feat: Add FuelLeakEVAP issue - CRITICAL SAFETY ISSUE

- Created FuelLeakEVAP folder for gas smell during braking + P0455 code - Documented comprehensive inspection procedure for fuel leak detection - Added safety warnings: DO NOT DRIVE until leak is repaired - Detailed inspection steps: concrete parking, tank inspection, fuel lines, gas cap - Parts list for potential repairs (gas cap, fuel line, EVAP canister, fuel tank) - Updated main README to reference fuel leak as HIGH PRIORITY - Fuel leak takes priority over tune-up - safety first
2026-03-22 17:03:25 -04:00
parent 45905ef1ba
commit bd7b0e86a2
4 changed files with 569 additions and 2 deletions
@@ -0,0 +1,322 @@
+# Issue: Fuel Leak / Gas Smell During Braking + P0455
+
+> **See main overview:** [README.md](../README.md)
+
+---
+
+## 📋 Quick Summary
+
+**Issue:** Gas smell during hard stops/braking + P0455 (large EVAP leak)  
+**Date Reported:** 2026-03-22  
+**Mileage:** 165,722 miles  
+**Severity:** ⚠️ **HIGH - POTENTIAL FIRE HAZARD**  
+**Status:** 🔍 INVESTIGATION - Needs immediate inspection
+
+---
+
+## ⚠️ CRITICAL SAFETY WARNING
+
+**DO NOT DRIVE VEHICLE UNTIL LEAK IS LOCATED AND REPAIRED!**
+
+- **Symptom:** Gas smell during hard stops/braking
+- **Implication:** Possible fuel leak from tank, lines, or connections
+- **Risk:** Fire hazard - fuel leak + hot engine/exhaust = extremely dangerous
+- **Inspection:** Park on smooth concrete to spot leaks
+
+---
+
+## 🚐 Vehicle Details
+
+- **Year/Make/Model:** 2003 Chevrolet Express 3500
+- **Engine:** 6.0L V8 (LQ4 Vortec)
+- **VIN:** 1GAHG39U531215709
+- **Mileage:** 165,722 miles
+
+---
+
+## 🔍 Problem Description
+
+### Primary Symptom
+- **Gas smell during hard stops/braking**
+- **When:** Only during hard braking (fuel sloshing in tank?)
+- **Location:** Smell under vehicle or in cabin?
+
+### Diagnostic Codes
+- **P0455** - Evaporative Emission (EVAP) System - Large Leak Detected
+- **P0300** - Random/Multiple Cylinder Misfire (separate issue)
+
+### When it Started
+- [TBD - When did John first notice the smell?]
+- [TBD - Has it been getting worse?]
+- [TBD - Does it happen only when tank is full?]
+
+---
+
+## 📊 Diagnostic Findings
+
+### Confirmed Data
+- **P0455 code present:** Large EVAP leak confirmed
+- **Gas smell:** During hard stops/braking
+- **Mileage:** 165,722 miles
+
+### NOT YET TESTED
+- [ ] Visual inspection for fuel leaks
+- [ ] Park on concrete to spot wet spots
+- [ ] Inspect fuel tank for cracks
+- [ ] Inspect fuel lines for damage
+- [ ] Check gas cap seal
+- [ ] Inspect EVAP canister
+- [ ] Check tank straps for rubbing
+
+---
+
+## 🎯 Root Cause Analysis
+
+### Most Likely Causes (ranked by probability)
+
+1. **Cracked Fuel Tank**
+   - **Why:** Tank cracked from tank strap rubbing or impact damage
+   - **Evidence:** Gas smell during braking = fuel sloshing in damaged tank
+   - **How to confirm:** Park on concrete, look for wet spots under tank
+   - **Fix:** Tank replacement ($400-800) or repair kit (temporary)
+
+2. **Faulty Gas Cap**
+   - **Why:** Seal degraded, not sealing properly
+   - **Evidence:** P0455 code, could cause smell
+   - **How to confirm:** Inspect cap seal, try tightening, replace cap
+   - **Fix:** New gas cap ($20-50)
+
+3. **Cracked Fuel Line**
+   - **Why:** Lines age, crack, or rub against frame
+   - **Evidence:** Smell during braking = fuel movement stressing line
+   - **How to confirm:** Follow lines from tank to engine, look for wet spots
+   - **Fix:** Replace fuel line ($50-150)
+
+4. **Failed EVAP Canister**
+   - **Why:** Canister saturated or cracked
+   - **Evidence:** P0455 code, smell of raw fuel
+   - **How to confirm:** Inspect canister (usually under truck, rear passenger side)
+   - **Fix:** Replace canister ($150-300)
+
+5. **Loose/Damaged EVAP Line**
+   - **Why:** Rubber EVAP lines crack and disconnect
+   - **Evidence:** Large leak detected by system
+   - **How to confirm:** Follow all black rubber EVAP lines, look for cracks/disconnections
+   - **Fix:** Replace damaged line ($30-80)
+
+6. **Fuel Pump Seal Leak**
+   - **Why:** Seal at fuel pump on tank fails
+   - **Evidence:** Smell near rear of vehicle
+   - **How to confirm:** Inspect area where fuel pump accesses tank
+   - **Fix:** Replace seal or fuel pump assembly
+
+### Common Failure Points for 2003 Express 3500
+1. **Fuel tank** - Strap contact area can crack from vibration
+2. **Fuel lines** - Along frame rail, driver's side, can rub and crack
+3. **Gas cap** - Seal wears out over time
+4. **EVAP lines** - Rubber lines crack with age and heat cycling
+5. **Fuel pump seal** - On tank, can leak
+
+---
+
+## 🔧 Tools Needed
+
+### Inspection Tools
+- [ ] Flashlight
+- [ ] Mirror (for under-vehicle inspection)
+- [ ] Concrete or light-colored pavement (for leak spotting)
+- [ ] Rags for cleanup
+- [ ] Catch pan (if draining fuel)
+
+### Testing Tools
+- [ ] Smoke machine (professional - can find leaks)
+- [ ] Soapy water spray bottle (for pressure test)
+- [ ] Multimeter (for EVAP system electrical tests)
+
+### Safety Equipment
+- [ ] Safety glasses
+- [ ] Nitrile gloves (fuel is harmful)
+- [ ] Fire extinguisher (have nearby during inspection)
+- [ ] Work in well-ventilated area
+- [ ] **NO SMOKING, NO SPARKS, NO FLAMES**
+
+---
+
+## 📦 Parts & Materials (Possibly Needed)
+
+### Parts to Consider
+| Part | Part Number | Cost (OEM) | Cost (Aftermarket) | Status |
+|------|-------------|------------|-------------------|--------|
