Tech Tips

Holding Tanks 101

This is probably old news for the RVers with a few years under their belts. But, I thought it might help someone new to RVing.

The first thing to remember is the holding tanks are just that, "Holding Tanks" and not a Septic System.


  • Use plenty of water when you flush.
  • Let the tanks fill to at least 3/4's full before dumping.
  • Use a sewer donut with your sewer hose connector.
  • Install an "anti back flow" valve on you black tank inlet.
  • Install a clear plastic connector so you can see if the tank water is running clear during the cleaning cycle.
  • Dump the Black Tank 1st & Gray Tank 2nd.
  • Replace you sewer hose every 2 years or so. UV rots the plastic and you will have leaks.
  • Use T paper approved for septic systems.
  • Use disposable latex gloves when dumping the tanks and handling the sewer hose.


  • Don't leave the dump valves open or you just might end up with poo poo pyramid.
  • Don't dump anything other than water down the kitchen sink. Why? The Gray Tank does not have a power rinser and the outlet pipe is only about 1-1/4" compared to the 3" black tank drain line. This allows food particles to remain in the tank.
  • Restrict the use of chlorine bleach. It's bad for the seals and not really good for a septic system.
  • Don't mix rinse tank hoses with fresh water hoses.

Dump/Rinse Procedure

  1. Put on a set of gloves if you need to handle the hose.
  2. Check you hose connections.
  3. Pull the dump hand of the black tank. Let the tank empty BEFORE you turn the rinser.
  4. Hook up you rinser hose and turn on the water. Let the rinser run for a couple minutes.
  5. Close the black tank valve and let the rinser continue to run. Go inside and fill the toilet bowl with water and dump it. Do this 3 or more times to fill the black tank to the full mark.
  6. Dump the black tank again.
  7. Repeat step 5 and 6 one more time. You should see clear water coming from the black tank. If not repeat step 5 and 6 until the water runs clear.
  8. Turn off the rinser and close the black tank valve.
  9. Open the gray tank valve and let it drain.
  10. Close the gray tank valve, replace the cap, rinse your hose and let it drain before placing it in storage.
  11. Dispose of your gloves and wash your hands.

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The GEO Method

Here is a link to the GEO Method homepage.

Now that we have gone through "Holding Tanks 101" then why do I need the GEO Method and just what is the GEO Method?

The GEO method has been around for a long time. I have read that it was used as early as 1988. The GEO Method is a process of using 2 commonly available cleaners to "Super Clean" the holding tanks. The gentleman that is credited with being the originator uses Chlorine Bleach on occasion. I personally do not recommend this unless necessary.


  • 1 box of Dish Washer compound. The cheapest you can find. I use Lemon scented.
  • 1 Container of Calgon Water Softener.
    Note - Calgon also come in a lquid.
  • I have bought both products at Wal Mart


  1. Just before you get ready to take a trip empty your tanks.
  2. Fill each tank at least 1/3 full of fresh water.
  3. Mix about 2 cups of Dish Washer compound and 2 cups of Calgon Water Softener powder in a bucket to warm water and dump in each tank. Add some extra warm water to the gray water tank to make sure you have all solution in the tank.
  4. Now head out to the RV park. The longer the trip the better it works.
  5. When you arrive at the RV park and are set up dump your tanks. You will be surprised what you have washed out.

How often you need to do this? I only use this process about 3 or 4 times a year as I fulltime and dump my tanks a couple times a week.

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Reset WCC Park Brake Circuit

This information was posted by "Flytyer" on

Today (12/28/2007) while in South Georgia, I had the same problem (can't shift out of park). A call to Roadside Service and I was transfered to OEM Tech Service, I was talked thru a corrective action......which follows:

  1. Remove the key from the ignition switch.
  2. Reinsert the key, turn to the ACC position
  3. Press the brake pedal and pull the gear selector lever into neutral.
  4. Start the engine.

This resets the circuit that controls the PARK BRAKE lock circuit. The tech suggested a check by a WH Service Center to be sure.

