly to port on the heater box. Can buy a new one for about ten bucks.
Hardest parts of the job look to be the alternator has to come out for access and the fitting on the heater is plastic, it's going to need great care to pull that old hose off.
December 20th, 2018, 11:08 AM
Diagram of heater hoses and lines?
