# Plumbing and Tank Repair in San Juan Capistrano > RV plumbing and tank repair covers the pressurized fresh water side, the gravity waste side and the tanks themselves. Work includes PEX and PVC line repair, water pump and accumulator replacement, city water regulator faults, fresh tank cracks, polyethylene black and gray tank repair, termination valves and fouled level sensors, all performed in-shop. **Source:** https://ocrv.life/services/mechanical-systems/plumbing-and-tank-repair **Business:** OCRV Center, 23281 La Palma Ave, Yorba Linda, CA 92887 **Phone:** (949) 799-3387 **Serving:** San Juan Capistrano, Orange County, California, roughly 26 miles from the facility **Typical range:** $285 to $4,500, 1 to 18 hours ## Symptoms - Water pump cycles on for a second or two every few minutes with every tap closed - Fresh tank drains down over a week in storage with no visible puddle - Slow drain and a gurgling toilet, with sewer odor entering through the bathroom - Tank monitor reads full immediately after a complete dump and rinse - Damp cabinet floor or swollen particle board under a sink with no obvious drip - Water heater relief valve discharges every time the coach is on city water - Termination valve weeps into the sewer cap even when the handle is fully closed - Faucet flow drops to a trickle on pump but is strong on city water ## Pressurized Fresh Water and the Pressure Nobody Regulates Two things can pressurize the fresh side of a coach. A 12-volt demand pump such as a Shurflo Revolution draws from the onboard tank and cycles on a pressure switch, typically holding somewhere in the mid forties psi. City water enters through a separate inlet and carries whatever the park decides to deliver, which in Southern California can exceed eighty psi on a good day and considerably more overnight when demand drops. RV plumbing is built for roughly sixty psi. Above that, fittings weep, the toilet valve seat fails, and the water heater relief valve starts discharging. A brass inline regulator on the hose is the cheapest component on the vehicle and the one most owners skip, and we replace far more split fittings caused by unregulated city pressure than by any other single cause. Pump behavior is diagnostic. A pump that short cycles every few seconds with no tap open has either a leak, a failed check valve or a waterlogged accumulator tank. A pump that runs continuously and never builds pressure has lost prime, has a cracked suction line drawing air, or has a worn diaphragm. Neither symptom means the pump is bad, which is what most owners assume before replacing a perfectly serviceable pump. **Typical range:** $285 to $4,500, 1 to 18 hours ## PEX, Crimp Rings and Repairs That Hold Most coaches built in the last twenty five years plumb in PEX with either copper crimp rings or stainless cinch clamps. Both work when done properly with the correct tool and a go/no-go gauge to verify the finished crimp. Neither works when somebody reaches for a pair of pliers, and a marginal crimp does not fail immediately. It weeps a few drops a week into a cabinet floor for a season and then the subfloor is gone. Push-to-connect fittings have their place in a repair, particularly in a location where a crimp tool physically will not fit. They are also the fitting we most often find leaking, because they depend on a clean square cut, full insertion to the depth mark, and an undamaged tube surface. On a vibrating vehicle they want support within a few inches on both sides so the joint is never carrying load. The repair detail that separates a durable job from a callback is line support. PEX expands and contracts with temperature and it will chafe against a bulkhead edge or a screw tip until it opens. Every run we touch gets clipped at proper intervals, grommeted through any pass-through, and routed clear of heat sources and moving parts. ## Fresh Tanks, Waste Tanks and How They Crack Holding tanks are rotationally molded polyethylene, occasionally ABS on older units, and they fail at predictable places: the mounting flanges where straps bear, the fitting bosses where a threaded fitting was overtightened at the factory, and along a seam where a support crossmember bottomed out on a hard hit. A fresh tank that mysteriously empties in storage almost always has a hairline crack at a boss rather than a hole in a wall. Polyethylene cannot be reliably glued. Adhesives do not bond to it in any way that survives flex and temperature cycling, which is why the tube of epoxy from the auto parts store is a two week fix at best. The correct repair is plastic welding with matched polyethylene rod, done after the tank is cleaned, dried and the crack is properly veed out. Where a tank has cracked in more than one place or the material has