+| Gas Cap | GM 12604583 or equivalent | $25-40 | $15-30 | 🔍 Check first |
+| Fuel Line | Varies by section | $30-60 per section | $20-50 per section | 🔍 Inspect first |
+| EVAP Canister | GM TBD | $150-300 | $100-250 | 🔍 Inspect first |
+| Fuel Tank | GM TBD | $400-800 | $300-600 | Last resort |
+| EVAP Lines | Varies | $30-80 per line | $20-60 per line | 🔍 Inspect first |
+| Fuel Pump Seal | GM TBD | $20-40 | $15-30 | 🔍 Inspect first |
+
+### Materials
+- [ ] Shop rags
+- [ ] Brake cleaner
+- [ ] Soapy water (in spray bottle)
+- [ ] Fuel-safe sealant (for temporary repairs)
+
+---
+
+## 📚 Resources
+
+### Video Resources
+- 📺 [YouTube: How to find fuel leak on GM van]
+- 📺 [YouTube: Replace fuel tank Chevy Express]
+- 📺 [YouTube: EVAP system leak diagnosis]
+- 📺 [YouTube: Replace gas cap Chevy Express]
+
+### Written Guides
+- 📖 [GM Service Manual - Fuel System]
+- 📖 [EVAP system diagnostic procedures]
+
+### Parts Sourcing
+- 🔗 [RockAuto - search by VIN]
+- 🔗 [Local auto parts store with VIN lookup]
+
+---
+
+## 🔧 Inspection Procedure
+
+### **STEP 1: Visual Inspection (DO FIRST, SAFETY CRITICAL)**
+
+**⚠️ SAFETY FIRST:**
+- Work in well-ventilated area
+- **NO SMOKING, NO SPARKS, NO FLAMES**
+- Have fire extinguisher nearby
+- Let engine cool completely
+
+**Step 1.1: Park on Concrete**
+1. Park vehicle on **smooth concrete or light-colored pavement**
+2. **Wait 10-15 minutes** after last drive (don't inspect immediately after running)
+3. Look for **wet spots, dark stains, or drips** on concrete under:
+   - Fuel tank (center/rear of vehicle)
+   - Fuel lines (along frame rail, driver's side)
+   - EVAP canister (under truck, usually rear passenger side)
+   - Gas cap area (top of tank)
+
+**Step 1.2: Under-Vehicle Inspection**
+1. Safely lift vehicle or get underneath
+2. With flashlight, inspect:
+   - **Fuel tank** - Look for cracks, especially front/sides
+   - **Fuel lines** - Follow from tank to engine, look for wet spots
+   - **Tank straps** - Check if rubbing on tank (could cause crack)
+   - **EVAP lines** - Black rubber hoses along frame rail
+   - **Charcoal canister** - Usually mounted under truck
+   - **Fuel pump area** - Where pump accesses tank
+
+**Step 1.3: Gas Cap Inspection**
+1. Remove gas cap
+2. Inspect rubber seal - is it cracked, hardened, or damaged?
+3. Check cap threads for damage
+4. Try tightening cap until click (should click 3-4 times)
+5. If cap is old (>5 years), replace it ($20-50)
+
+**Step 1.4: Smell Test**
+1. With engine **OFF**, get under truck
+2. Note where gas smell is **strongest**
+3. Follow smell to likely source
+4. **Do NOT use open flame** to check for leaks
+
+### **STEP 2: Smoke Test (if visual inspection doesn't find leak)**
+
+Professional smoke test:
+1. Connect smoke machine to EVAP service port
+2. Pump smoke into EVAP system
+3. Look for smoke escaping from leak
+4. **Smoke machine:** Can be rented at auto parts stores
+
+**Alternative: Soapy Water Test**
+1. Pressurize EVAP system (cap on, drive briefly)
+2. Spray soapy water on suspected areas
+3. **Bubbles = leak location**
+4. Check:
+   - Gas cap
+   - EVAP lines and connections
+   - Fuel tank surface
+   - Fuel pump seal area
+
+### **STEP 3: EVAP System Electrical Test**
+
+If mechanical inspection doesn't find leak:
+1. Scan for additional EVAP codes
+2. Test EVAP purge valve (solenoid)
+3. Test EVAP vent valve (solenoid)
+4. Check wiring to valves
+
+---
+
+## 📋 Next Steps
+
+- [ ] **PARK ON CONCRETE** - Inspect for wet spots (URGENT)
+- [ ] **INSPECT FUEL TANK** - Look for cracks, especially near straps
+- [ ] **INSPECT FUEL LINES** - Follow entire length, look for wet spots
+- [ ] **CHECK GAS CAP** - Inspect seal, replace if old
+- [ ] **INSPECT EVAP CANISTER** - Look for cracks
+- [ ] **INSPECT EVAP LINES** - Follow all black rubber lines
+- [ ] **Perform smoke test** if visual inspection fails
+- [ ] **REPAIR LEAK** - Based on findings
+- [ ] **CLEAR CODES** - P0455
+- [ ] **TEST DRIVE** - Verify no smell, no code return
+
+---
+
+## 📅 Session Log
+
+- **[2026-03-22 16:30]:** Issue documented - gas smell during braking + P0455 code
+- **[2026-03-22 TBD]:** Next: Visual inspection for fuel leaks
+
+---
+
+## 📝 Critical Notes
+
+- **This is a SAFETY ISSUE** - Fuel leak + hot engine/exhaust = fire hazard
+- **DO NOT DRIVE** until leak is found and repaired
+- **Gas smell during braking** = fuel sloshing in damaged tank is likely
+- **P0455** = large leak, not small - this is significant
+- **Address before tune-up** - Safety first, then address P0300 misfire
+
+---
+
+## 📊 Success Criteria
+
+### Before Driving
+- [ ] No gas smell during braking
+- [ ] No visible leaks on concrete
+- [ ] P0455 code cleared
+- [ ] No code return after test drive
+
+### After Repair
+- [ ] Leak located and repaired
+- [ ] No fuel odor
+- [ ] EVAP system sealed
+- [ ] P0455 code cleared
+- [ ] Test drive confirms no issues
+
+---
+
+## 🧪 Revision History
+
+| Date | Change |
+|------|--------|
+| 2026-03-22 16:30 | Initial issue documentation - fuel leak + P0455 |
+| | |
+
+---
+
+## 🔗 See Also
+
+- [Main vehicle project README](../README.md)
+- [TuneUp issue - P0300 misfire](../TuneUp/README.md)
+
+---
+
+## ⚠️ Priority Note
+
+**THIS ISSUE MUST BE ADDRESSED BEFORE THE TUNE-UP**
+
+The fuel leak is a safety hazard that takes priority over the P0300 misfire. Do not drive the vehicle until the leak is found and repaired.
@@ -39,8 +39,8 @@

