FixGas or Diesel Leaking — What It Is, and What It Costs
The smell of gasoline, a wet streak along the frame, or a drip after filling up — a fuel leak is the one leak that is a safety issue first and a repair second. These visits end most often in fuel lines and hoses, with tanks and their fittings behind them.
This page is a focused cut of the broader Fluid Leaking From Car records.
What it actually turns out to be
| The fix involved | Share of visits* | Typical cost† | Median |
|---|---|---|---|
| Fuel Line | 23.0% | $125 – $420 | $220 |
| Hose | 17.4% | $103 – $387 | $207 |
| Fuel Tank | 13.9% | $167 – $579 | $323 |
| Gasket / Seal | 8.8% | $65 – $444 | $188 |
| Pipe / Tube | 8.7% | $26 – $196 | $65 |
| Brake Line | 3.8% | $130 – $339 | $207 |
| Brake Fluid | 3.2% | $106 – $366 | $203 |
| Other, rarer causes | smaller shares | varies | — |
*Share of visits whose repair involved this part. Combined repairs count toward each
part involved, so shares overlap and don't add up to 100%. Among visits that ended in a parts repair.
†Middle half of real invoices (25th–75th percentile) when this was the only fix — parts + labor, all vehicle types.
Real repair reports
These are recent, paid visits for this complaint — the words as the owner said them, and what it turned out to be.
Car owners said
“Diagnose Fluid Leak (fuel)”
“Inspect fuel system for a leak”
“Customer states fuel leak”
“Diagnose and repair fuel leak”
“Fuel leak? check and advise”
“fuel leak on top of tank”
What the technician found
“Replaced transfer pump, verified no leak reinstalled rear seat”
“**FUEL LEAK TANK AREA** **trace issue to line coming off fuel pump , recommend replace fuel pump assembly.**”
Take the smell seriously
A persistent raw-fuel smell deserves a same-week look, parked outside in the meantime. Shops treat fuel leaks as repair-now work, and no honest one will patch a fuel line and send it away — sections get replaced with fuel-rated line.
Where lines fail
Steel fuel lines run beside the brake lines under the car and rust the same way; rubber sections age at their clamps. Leaks concentrated near the tank or along the rocker panels are this family — the most common outcome in these records.
Tank leaks
A drip that appears right after a fill-up points at the top of the tank: the filler neck, seams, or the pump module seal. Since the tank comes down for the repair, an aging fuel pump is often replaced in the same labor.
Take this to the shop
The FixDozer Diagnosis Brief puts this page on one printable sheet: what this complaint usually turns out to be, how often, and what each fix should cost — so when the diagnosis comes back, you already know whether the number fits.
Download the Diagnosis Brief (PDF)View it online · Narrow it down for your vehicle