gone brittle from age and sun exposure, replacement is the honest recommendation. Tank support is the underlying cause worth fixing at the same time. Tanks were designed to be supported across their full floor, and many are hung on two straps and a plywood shelf that has softened from a previous leak. A full black tank weighs a great deal, and hanging that weight on a compromised shelf is how the same tank cracks twice. **Typical range:** $750 to $8,500, 5 to 35 hours ## Termination Valves, Vent Stacks and Level Sensors The gate valve at the termination is a simple blade sliding between two seals, and it fails in two ways. Debris scores the blade and it stops sealing, which announces itself as a slow drip into the sewer cap. Or the handle rod corrodes and seizes, and somebody applies enough force to snap the rod or crack the valve body. Both are cheap parts and awkward access, which is why the labor rather than the part drives the cost. Vent stacks matter more than their price suggests. A blocked roof vent means the tank cannot breathe, so waste drains slowly, the toilet gurgles, and odor pushes back through the trap into the coach. Wasps and mud daubers block them regularly in this climate. A vent cap that has gone brittle and blown off leaves the stack open to rain, which is its own problem. Level sensors are the most complained-about component in any RV. The common design uses three or four probes through the tank wall, and the moment residue bridges a probe to the tank contents the panel reads full forever. Sensor cleaning helps, tank chemistry and a proper flush help more, and external ultrasonic or strip sensors that read through the wall solve it permanently. We fit those regularly on coaches where the owner has simply had enough. - Gate valve replacement with fresh seals rather than a new handle on an old body - Vent stack clearance verified from the roof, not assumed from below - Tank flush wand and rinse system inspection or retrofit - External sensor conversion where internal probes are permanently fouled - Full pressure hold test on the fresh side before release **Typical range:** $200 to $1,500, 1 to 6 hours ## Water Damage, Sudden Discharge and the Coverage Line Insurance treats water damage inside a coach according to how the water arrived. A sudden and accidental discharge, a line that burst, a fitting that let go, a water heater that split, is typically a covered loss. Slow seepage over weeks or months from a weeping fitting is typically excluded as gradual damage or lack of maintenance. The physical damage can look identical when we open the floor. The claim outcome does not. What decides it is evidence, and evidence has a short shelf life. Photographing the failed component in place, retaining the split fitting, documenting the moisture pattern with meter readings and noting the date the owner first noticed water are the things that make a sudden discharge claim stick. We build that file as a matter of course on any water intrusion job, whether or not a claim has been opened yet. Secondary damage is where the real money sits. A twelve dollar elbow that let go behind a wall can produce a delaminated sidewall, a rotted subfloor section, ruined cabinetry and mold remediation. Carriers scrutinize the causation narrative closely on those files precisely because the number is large, so the documentation needs to be right the first time. ## Sanitizing, Winterizing and Southern California Water Orange County water is hard, and hardness shows up in an RV as scale on heating elements, seized faucet cartridges and a toilet valve that will no longer seal. Owners who tow up into the high desert or the Sierra add freeze risk to that. Both problems are managed rather than cured, with an inline filter and softener on the supply and a proper seasonal service on the system. Sanitizing is straightforward and almost nobody does it correctly. The tank, the lines, the water heater and the pump all need to see the solution, which means running every tap until it is present at each fixture, letting it dwell, then flushing thoroughly. A coach that has sat with a partially full fresh tank through a warm summer grows a biofilm that no amount of running clean water will remove. Winterization for California owners is a real question rather than an automatic yes. A coach stored in San Juan Capistrano is unlikely to freeze. The same coach parked at Big Bear over a January weekend absolutely will, and a split fresh line behind a wall is a far more expensive lesson than a bypass valve and a few gallons of RV antifreeze. We blow the lines and treat the traps for owners who travel to elevation. **Typical range:** $250 to $750, 1 to 4 hours ## Process 01. **Pressure hold test** The fresh system is isolated and