Tuesday, February 15, 2011


We are once again in "the west" after a too-long absence. This morning finds us at a quiet picnic area on a remote stretch of US-190, a few miles east of San Saba, Texas (map). This is actually the first picnic area we came across since leaving Killeen, and even though we had planned to be another 50 miles west, in Brady, when we stopped, this spot was very appealing and we made it an early day.

That was just as well, because it was in the 80s when we stopped, and perfect conditions for me to wrap up the repairs that I started on Sunday. My first project then was to replace the wiper motor, which was actually a slam-dunk, if a bit tedious. The new motor went right in, although I had to add some washers since I had enlarged the mounting holes for the interim motor, and this direct replacement had smaller bolts.

The replacement hydronic pump had actually arrived Friday afternoon, so my next challenge was to get that in place. Mid-project we had to borrow our friends' car and run out to Wal-Mart for gasket sealer, so we also picked up a full load of groceries, two gallons of coolant, and a pair of shorter wiper blades. Ironically we had to go another mile to Auto Zone anyway, since Wal-Mart did not have the right stuff for the pump gaskets.

Getting the pump into position was a challenge, as it involved lying on my back under the rear bumper, holding the pump in place with one hand, and trying to position the mating flanges, with tacky gasket sealer already applied, with the other. A third hand would have been useful to align the bolts, but there was just no way to get anyone else in there. In hindsight, I should have removed the hoses from the flanges and assembled the flanges to the pump on the bench, but I was worried the hoses were getting brittle and I did not want to introduce another failure.

I topped up the expansion tank with the extra coolant (actually one gallon of straight coolant and one distilled water), left the pressure cap loose, and opened the downstream valve in the hopes that the two foot slug of air in the lines would bubble its way out the downstream end, which goes through the boiler. The pump is at the lowest point in the system for exactly this reason. I left the upstream valve closed until we could drive a while to jiggle everything around, so that no air would work its way upstream.

We took our friends and their whole family out to dinner Sunday evening as another thank-you. It was our first ever visit to a Five Guys Burgers and Fries (their choice). Very tasty, but not exactly diet-friendly. We spent another couple hours with them yesterday morning, after the kids went off to school, before packing up the bus and getting ready to head out. It was a great visit, and we really appreciate them watching our pets and taking care of Odyssey while we were gone.

We were on the road by noon, with our first stop at the Wal-Mart in Lampasas about an hour later. I had to return the 26" Rain-X wiper blades I bought on Sunday as they did not fit the mounts, even though the last 28" blades I had bought were also Rain-X models. I ended up buying 24" Anco blades, the longest Anco which fits the mount (the 26" and 28" models lack the necessary hole). It turns out the 24" ones provide plenty of coverage with our overlapping wipe pattern, and shaving a full 8" of blade drag off the load on the new motor should help a great deal. There was nothing wrong with the old wiper blades, but I felt the massive 28" of blade drag, times two wipers, contributed to the early demise of the original motor a year ago.

As long as we were stopped, I took the opportunity to open the other hydronic valve. I reasoned that most of the air should have jiggled its way up past the boiler after the first hour of driving, and any air still trapped between the upstream valve and the pump would have to migrate back through the upstream part of the system anyway. This would give us the rest of the day's drive to move that air to the top of the system, or at least string it out into a long series of much smaller bubbles, unlikely to damage the pump.

We arrived here at the picnic area before 3pm and I got to work reconnecting power to the pump and testing the circulating system. We did hear some gurgling as entrained air moved through the system, but it sounded mostly minor. After a few minutes of holding our breath we decided to fire up the boiler, even though it was in the 80s here, to make sure the entire system was operating. We had heat coming out of the fan units in just a few minutes, so it looks like we were successful, although I am still nervous about possible air in the system.

After wrapping up the hydronic pump and installing the new wiper blades, I turned my attention to the fresh water pump. When we arrived at the bus after returning from Virginia, we noticed the pump was running constantly -- never a good thing. Normally when we leave the bus for a week we turn the pump off (although it is almost never off any other time), but this time we left it on in case the boys who were watching the pets needed it for anything.

