RV Plumbing and Tank Repair in Brea, CA
RV plumbing repair in Brea, CA covers three separate water systems that share a coach and almost nothing else: fresh water under pressure, gray water draining by gravity, and black water sitting in a tank until you dump it. We repair and replace polyethylene and ABS holding tanks, rebuild and reroute PEX and legacy polybutylene supply lines, replace pumps, check valves, and termination valves, and service Suburban, Atwood, Truma, and AquaHot water heaters. Freeze splits, dropped tanks, weeping fittings, and failed macerators are the everyday work at our shop.
The boundary for this page is water inside pipes and tanks. Water that has already escaped and reached the subfloor, the wall lamination, or the frame is a different repair with a different sequence, and it belongs to our water damage and subfloor page. We routinely do both on the same coach, but the plumbing gets fixed first, because rebuilding a floor under a line that still leaks is money spent twice.
- California BAR licensed ARD00288521
- 35,000 square feet facility
- All work performed in shop at our Yorba Linda facility
- Direct billing with 16 carriers on covered claims
Ready to get this looked at?
Electrical and systems faults get bench time, not guesswork. Diagnostic time is credited against the repair when you authorize the work.
What this repair covers
A typical motorhome carries between 180 and 400 feet of supply line, three to six tanks depending on layout, twenty or more crimp or expansion fittings, and a pump that cycles thousands of times a season. Any one of those points can leak, and the leak rarely appears where the water shows up. Our work starts by proving the system holds pressure and ends by proving it again.
Tank work is the heavy end of this page. Fresh tanks are usually rotomolded polyethylene, gray and black tanks are polyethylene or ABS, and each material demands a different repair method. A tank that can be plastic welded gets welded. A tank with a seam split or a cracked hub gets replaced.
Scope for this page:
- In scope: fresh, gray, and black tank cracks, hub failures, weld repair, and full replacement.
- In scope: PEX and polybutylene supply line replacement, rerouting, and fitting failures.
- In scope: water pumps, accumulators, pressure switches, check valves, and city water inlets.
- In scope: termination valves, blade seals, cable and lever linkages, and macerator pumps.
- In scope: water heaters from Suburban, Atwood, Truma, and hydronic AquaHot domestic coils.
- In scope: freeze split repair, low point drains, bypass valves, and winterization plumbing.
- In scope: toilets, flanges, foot pedal valves, showers, faucets, and P traps.
- Out of scope: rotten subfloor, delaminated walls, and mold remediation from a past leak.
Damage and failure modes we see
Water systems fail at joints, at temperature extremes, and at anything with a moving seal. Below are the failures that account for most of what comes through the door, and what each one costs you if you leave it.
Polybutylene supply line and crimp ring failure
Coaches built roughly between 1985 and the late 1990s carry gray polybutylene supply line with acetal fittings and copper or aluminum crimp rings. The plastic itself becomes brittle with age and oxidizer exposure, and the fittings crack at the barb shoulder. The classic symptom is a pinhole weep that shows up as a damp spot in a cabinet base, dries between trips, and comes back.
There is no partial fix worth doing on a coach with widespread polybutylene. Splicing one failure buys you weeks. We quote full replacement in PEX with expansion or copper crimp fittings, run through the same chases, because the second and third failures are already scheduled whether you know it or not.
Freeze splits and the bypass valve nobody moved
Brea rarely freezes hard, but coaches travel. A single overnight below freezing in a mountain campground with a full fresh tank and no winterization splits the pump head, the low point drain tees, and the water heater tank. Owners then blow out the lines in spring, find nothing, and get a flood on the first pressurized fill.
The most expensive version of this is a water heater bypass valve left in the normal position during a pink antifreeze fill. Six gallons of antifreeze go into the heater tank instead of the lines, the lines stay wet, and everything downstream splits. The delay cost here is real: a split in a wall chase can run for hours before anyone notices, and that is how a plumbing job becomes a subfloor job.
Black tank cracks, dropped tanks, and hub failure
Holding tanks hang from steel or aluminum straps under the floor, often with nothing but the straps carrying several hundred pounds of water on a moving vehicle. Straps rust or fatigue, the tank sags, and the first thing to go is the hub where the three inch dump fitting is spin welded to the tank body. That joint is the weak point on nearly every tank ever built.
The other common crack starts at a support gap and runs along the flat bottom panel. Symptom is odor with no visible drip, because black water wicks into insulation and coroplast underbelly before it finds a low spot. Left alone, sewage saturated insulation rots the floor above it, and now you have a structural repair instead of a tank repair.
Termination valve seal wear and stuck blades
The blade valve at the dump outlet uses two flat seals compressed against a plastic gate. Toilet paper fibers, hard water scale, and dried solids abrade the seals and score the blade. First symptom is a valve that needs both hands. Second is a slow drip at the dump cap, which owners live with far longer than they should.