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Fuel Addatives

Many of us use or have tried any number of fuel additives hoping for some sort of increase in mileage. But, I have yet to see any increase in mileage on additives I have tried and I have tried more that I care to admit to.

The best way to find out just what you are paying for is to pull the MSDS (Material Safety Data Sheet) and see what is in the product.


  • Super Tech-Fuel Injector Cleaner (Wal Mart)
    • Kerosene (95% or more)
    • Naphtha (2% maybe)
    • Proprietary chemical (less than 1%)
    • $4 - 12 oz
    • Wal Mart MSDS
  • Techron Fuel Injection Cleaner
    • Naphtha - 44% wt/wt
    • 1,2,4-trimethylbenzene - 14% wt/wt
    • 01154100-5007P (trade secret)- 6% wt/wt
    • Xylene - 1% wt/wt
    • 1,3,5-trimethylbenzene - .3% wt/wt
    • $6.50 -12 oz treats 12 gallons.
    • Chevron MSDS

The bottom line is, buy your gas from a major brand fuel supplier and that is really all you need.

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Oil Analysis

How many of us have thought about getting your oil analyzed? Well I decided to do 2 tests on my motorhome and toad.

  • 2004 Newmar Mountain Aire
    • Engine - GM 8.1L Vortec
    • Mileage - 25,113
    • Oil - 10W-30 Pennzoil Platinum Full Synthetic
    • Oil Filter - 2 Quart WIX # 51794
    • Mileage on the oil - 5,000
  • 1997 Honda CRV
    • Engine - Honda 2.4L
    • Mileage - 147,483
    • Oil - 10W-30 Super Tech High Mileage
    • Oil Filter - Super Tech
    • Mileage on the oil - 5,000 (real mileage closer to 7,000)

I ordered 2 kits from Black Stone Labs website and received them in about 3 days via USPS. These kits are set to you FREE and you pay for the analysis when you submit the oil samples. The standard analysis cost $22.50 and if you have the TBN checked it will cost you an extra $10. I decided to get the TBN done on both samples as I wanted to see what the diiference was. I also wondered if there will be any differnce in the oil analylsis due high mileage versus low milage or the difference in oil types synthetic versus conventional.

My Results

Mountain Aire 8.1L Vortec

The 8.1L showed higher than normal levels of iron and copper. But, they said that high levels of copper are normal in new or low mileage GM engines and not to worry about it.

I use a 2 quart AC Delco or Wix filter and change my oil once a year or at 5,000 miles. I had the TBN checked to see how much of the additive package was left. The report showed the TBN was 3.9 out of 8 or 9 (average). So, I had about 48% of the additive package left. So much for 3k oil changes!

The Silcon (dirt from the air cleaner) level was 12 and the average is 13. So, the 8 layer S&B filter is working as designed.

There was no fuel, antifreeze or water detected.

Honda CRV 2.4L

The Honda has 147,000+ miles and I thought it had about 5,000 miles on the oil. But, I actually had closer to 7, 000 miles on the oil. I also decided to use a Wal Mart Super Tech filter, Super Tech High Mileage oil and a Fram air filter as a test.

The iron and copper levels were below average.

Here is what Blackstone Labs said about air and oil filters.

"No contaminats were found and the air and oil filters (silcon and isolubles) are working well, too."

Draw your own conclusion about Wal Mart and Fram filters.

The TBN number was 2.4 out of 8 or 9. So, the oil got changed asap with another Super Tech Filter and Super Tech High mileage oil.

From the Black Stone Lab web site:

"What is a TBN, and who uses it? In short, a TBN (total base number) measures the amount of active additive left in a sample of oil. The TBN is useful for people who want to extend their oil usage far beyond the normal range.

By comparing the TBN of a used oil to the TBN of the same oil in virgin condition, the user can determine how much reserve additive the oil has left to neutralize acids. The lower the TBN reading, the less active additive the oil has left.

