Repairing PVC Pipe under a trailer can seem a daunting task, it can be if you dont like to get dirty but this could save you lots of money from a contractor who will charge tons to repair it. I worked as an electrician for 13 years and all conduit either irrigation or electrical serves one purpose, to either hold or have something pass through it. The same applies with anything to do with plumbing under your trailer or mobile Home.
If the leak on your plumbing is not inside the house meaning you cant see water under the sinks in the kitchen, bathroom or anywhere else but your experiencing low water flow it may be a leak under neath the house. Most trailers sit on blocks with an access door for you to go in. Take a flashlight and look for pools of water underneath, you may see water dripping from the insulation as the pipes are normally not exposed to prevent freezing and to insulate. Locate the leak first and check the size of the conduit or irrigation pipe that has sprung the leak.
Once you have located the leak the next step is to get a saw preferably a hacksaw and cut off the piece that has broken. Oh and make sure the water is off, this is a must. Also you will need two couplings PVC to fit either end of the pipe. Once the pipe has been cut its time to move to your next step
Measure the space between the pieces you have just cut and cut a new piece of pipe at that measurement, PVC is flexible so if your off a little its ok, maybe an inch at the most. Attach the new couplings on either end of the new pipe using PVC cement and let sit for 10 minutes. Finally fit the finished piece with the two couplings attached into the two pieces of pipe exposed which you cut out. Add additional glue around the coupling edge of the pipes where it connects to the PVC and let sit for about an hour. Turn back on the water and check for pressure, this should fix the problem. It may also save you upwards of 300 bucks for a contractor who will overcharge, remember its not the man that does the work that overcharges its the business itself, these are things you can do yourself around the house easily. The same applies to under the sink leaks, add some PVC Glue to the hole or do the same cutting out I mentioned previously and this will do the trick. Good Luck Dave