brought to test pressure with air or water, then watched for a held reading over time. A system that will not hold has a leak whether or not anyone has seen a drop, and the rate of decay tells us how large it is. 02. **Leak localization** Access panels come off and we follow the run with moisture meters, a borescope through cabinet backs and, where necessary, a tracer gas. Chasing a leak by cutting drywall-style openings into a coach is a last resort, not a first move. 03. **Waste system evaluation** Tanks are flushed and inspected with a camera where access allows, vent stacks are cleared and verified from the roof, termination valves are cycled and inspected, and sensor probes are assessed for fouling versus wiring failure. 04. **Repair and structural check** Lines are repaired with crimped or cinched fittings verified by gauge, tanks are plastic welded with matched rod or replaced, and any softened support shelf or rotted subfloor under a leak is addressed rather than covered back up. 05. **Sanitize and verify** The fresh system is sanitized, flushed and pressure tested again, every fixture is run to full flow, and the waste side is filled and drained to confirm the tanks empty cleanly and the sensors read through the range. ## Applies to - [Class A Motorhome](https://ocrv.life/vehicles/rvs-motorhomes/class-a-motorhome) - [Class C Motorhome](https://ocrv.life/vehicles/rvs-motorhomes/class-c-motorhome) - [Class B Camper Van](https://ocrv.life/vehicles/rvs-motorhomes/class-b-camper-van) - [Fifth Wheel](https://ocrv.life/vehicles/campers-trailers/fifth-wheel) - [Travel Trailer](https://ocrv.life/vehicles/campers-trailers/travel-trailer) - [Toy Hauler](https://ocrv.life/vehicles/campers-trailers/toy-hauler) - [Truck Camper](https://ocrv.life/vehicles/campers-trailers/truck-camper) - [Bus Conversion and Skoolie](https://ocrv.life/vehicles/rvs-motorhomes/bus-conversion-skoolie) - [Sprinter Van](https://ocrv.life/sprinter-van-repair) - [Food Truck](https://ocrv.life/vehicles/mobile-business/food-truck) - [Mobile Medical Clinic](https://ocrv.life/vehicles/mobile-business/mobile-medical-clinic) ## Questions **My tank sensors always read full. Can you actually fix that?** Yes, and there are two paths. Aggressive tank cleaning with a rinse wand and the right chemistry clears residue bridging the internal probes, which restores accuracy for a while. The permanent solution is converting to external sensors that read through the tank wall and cannot foul. On coaches where the owner has fought this for years, the conversion is usually the better money. **Can a cracked black tank be repaired or does it have to be replaced?** A single clean crack in sound polyethylene can be plastic welded with matched rod and will hold indefinitely. Adhesives and epoxies will not, regardless of what the packaging claims, because nothing bonds reliably to polyethylene. If the tank has multiple cracks, damage at a fitting boss, or material that has gone chalky from age, replacement is the honest call and we will tell you so. **Do I really need a water pressure regulator?** Yes. RV plumbing is built for around sixty psi and campground supply routinely runs higher, particularly overnight when demand falls off. A brass adjustable regulator with a gauge costs very little and prevents split fittings, a failed toilet valve seat and a water heater relief valve that keeps dumping. It is the least expensive protection you can put on the coach. **Why does my water pump run when nothing is turned on?** The pump is replacing pressure it is losing somewhere. That is a leak, a failed check valve inside the pump head, a toilet valve seeping into the bowl, or a waterlogged accumulator tank that has lost its air charge. We pressure test the system to separate a genuine leak from an internal pump fault, because replacing the pump when the toilet is the culprit fixes nothing. **Is my water damage covered by insurance?** It depends on how the water arrived. A line that burst or a fitting that suddenly let go is generally a covered sudden discharge. A fitting that has been weeping quietly for months is generally excluded as gradual damage. We document the failed component, the moisture pattern and the meter readings on every intrusion job so the file supports whichever conversation you end up having with your carrier. **Should I winterize if I only store the coach in Orange County?** Probably not for the storage itself, since freezing at sea level here is rare. The question is where you travel. A weekend at Big Bear or a trip through the Sierra in shoulder season will freeze an unprotected line, and a split behind a wall is expensive out of all proportion to the prevention. We handle line blowout and antifreeze service for owners who go to elevation.