The temperature in Killeen dropped into the low teens a couple nights while we were gone, and, with no Webasto running to keep the bays warm, I expect that we had some freezing in the plumbing. Most of our plumbing is PEX, which is tolerant of freezing, but it is possible that some water actually froze in the pump head itself. In any case, even after re-priming the pump we noticed it was ingesting a lot of air, and it would sometimes continue to run after closing the tap.

So I ended up emptying the top of the bay and pulling the pump head off. I had just rebuilt most of this head within the last year, as the internal check-valve assembly had finally worn out after six years of full-time operation. I neglected to change the diaphragm, as getting the swash plate off the shaft is a lot of work, and this time I found the diaphragm to be seeping slightly. After changing the diaphragm and swash plate, things are much better, but we are still getting some air and pump run-on. I suspect that whatever did the pump in has also worn out the check valve assembly, even though it is less than a year old. That could have been freeze damage, or it might also have been the pump running continuously for several days without pumping any water. In any case, I am out of spares and so will have to order another rebuild kit for it.

It was past 5pm by the time I got all the projects finished and the tools packed up, just in time to sit outside with a glass of wine and enjoy the developing sunset. This picnic area is at the crest of a hill known as Fivemile Hill, a feature so prominent that it was used by Native Americans for smoke signals. That gave us a wonderful sunset view as well as some twinkling lights in the distance from San Saba after sundown.

In just a few minutes we will continue west, and should end up somewhere near Eldorado tonight. Now that we are in the west, where scenic, dark, peaceful, quiet, and free overnight spots are abundant, we are more relaxed.


  1. I'm pleased to hear that the hydronic pump replacement went well. Out of curiosity, did you identify the failure mechanism on the old pump? My experience with most pumps has been that some kind of damage occurred before the internals were truly "worn out."

    I also noticed what I'm guessing is a spiffy outdoor portable LED ground lamp. I haven't seen one like that. Where did you find it?


    Phil L.

  2. @Phil: I did take the end plate off the old pump to see if I could spot a problem. The impeller looks OK and turns freely, and putting 24v to the pump causes it to spin properly. I also checked the brushes, which were fine with plenty of meat left on them. There is a bit of a gap between the impeller fins and the end plate, and, frankly, I don't know what the spec is for that. So, no, I have not yet determined the failure mode of the pump. I'll be hunting around the MP web site to see if I can find more information, and specifically how to remove the impeller. Worst case, I will bring the whole thing in to Sure Marine next time we are in Seattle and have them look it over; they rebuild these all the time.

    The lamp you see in the photo is actually a $3.50 item from the garden department at Wal-Mart. It has a steel tube and a plastic stake to stick it in the ground. I had a polished stainless soap dispenser pump bottle that I was ready to throw away because the plastic pump inside it had crapped out, and I decided to turn the bottle into a base for the lamp by removing the pump mechanism and securing the steel tube into the bottle with an O-ring. When we park on the grass I can pull the tube out of the bottle and use the plastic stake instead.

  3. Sean,
    This may be the dumbest question of all time so be warned.
    The picture of you sitting in the Infinity Coach chair in front of your bus shows you sporting some shoes I once had. They were the most comfortable shoes ever.
    Would you be so kind as to look inside for a brand name please? I cannot remember where mine came from or the brand name. Somewhere in my travels I lost them and have been seeking a new pair.

    Again, Sorry I missed you Monday. The ACL grand opening with Willie and Tony Bennett was great. Not sure how many chances I would have had to see Mr. Bennett and I did not want to regret not going when I had the chance.

    Love the blog!


  4. @Justin: That's Louise in the photo; I'm behind the camera. It's a fuzzy shot, and she's wearing one of those dumb cell phone headsets, because she was actually on the phone when I snapped this.

    The shoes are Merrells, which she loves. She has chronic plantar fasciitis, and the Merrell brand is one of the few she finds comfortable for all-day use.

  5. Sean -
    Thanks for the info. A creative re-use of a stainless bottle! I'm also pleased that, through Justin, I'm now assured that I'm not the only one who notices the details in your pictures...

  6. Sean,
    I should have blown the photo up by clicking on it. I am SO embarrassed. Please tell Louise I am an idiot and I meant no harm.

    Thank you for the name of the shoes. Those are the ones. A Google search found me a store that carries them in Temple, TX.
    Be Safe,


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