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Technical Projects 2006


Disclaimer:  The stories you read here are what I did personally.  You should not assume that you can, or should, do anything that I've done.  Don't assume they are safe, and don't assume they will work for you.  Do more research, and make your own choices.  I will not be responsible for your outcomes!


February 25, 2006


Installing an "Anode Rod" in our RV Hot Water Heater

Does your RV hot water heater have an anode rod?  What's an anode rod you ask? 

An anode rod is an aluminum or magnesium rod that reduces corrosion of the tank.  It does this by corroding itself so the tank itself doesn't.  For a scientific explanation do a Google search.

We have an Atwood brand RV water heater, which doesn't come with an anode rod.  If you have the Suburban brand it comes with one, but you should inspect it each year to see if it needs replacement.  They cost between $10 and $25.  The hole where the anode rod goes is the same one used if you installed an electric heating element kit (like a Hot Rod or Lightning Rodd), so you can't use both at the same time.

Nylon Plug and Anode Rod with Drain Petcock

It was literally a 10 minute job to install the Anode rod in our tank.  So it's a mystery why I purchased one in June, and I've been procrastinating to install it ever since.

  1. Turn off the heater.  To avoid injury, wait until it cools, or turn on a hot water tap for a few minutes.

  2. Turn off the water (shore supply) and turn off the water pump.

  3. Release pressure from the tank by opening the pressure relief valve (or just opening up a hot water tap)

  4. Remove the nylon plug from the tank.  The Anode will go into this hole.  Clean the threads with a cloth if necessary.

  5. Put some Teflon tape on the threads, and screw it in.  Use a wrench, but don't get carried away and over tighten!

  6. Fill, and bleed off the air by opening a hot water tap.

  7. Turn on, check operation, and check for leaks.


Anode Rod Installed


You can buy these anode rods (and the electric elements too) at most RV parts stores, and many places on the internet.  PPL Motorhomes in Houston, TX seems to have a good supply of parts and good prices.  We've ordered a few things from them online.  Here's a link:


Project Update


Click this link to read about Water Pressure Regulators

Just like an insurance policy, this is something no RVer should be without!



March 2006 (Update, Feb 2007 and July 2007)


Auto Park Brake Repair


We have a 1996 Southwind on a 1995 P30 chassis.  If you have a large motorhome on a P30 Chevrolet Chassis (or the P32 and most Workhorse Chassis) then you have the great pleasure of owning an "Auto Park" park brake system.  It seems that these motorhomes over 34 feet are too heavy for a parking brake pawl in the tranny.  So the solution is an automatic parking brake that is applied when you shift into park.  There are variations, but it works like this:


Visualize a drum brake on the tailshaft of your transmission.  Before you start the engine, this brake is engaged and held by spring pressure so the driveshaft can't turn.  You start the engine, and shift out of PARK into any other gear.  At that instant, a switch in the shift linkage is engaged, causing 12v to be applied to a hydraulic pump.  This pump applies pressure to the brake shoes, and moves them back from the drum, now the vehicle can move.


When you put the RV into park, the opposite happens.  12v is removed from the hydraulic pump, pressure is released, and spring pressure pushes the shoes against the drum. 


Sounds like a good system, and when it works it's OK, but many systems fail at least once.  One common failure is the switch at the base of the steering column.  It wears out, and when it's hot from driving all day (and the engine heat) it won't engage in Reverse, and you can't back up!  This was my issue.  I installed a switch on the dash so when it failed I could throw the switch and disengage the park brake so we could back up.  It was a useful work-around, but a safety concern because if you forgot the switch was flipped and put it in park with the engine running you had no brake!


Other ways it can fail include; losing power, causing the brake to be applied in motion, leaky actuator valve, normal wear of pads requiring adjustment and service, etc.


The big problem is, you can't seem to find anyone who understands this system and is capable of fixing it.  We looked around and talked to several shops.  We finally found one that sounded good.  Campbell RV Service in Sarasota FL.  They diagnosed and repaired our Auto Park.  So thumbs up to them!  They are an authorized Workhorse service center, so if you have a P30 or the newer Workhorse, and need the Auto Park fixed, they can do it.  (However, I also had a negative experience with them regarding dash wiring and the AC system, so they're good at some things and not others).


