How to replace RV Tanks, Valves and Sensors

Is any of your RV tanks leaking or has broken valve or sensor? Learn how to replace them without ruining your vacations….

The bottom line is - although it is always easier (and "cleaner") to bring your RV to the dealer,  it is not always possible.

So sometimes the the best option is to roll-up the sleeves and get "dirty"....

How to replace RV holding tank valve?

Step by step procedure

  1. Flush out and clean both grey and black water tanks prior to starting the replacement
  2. Identify which valve is leaking then remove the 4 small bolts that are found on the outer flanges of the valve
  3. Make sure you have a container below the valve to catch any drips when the bolts are removed
  4. The valve is found in the middle of the two flanges so separate the valve sections such that the “T” handle drops out of the center along with the valve
  5. Make sure to remove the rubber gaskets that come with the valve; there should be one on each flange
  6. Lightly coat each seal on the adapters with plumber’s grease or some silicone lubrication
  7. Clean out the two flanges before adding in the new valve then also lubricate them with plumber’s grease
  8. Reassemble the flanges with the new valve and reinsert onto the holding tank. 
  9. Replace the 4 bolts to fix the valve in place and make sure not to over-tighten
  10. Run water through both grey and black water tanks to ensure that there are no leaks

... let's walk through the replacement process ....

RV Fuel Tank Replacement

  1. Start off with the manual for your specific RV so you are familiar with which tools are needed and which hoses to remove first.
  2. It is best to do the replacement after the tank is fully out of fuel so it doesn’t weigh too much at removal. If necessary use a siphoning kit to remove some of the excess fuel
  3. Depending on the amount of clearance beneath your vehicle make sure that the RV is raised and secured with wheel blocks, and jack stands.
  4. Generally you should see a fuel fill hose and a smaller overflow hose side by side. Untighten the clamps that tie the hoses down and remove the hoses
  5. Make sure you have a catch bucket below the fuel pump in case of leakage when hoses are removed
  6. Plug up the holes left by removing the hoses so as to keep the fuel fumes inside the tank while you work underneath the RV
  7. Check your repair manual for the locations of the straps that hold your tank in place. Spray the bolts of the straps with some penetrating oil to soften them up then wait a few minutes
  8. Remove the bolts that hold the straps in place then release the straps from the RV tank. Make sure you have a jack stand or two under the tank to prevent it from dropping too quickly and ripping out the other wires still connected.
  9. Once the tank is loosened drop it onto the jack stand enough to give you clearance to the fuel and electrical connections. Proceed to disengage the electrical connections and fuel lines using tools specific to your RV’s fuel lines
  10. Remove the vent hose then lower the fuel tank of the way
  11. Once your tank is removed bring in the new RV tank underneath the vehicle then use jacks to lift it enough so it is close to the connections that need re-securing
  12. Connect the fuel lines and electrical connection to the tank
  13. Lift the tank the rest of the way up and reattach the belt straps
  14. Reconnect the fuel hose and overflow hose then secure them in place

  RV tank sensors replacement

Prevention is always the best approach, so first see what is causing the sensors to stop working properly!

  1. Start of by emptying and flushing out both the grey and black water tanks. This will prevent spillage when the old sensors are removed
  2. Use a wrench to remove the 2 external nuts that connect the sensors to the holding tank. Each water tank will have 1 nut connecting the sensor down
  3. Carefully remove the electrical wire that transmits the sensor’s readings
  4. What you are left with is just the end of the sensor probe sticking out from the outside of the tank
  5. Do not just use the wrench or pliers to rip out the sensor otherwise you will damage the tank because it is difficult to dislodge the sensor
  6. Instead use an 3/8 inch open end wrench or one that is big enough to cover the sensor probe but without leaving too much space
  7. Then place a regular washer over the wrench and secure both with a nut. You should have a layered view of the sensor probe at the bottom followed by the wrench then the washer and the nut on top of it all
  8. Using a 3/8 inch drive socket start tightening down on the sensor and as you tighten it eventually just pulls out the sensor without damaging the sides of the tank
  9. Once the sensor is removed, drop in to the hole the new sensor probe then use the nuts to tighten and finish off by reconnecting the electrical wire for transmission


  1. An alternate method to not dealing with the removal of the old sensor so as to avoid damaging the tanks is to drill a new 3/8 inch hole next to the old sensor
  2. Then you place the new sensor in that hole tighten the nut and transfer the electrical wire from the old sensor to the new one

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