Chinook RV Forum

Lake Roberts and Purgatory Chasm
Page 1 of 1

Author:  Rokrover [ July 13th, 2017, 5:16 am ]
Post subject:  Lake Roberts and Purgatory Chasm

We were enticed back to cooler elevations in the Gila National Forest to sample more recreational opportunities in the upper Mimbres Valley. Our destination was Lake Roberts and the Chinook was most capable navigating the narrow, serpentine NM Hwy 15 over the mountains north of Pinos Altos. This route deters the usual “Big Rig” crowd.

Along the way we scrambled up an outcrop with a memorial plaque to Ben Lilly and spectacular views along Cherry Creek. Mr. Lilly is renowned as the last genuine mountain man of the American southwest, partly because he was self reliant and a prolific pillager of wildlife.

Lake Roberts is popular with fishermen and we stayed at Mesa Campground as basecamp for hikes with our puppy. The local Purgatory Chasm, carving its way through austere slickrock, was quite a contrast to the more gentle scenery around the shore of the lake.

Not surprisingly, "Mr. Murphy" infiltrated our rig during the hot drive home and arranged for the cab AC vent to malfunction. Youtube tells me this is a notorious Ford failure caused by a vacuum leak and not so trivial to access for repair. For now this inconvenience is shelved on the TBF (to be fixed) list. Any words of wisdom here from the Chinookistas?

File comment: Scrambling around the Ben Lilly outcrop
MRC_0068.jpg [ 386.99 KiB | Viewed 349 times ]
File comment: Lake Roberts
MRC_0941.jpg [ 344.83 KiB | Viewed 349 times ]
File comment: Slick rock above Purgatory Chasm
N55_0062.jpg [ 487.74 KiB | Viewed 349 times ]

Author:  Blue~Go [ July 13th, 2017, 4:18 pm ]
Post subject:  Re: Lake Roberts and Purgatory Chasm

I always enjoy your trip reports - thanks!

On the vacuum. I did some research on this because I thought I might need to do the job (but so far no need). At any rate, of course there are various vacuum lines that can potentially individually fail or fall off their fittings. BUT, there is one main vacuum canister, and apparently Ford started with this canister, then built a van around it :roll:

You can take the entire dashboard/front apart (um, no), or some people were cutting holes in the sheet metal inside the right front wheelwell (from outside) to access the original canister. But then some people hit on a better way. They simply bought a vacuum canister (at Napa or wherever) and installed it somewhere out of the way (up under the passenger ankle area is one I remember) and then connected that. Lots of people reported success and I don't remember reading it not working for anyone. There was quite a bit of discussion of it on -- they have an Econoline sub forum.

Then last winter I was at a shop that works on a lot of Ford RV's (dropping off a friend for some work) and we got to talking. The vacuum thing came up and they said that's what they do (just use a new canister and route around the original). They work on a lot of classic and restored cars, so they don't seem like slobs.

If the vacuum fails, one thing you'll notice is that your dash HVAC always defaults to defrost position. Or maybe does it only when you pull a hard load (that uses vacuum and maybe there is not enough to go around).

One easy thing you can check (I'm not clear on your symptoms exactly) is to pop that little sort of kidney shaped cover off that is in the center of the dash. Inside there you will see several vacuum lines and the splitter for the various dash HVAC functions. The reason I know about that spot is that's where I tapped into a line for my "no heated vents" valve that I installed under the hood. Somewhere I have a chart of the lines/van "map" of HVAC. What are your symptoms exactly?

Author:  Rokrover [ July 14th, 2017, 2:57 am ]
Post subject:  Re: Lake Roberts and Purgatory Chasm

apparently Ford started with this canister, then built a van around it

How true… I always enjoy your sense of humor, B~G.

Symptoms are no vacuum (telltale hissing sound) to the HVAC control knob and then, as you say, stuck in default defrost mode. Karma after feeling pleased with myself ditching the rooftop AC!

So I jump to the conclusion the vacuum canister (reservoir, pod, accumulator?) failed, as many report on, and decided the bypass solution you advised is best. No way am I about to dismember the dash and firewall chasing down gremlins at my age.

However I will pop the dash cover to be sure the splitter connections are OK before an appointment with my trusted mechanic next week. They also build hotrods and classic cars so have the requisite passion to do good work. This repair could be its own topic if (when) others report the same issue.

P.S. Just thought I’d add this picture at the Lake Roberts campsite showing vents open and jib unfurled to catch the breeze

N55_0051.jpg [ 433.44 KiB | Viewed 323 times ]

Author:  SMan [ July 14th, 2017, 7:23 am ]
Post subject:  Re: Lake Roberts and Purgatory Chasm

Great pictures Ted. Wish I was traveling!

Author:  Blue~Go [ July 15th, 2017, 7:54 am ]
Post subject:  Re: Lake Roberts and Purgatory Chasm

The awning really sets off the sleek roofline :D

Author:  Skillet [ July 17th, 2017, 7:46 am ]
Post subject:  Re: Lake Roberts and Purgatory Chasm

I had that exact same problem when I first got mine. As Blue noted, the work-around is what my Ford truck center did to correct it. They said they could have fixed the issue where it was located but it would be very expensive.

Author:  Rokrover [ July 20th, 2017, 5:15 pm ]
Post subject:  Re: Lake Roberts and Purgatory Chasm

Just picked up our Chinook after repair of the HVAC selection problem mentioned above so I thought I'd close this out here. The tech’s report is:

“Found no vacuum available to HVAC actuator, suspect vacuum line is compromised inside of evaporator case. Installed remote vacuum reservoir, ran new vacuum supply line with check valve as alternate vacuum source for HVAC control”

Parts $62.31, Labor $294.00

The service manager mentioned one customer who insisted on repair by the Ford service manual and the labor cost escalated to over $1,000 owing to parts being buried in the equivalent of a subterranean vault.

So, as we suspected, a common Ford E-350 failure with the bypass workaround being the most practical and economical fix. A good Youtube covering this is:

As I checked out the service manager told me their multi-point inspection showed my license plate light isn’t working. A new bulb wasn’t a quick fix so I deferred this to my home DIY repair list. Sigh, Skillet’s observation “Concourse where there's always a project going on…” is most apt.

Update on light fix: Turns out the white ground wire to the license plate bracket was loose. It was held captive against the fiberglass body by a sheet metal screw. I contrived a more robust connection to the metal bulb plate itself by drilling out one rivet and substituting a machine screw with locknut. Of course the housing rubber gasket is cracked with age allowing ingress of dust and water so this was refreshed with a spritz of Aerospace 303.

Since the HVAC repair is of general interest I end with the keywords to enable a search, rather than start a separate thread.

Keywords: HVAC selection control knob vacuum bypass

Author:  Blue~Go [ July 20th, 2017, 9:30 pm ]
Post subject:  Re: Lake Roberts and Purgatory Chasm

Thanks for coming back with the follow up. That's so helpful (now and in future), plus satisfies a sense of curiosity about how things turned out.

I'm normally biased toward the "OEM" repair, but not on that one!

Page 1 of 1 All times are UTC - 8 hours
Powered by phpBB® Forum Software © phpBB Group