Here are two photos of the Auto Park fix.  I didn't get one of the whole thing installed, but have one of the assembly, and another of the place where it goes.
































Looking forward, inside the driver side wheel well.  Interior sheet metal panel has been removed.  Arrow points to location where Auto Park lever, linkage, and switch assembly was buried (thank you design engineers).



Here's the whole lever, linkage, and switch assembly.  The green circle shows the replacement switch.  Note that it IS adjustable, so if you're having a problem getting it to release in reverse (or similar issue) you might try adjusting it first before replacement.


Update Feb 2007  I found a Yahoo Group that is dedicated to the P-30 chassis (and variations).  They have a ton of information about the AutoPark and other chassis systems.  Visit them at


Update July 2007  We were stranded again by our Auto Park brake.  This time it was in Las Vegas in 110+ degree weather, but at least we were in a RV park instead of on the side of the road.  Through the Yahoo group above, and an AutoPark expert on (user name "oldusedbear") I was able to troubleshoot and fix the system myself.  Very thankful for that, since it would otherwise have required a tow to a RV shop that may have been clueless and a likely to $300+ repair bill.  I fixed it myself for about $70.  I could have done it for around $45, but didn't want to wait longer for the part by mail-order.


The problem was the pressure switch, lovingly called the "Rotten Green Switch" or RGS by us P-30 owners because it's green, and it's a common reason for failure of the system.  What it's supposed to do is allow the pump to run until a set pressure is reached (releasing the park brake) then turn the pump off as long as the pressure is maintained.  When it fails it usually fails internally first, and causes the pump to run constantly.  This builds up pressure and might cause a leak, often in the switch itself, or burn out the pump.  Replacing the switch wasn't hard once I knew where to find it.  I expect that it took about 45 minutes total including the troubleshooting tests to verify the bad switch.  Make that 3 or 4 hours if you include internet research, reading tech data, and calling around looking for the part.. 



April 23, 2006


Replacing Sewer Waste (Dump) Valves  Updated November, 2007


Oh the joys of do-it-yourself RV repair!  One item that ranks high on the list of dreaded tasks is replacing the valves for the black and gray tanks.  Ours have always been tight and hard to open and close.  Finally the black valve jammed one day and wouldn't close fully.  After several cycles of open/close I did get it to close, but it leaked slightly -- a couple drips an hour, an ounce a day or so.  Can't have that!


I've never replaced them before, but it looked simple enough -- and it is.  You can purchase new seals alone, but the whole valve assembly is about $15.00 for the 3 inch and $11.00 for the 1 1/2 inch so why mess with seals alone!?  I dumped the tanks, flushed out the black tank with fresh water, and let them drain until they stopped dripping.  Removed the 4 bolts from each valve and they just fell off.  Not counting the trip to the dump station it took about an hour. 


Photos below show it all.  The valves consist of a thin plastic blade that slides between rubber seals.  Four bolts hold the whole thing together.  Also see update below.



The old valves

Update on Dump Valves - November 2007.  You know how dump valves will start to bind, get tight, hard to pull out and push back in?  The cure for that is easy.  Drill a small hole, plug it with a screw, and use this hole to shoot some silicon lube into from time to time.  One caution, make sure the screw is back in before you dump!   Yes, I did learn that the hard way!  See photos below.




July 2006


Jotto Desk


I heard about these laptop holders, and remember seeing them in police cars and commercial vehicles.  Saw several different setups online and selected the Jotto as likely the most versatile, stable, and well built.  Ordered the generic Motorhome model (web site was a little confusing in that area, but called and got it right on the phone).  Got the one with 2 support legs, a must if you're going to use it in motion (and why have it otherwise!?).  Also got the screen holder that keeps the screen up and in position, another "must have". 


I swing it over to the passenger side when I'm over there, and then to the drivers side when I'm behind the wheel.  Chris doesn't like to read while riding (gets motion sick) and HATES to navigate, so she likes it too :-) 


It was easy to install.  Self tapping screws and a drill with a socket adapter.  Here's a link to their web site.



July 2006


Fuel Pump Replacement


Our fuel pump failed on a hot July day in Northern California.  Click here to read all about it in our blog.



Continue to 2007 Tech and Projects




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