(Note: You only need to send in a sample of virgin oil if you want to know exactly where the TBN of your specific oil starts out. The TBN of most gasoline engine oil starts around 8 or 9. Diesel-use TBNs start around 11 or 12.)"

The kit consist of:

  • Oil sample container.
  • Bag to seal oil sample container for shipping.
  • Padding for the oil sample container.
  • Pre-labeled shipping container.
  • Oil analysis information request sheet.
  • Information sheet about Black Stone Labs oil analysis.
  • Reminder sticker.

Here are some photos of what you get in the kit.

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Fuel Rail Pressure Test

You may wonder why you need to test your fuel rail pressure. Well, a low fuel rail pressure could mean that you might have a bad fuel pump or a more common problem a plugged fuel filter.

Note - You may want to consider installing the OEM-Engineering Fuel Filter Adapter.

To test the fuel rail pressure you will need a Fuel Pressure gauge that will attach to the GM Schrader valve on the fuel rail. The standard fuel rail pressure is 55 psi to 65 psi.

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MAF Cleaning

On my last trip I was running OBD II scan to collect some data. After Steve Brazel analyzed the data file he mentioned that the Long Term Fuel trims were on the high side and that I should look at my fuel rail pressure, clean the MAF sensor and check the O2 sensors.

Update - Although I checked the fuel rail pressure and cleaned the MAF sensor I still had high Long Term Fuel Trims. But, Steve Brazel had me do a static scan that he reviewed, he then recalibrated the MAF and my Long Term Fuel Trim problem were fixed. So, now we have incorporated this static scan in our UltraPower tune.

  • Fuel Rail Pressure - OK 65 PSI
  • MAF Sensor - OK Cleaned
  • 02 Sensor - OK

If your MAF sensor is dirty you may want to check your air filter. To properly clean the MAF sensor you need to remove it from the air intake system. In my case I only needed a screw driver to remove mine. But, if you have a stock Whorkhorse air box you will have remove the back half of the air box to get the MAF sensor out. This would be a good time to change the filter and trash the foam pre-filter (big restriction air when dirty).

You also need some MAF Cleaner, $7 at any good autoparts store. Be aware that Brake Parts Cleaner, Carb Cleaner and the like are not recommended as they can damage the plastic and/or the MAF sensor components.

Once you have the MAF sensor out you just spray the front and back with the MAF cleaner and let it dry.


  • The MAF sensor also holds the IAT (Intake Air Tempreture).
  • The Workhose Part # - W800513 and costs $243.70 But, if you look up the Delphi # 25168491 you will find that this a very common 85mm MAF. I picked one off EBAY for $26.99 plus Tax/S/H.

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Battery Tender

Most of us don't use our RVs on a regular basis. Therefore the chassis battery does not go through the "normal" discharge/charge cycles that the average automobile battery does. So, I decided to add a Battery Tender Plus to keep the battery charged. The Battery Tender has some neat features:

  • 3 charge modes
    • Bulk - Full Charge Power, Constant Current 0 - 80%
    • Absorption - High Voltage, Decreasing Current 75 - 100%
    • Storage - Low voltage, Minimal Current 100 - 103%
  • Status Indicators
  • Spark proof connections
  • Short Circuit protection
  • Reverse Polarity protection
  • Temperature Compensation
  • Portability
    • 1 Permanent connection - fused
    • 1 Portable connection - fused
  • 10 Year Warranty

I picked mine up off Ebay for $39 delivered to my door. I also decided to pick up some mounting bolts for the battery. This allows you to attach the Battery Tender Plus cables and not have disconnect the battery cables. I got some real nice brass ones at Autozone for $9. You can get some cheaper non-brass ones at Wal Mart for $1.88.

I tested the Battery Tender on my John Deere tractor battery. This battery has been setting for at least 3 months. It brought it back to full charge in about 16 hours. This is just about what the instructions sais t would take. The Green light flashed at the 80% mark and stayed steady Green when fully charged.

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