NEED HELP REPLACING WATER LINES

Most RV's have hot and cold water low point drain valves used in draining all water from the lines. The valves are usually located behind a panel near the bathroom or elsewhere. These valves must be completely closed when running the water pump to pressurize the system and pump water to the faucets and toilet. There are small diameter tubes that water drains from underneath the RV. All tubing must be connected to faucets etc. without any leaks for the electric pump to pump water and to shut off automagically when faucets are closed. All faucets must shut off without leaks. You may need to replace the electric water pump with a same gpm capacity pump. You may want to install a more powerful pump for stronger shower spray. You may need to install an Intellitec device when installing a higher amp pump. Low water pressure when hooked to city water supply may be due to a faulty one way valve assembly on outside of your RV. Check any filters on faucets for build up of lime deposits. There may be a clogged flow restrictor in your shower head and toilet supply due to lime deposits. You might get help with RV plumbing from a local RV supply/repair place with knowledgeable people. BTW all electrical connections and remote water pump switches must be good and your 12 volt house battery must good and fully charged for pump, furnace and AC thermostat and appliance controls to operate properly. Getting an old rig's innards working properly can be a challenge unless you are experienced with RV electrical, propane, and plumbing systems. Good Luck! There are some good You Tube videos on RV repairs and upgrades as well as maintenance.