Cable operated valves in a fifth wheel stretch their cable housings and lose travel until the blade no longer fully closes. Replacing the seal without replacing the cable gets you a valve that still leaks, which is why we test blade travel with the valve body off the tank rather than assuming.
Water heater tank corrosion and anode neglect
Suburban water heaters use a steel tank with a porcelain lining and a sacrificial magnesium or aluminum anode rod that is supposed to be inspected annually. Almost nobody does. Once the anode is consumed the lining pinholes at the bottom seam and the tank is done, since a Suburban tank is not repairable. Atwood and certain Dometic units use an aluminum clad tank with no anode at all, and putting an anode in one of those actively causes damage.
Truma AquaGo and hydronic AquaHot domestic coils fail differently. Their problem is scale from hard water, which insulates the heat exchanger, drops output temperature, and eventually blocks flow. Descaling on a schedule keeps them alive. Ignoring it means a heat exchanger.
Pump chatter, check valve failure, and pressure switch drift
A Shurflo or Aquatec diaphragm pump that cycles rapidly with no tap open has lost its internal check valve, has a leak somewhere downstream, or has an air charge problem in the accumulator. Owners tolerate the chatter, but every cycle is a start current spike, and the pump motor brushes and the pressure switch contacts both wear on cycles rather than on hours.
Pressure switch drift is quieter and more damaging. A switch that stops cutting out lets pressure climb until a fitting somewhere gives up, and the fitting that gives up is rarely convenient. Pumps are cheap. What they take out when they fail open is not.
How we perform this repair
Water follows gravity and hides its origin, so we never chase a stain. We pressurize, isolate, and prove.
The standard sequence on a leak or tank complaint:
- Isolate and air test the fresh system. We cap the outlets, connect a regulated air source at the city water inlet, bring the system to roughly 40 to 50 psi, and watch a gauge for fifteen minutes. A system that drops a single psi has a leak, and we know that before removing a panel.
- Locate with soap solution and a listening approach at fittings and chase entries. Where a chase is inaccessible we use a low pressure smoke or a moisture meter grid across the floor to narrow it before opening anything.
- Dye test the drain and holding tanks. Fluorescent tracer in the gray or black tank plus an ultraviolet lamp in the underbelly finds a hub crack in minutes that could take a day of visual inspection.
- Drop the coroplast underbelly and inspect straps, hangers, and tank supports. Rusted strap hardware gets replaced with stainless, and any tank we reinstall gets full width support rather than the original two strap arrangement where the layout allows.
- Repair or replace to material. Polyethylene tanks get hot air plastic welding with matched HDPE or polypropylene rod, ABS gets solvent weld with reinforcing plate, and any tank with a failed spin welded hub or a seam split gets replaced rather than patched.
- Rebuild supply lines in PEX. Runs get sized and clamped every 32 inches, routed away from heat sources and sharp frame edges, and terminated with expansion or copper crimp fittings. Push to connect fittings do not go inside a wall on a vehicle that vibrates for a living.
- Retest at pressure, then wet test with water for a minimum of thirty minutes with the pump cycling, tanks filled to capacity, and every fitting checked by hand before the underbelly closes.
What this costs and how we quote it
Plumbing is quoted by access first and parts second. The fitting is inexpensive. Getting to the fitting behind a bathroom wall, under a slide floor, or above a tank that has to come out is where the hours go, and no honest estimate can be given over the phone without knowing which of those applies.
Leak location is billed as diagnostic time and credited against the authorized repair. Tank replacement is quoted as a unit: tank, straps and hardware, fittings, sealants, underbelly repair, and labor to drop and reinstall. Supply line replacement is quoted by run count and access difficulty rather than by linear foot, since a straight run through an open bay and a run through a sealed chase cost nothing alike. Water heater work is quoted separately from the plumbing that feeds it. See our pricing page for current rates and the credit policy.
Vehicles we perform this on
Tank access is entirely a platform question. A fifth wheel usually gives you a full width enclosed underbelly and reachable tanks. A Class A on a raised rail chassis buries them between frame rails with an exhaust and a driveshaft in the way. A camper van conversion may have a single 20 gallon tank under a bench, and a park model plumbs to a site connection with no tanks at all.
What this page does not cover
- rotted subfloor, soft spots, and structural water damage The consequence of a leak, repaired after the leak is stopped.
- roof membrane and sealant leaks Water entering from outside the coach, not from the plumbing.
- sidewall delamination caused by long term moisture Panel bond failure has its own repair method.
Get a written scope before the damage spreads
Electrical and systems faults get bench time, not guesswork. Diagnostic time is credited against the repair when you authorize the work.
