Monday, August 24, 2009

Unenchanted Forest

We are parked just off a dirt road, Forest 518, at the junction of two high-clearance roads, in the Coconino National Forest (map), just a few miles west of Flagstaff, Arizona.

We did not make it far yesterday. In a sort of comedy of errors, I carefully observed both new tires during my pre-drive walk-around, even thumping them with a hammer (yes, I know -- not a reliable indicator of proper inflation). No sooner had we gotten onto the Interstate, though, when the tire pressure monitor system reported the right tag to be 40+ psi low, at around 70 psi. We had noticed a couple psi drop while driving the day before, and were mildly concerned the tire might have a slow leak; this confirmed it.

We pulled off in Seligman to take care of it. I ended up parking in a lot by one of the kitschy Route-66 joints, hauled out the air hose, and plugged it in to our on-board Hitachi electric compressor. Usually, we have the compressor set on 85 psi or so, which is all we need to keep the suspension up, operate the air door, and flush the toilet. To fill a tire, I need to crank the regulator back up to the compressor's maximum output of 135 psi.

As I was turning the knob on the regulator, it popped off in my hand, hitting me in the chest and landing on the ground. It turns out the plastic housing had become brittle, and the increased tension on the regulator spring caused the top of the housing to break clean off, sending the knob flying under spring pressure. With no regulator spring tension, we could not get any air out of the compressor, even though there was 135 psi in the tanks.

By holding the spring in with the broken knob by hand, we were able to get the tire back up to 85 psi or so (it only requires 90 for the load on that wheel), and we then limped along to the Chevron truck stop at the east end of town, where they had an air hose that could finish the job (most auto-only gas stations have their air systems set too low to fill a heavy duty tire). It turned out that the leak is in the stem valve, and I've stopped it temporarily with a stout metal valve stem cap with a rubber insert; as soon as I can, I will replace the valve core.

Knowing that the very next thing we'd have to do is fix the compressor -- so many things require air, and we'd have to start up the main engine every hour or so without the electric compressor available -- we decided to stop in Flagstaff, in case we needed a store or a shop. As Flagstaff proper is RV-unfriendly, we ended up here, in the National Forest, at basically the first place we could park Odyssey for the night. Under normal circumstances, we would have driven further into the forest in search of a more scenic and relaxing spot, but I wanted the easiest access to town if I needed to run in on the scooter for something.

Now, it happens that I had an air pressure regulator lying around, almost identical to the one on the compressor, except it is a 5-100psi unit instead of 5-135. Unfortunately, it was broken -- it had been part of the air toilet installation (the toilet requires the air pressure to be regulated at precisely 60 psi), and it had failed only a about a year after we hit the road. Not wanting to fiddle with the regulator, we simply stopped at Grainger and picked up a (slightly different) new one for around $12. I set the old one aside because I figured it just needed a cleaning, or a new diaphragm.

So after we got settled in here, I pulled out the spare, disassembled it, and cleaned and lubed it with WD-40. After fiddling with it for a few minutes, I finally got it to stop leaking, then set to disassemblng the compressor to swap regulators. After several unkind thoughts about Hitachi's design engineers (the thing seems to have been optimized for appearance over maintenance, unforgiveable on what amounts to a contractor tool), I managed to get the spare regulator in place, and all is working again.

There are two problems with this regulator. One is that it only goes to 100 psi -- fine for our daily use, but it means we can't get our tires above that pressure if needed; probably not a big factor, since 100 psi is enough to get us to a proper shop, and we can use the engine-driven compressor to get up to 120 psi in a pinch. The other is that it is just enough different from the stock item that it will not fit into the cutout on the compressor's control panel.

For the time being, I have things jury-rigged around the front panel. Even if I buy a 135 psi regulator, though, I think it will have the same problem unless I order the exact replacement form Hitachi for double the price. I'll probably end up just enlarging the cutout on the panel, in which case we might as well just use this regulator until we find some reason to replace it.

So, not really needing anything from Flagstaff, we will head back onto the Interstate today. The closest Grainger, which is really the quickest place to get a regulator, turns out to be in Albuquerque anyway. We'll probably make a quick stop at the Wal-Mart here though, to pick up a few grocery items and a valve core remover, since I can't find the one I know I have someplace.

For anyone following along with the saga of my computer, I was able to identify a number of corrupted DLL's using Microsoft's WinDiff utility, and I can now boot into safe mode after replacing those DLLs. Still can't get the full monty to run, but I am making progress. It is now looking to me like the hard disk itself is failing, although many CHKDSK passes have found no problems. I think I need to get a better disk checking utility.

Tonight we should be somewhere in the vicinity of Gallup, New Mexico, barring any further tire issues.


  1. hi,

    i have an air doubler (air pressure multiplier) that i bought that is awesome. they put them in the newer high end coaches now as well. mine is not hard plumbed in, but loose. it takes the incoming air pressure and doubles it using a small piston. very cool. they are commercial grade and about 250 bucks, but well worth it. i can air my 11r24.5 tires up to any pressure i want from either the electric or coach compressor.

    here is a picture of it. you can probably find it cheaper by shopping. every bus guy ought ot have one in my opinion. most of my newell buddies have one and love it.

    i will email you a link to it.


  2. The best disk check utility is SpinRite

    Problem is its purchase price is about the price of a new drive. :(


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