markopolo-ClassB
Senior Member
If you have an older propane tank it might have an Auto Stop valve. The Auto Stop is no longer made. It uses a piston rather than a float to prevent overfilling the propane tank. The vent valve must be fully opened in order to fill the tank. If the vent valve is only partially open then the overfill protection will kick in and prevent you from filling the tank.
Notes: The reset button (to activate piston) cannot be pressed down unless the Vent valve is open.
It is functional but propane filling attendants might not know how it works.
Auto Stop valve filling instructions copied from the label:
This tank is equipped with an Auto Stop valve.
80% Automatic Stop Fill Valve Operation Instruction:
1. Make sure the vent is closed.
2. Connect hose to acme thread.
3. Turn on pump.
4. Open vent to start filling.
CAUTION! If filling rate is slow, or is not filling, press the opposite end of vent stem to activate piston. Filling should start immediately.
5. Vapor will discharge similar to standard vent valve.
6. When liquid appears, filling stops. Close vent stem.
7. Stop pump.
8. Place acme cap on valve
Auto Stop Corp
Lynwood, CA
You can purchase a Fill valve and a separate Bleeder valve to replace the Auto Stop valve. This will make the fill system the same as modern RV's. I think I have found high quality replacements. Cost is $30 or so for the parts. I will post the details once I speak to the company to confirm.
Notes: The reset button (to activate piston) cannot be pressed down unless the Vent valve is open.
It is functional but propane filling attendants might not know how it works.
Auto Stop valve filling instructions copied from the label:
This tank is equipped with an Auto Stop valve.
80% Automatic Stop Fill Valve Operation Instruction:
1. Make sure the vent is closed.
2. Connect hose to acme thread.
3. Turn on pump.
4. Open vent to start filling.
CAUTION! If filling rate is slow, or is not filling, press the opposite end of vent stem to activate piston. Filling should start immediately.
5. Vapor will discharge similar to standard vent valve.
6. When liquid appears, filling stops. Close vent stem.
7. Stop pump.
8. Place acme cap on valve
Auto Stop Corp
Lynwood, CA
You can purchase a Fill valve and a separate Bleeder valve to replace the Auto Stop valve. This will make the fill system the same as modern RV's. I think I have found high quality replacements. Cost is $30 or so for the parts. I will post the details once I speak to the company to confirm.