If this damage is on an insurance claim
Plumbing failures split cleanly into two categories on a claim, and which one you are in decides everything. A pipe that failed because it was thirty years old is wear, and wear is not a covered peril. A pipe that split because of a sudden freeze event, or a tank cracked by road debris or a collision, often is covered.
The consequential damage is where the money is. Even where a policy excludes the failed component itself, it may cover the resulting damage to the floor, walls, and cabinetry. That is why we photograph the failure point and write a cause of loss statement before we cut anything out. Our page on water and storm claims explains how carriers separate the two.
Why Brea owners bring this work to us
Plumbing work needs a coach on level ground, on air, with the underbelly open and water running for an hour without anyone worrying about a driveway. That is a shop job, not a driveway job, and it is the main reason Brea owners drive down to us on La Palma Ave in Yorba Linda instead of calling a mobile technician who cannot pressure test a system properly from the curb.
We have been doing this since 2015, we hold California Bureau of Automotive Repair license ARD00288521 and EPA identification CAL000367879, and black water work in particular has disposal requirements that a residential driveway cannot legally meet. We are in shop only: no mobile calls, no roadside service, no route visits.
Frequently asked questions
Can a cracked RV holding tank be repaired or does it need replacing?
A crack in the flat body of a polyethylene tank can usually be hot air plastic welded with matched rod and reinforced, and that repair holds. A crack at the spin welded dump hub, a split along a molded seam, or a tank that has been sagging long enough to distort should be replaced. We make that call after the underbelly is open and the tank is clean enough to actually see, not from a photograph.
Should I replace polybutylene water lines even if they are not leaking yet?
On a coach old enough to have gray polybutylene, yes, plan for it. The material embrittles with age and the acetal fittings crack at the barb shoulder, so failures cluster once they start. Replacing the whole system in PEX during a planned shop visit costs far less than repairing one failure at a time and paying for the water damage that follows each one.
Why does my water pump keep cycling when no tap is open?
Short cycling with everything closed means the system is not holding pressure, which is either an internal pump check valve, a leak downstream, or a waterlogged accumulator with no air charge. The order to check is accumulator, then pump check valve, then a static pressure test to find the leak. Living with the chatter wears out the pressure switch contacts and the motor, and eventually something blows open.
Does my RV water heater need an anode rod?
It depends entirely on the tank material. Suburban heaters use a steel tank with a porcelain lining and require a sacrificial magnesium or aluminum anode, inspected yearly and replaced when about 75 percent consumed. Atwood and similar aluminum clad tanks have no anode and should never have one installed, since introducing one in that tank causes the corrosion it is meant to prevent.
What causes a persistent sewer odor with no visible leak?
Most often a dry P trap, a failed toilet flange seal, or a cracked vent stack, but in coaches the sneaky one is a black tank hub crack weeping into the underbelly insulation. Nothing drips because the coroplast holds it, and the smell rises through floor penetrations. A fluorescent dye test with an ultraviolet lamp under the coach finds it quickly.
How do you find a leak inside a wall without tearing the wall apart?
We air test the isolated fresh system at regulated pressure and watch a gauge, which tells us a leak exists and roughly how large. Then we isolate branches to narrow the run, use soap solution at every accessible fitting, and map the floor and lower wall with a pinless moisture meter on a grid. Opening a panel is the last step, not the first.
Is a macerator worth adding to an RV?
It is worth it if you regularly dump to a residential cleanout, a portable tote, or a site without a gravity connection at the right height. A macerator grinds solids and pumps through a small hose, which trades a three inch gravity drop for a slower pumped discharge. It adds an impeller and a motor that will eventually need service, and it should never be the only discharge path on the coach.
How long does a holding tank replacement take?
Plan on multiple days in the shop rather than an afternoon. The underbelly has to come down, the tank has to be drained and cleaned before anyone can work near it, straps and hangers usually need replacing, tank availability varies since many are model specific, and the new install gets wet tested before the underbelly closes. Rushing any of those steps produces a tank that leaks again in a season.
Written and reviewed by the OCRV Center Technical Team. Last updated .
Book your paid estimate
Electrical and systems faults get bench time, not guesswork. Diagnostic time is credited against the repair when you authorize the work.
Related repairs and pages
- subfloor rot and water damage repairWhere the job goes once water has reached the structure.
- roof and sealant leak repairThe other major water entry path, from above rather than inside.
- refrigerator, cooktop, and appliance workAppliances that connect to plumbing but are diagnosed separately.
- furnace and hydronic heating serviceAquaHot burners and zone heating, separate from the domestic hot water coil.
- fifth wheel plumbing access
- diesel pusher tank work
- travel trailer repairs
- camper van water systems
- park model plumbing
- how carriers handle water damage claimsSudden failure against long term seepage decides coverage.
- what leak location and tank work are quoted against
- our intake and authorization process
- book a plumbing diagnosis