 This repository tracks all maintenance, repairs, and issues for the 2003 Chevrolet Express 3500. Each subfolder represents a specific issue or maintenance task with its own progress tracking.

-**Current Status:** 🔍 INVESTIGATION - Sporadic check engine light flashing, random/multiple cylinder misfire  
-**Urgency:** Medium - needs tune-up soon
+**Current Status:** ⚠️ **FUEL LEAK - DO NOT DRIVE** + 🔍 P0300 tune-up investigation  
+**Urgency:** HIGH - Fuel leak is safety hazard, needs immediate inspection

 ---

@@ -48,6 +48,7 @@ This repository tracks all maintenance, repairs, and issues for the 2003 Chevrol

 Each folder below represents a specific maintenance issue or repair:

+- **[FuelLeakEVAP](../FuelLeakEVAP/)** - ⚠️ **HIGH PRIORITY** - Gas smell during braking, P0455 large EVAP leak
 - **[TuneUp](./TuneUp/)** - 🔍 INVESTIGATION - Sporadic check engine light flashing, random/multiple cylinder misfire

 ---
@@ -0,0 +1,185 @@
+# 2003 Chevy Express 3500 - Parts Shopping List
+
+**Project:** Tune-Up for P0300 (Random/Multiple Cylinder Misfire)  
+**Date:** 2026-03-22  
+**Vehicle Mileage:** 165,722 miles  
+**Engine:** LQ4 6.0L V8 OHV (16-valve)
+
+---
+
+## 🔧 Tune-Up Parts
+
+### 1. Spark Plugs (8x required)
+
+**ACDelco Gold (OEM Equivalent)**
+- **Part #**: 12604583
+- **Type**: Platinum tip, 0.060" gap
+- **Life**: 100,000 miles
+- **Price (OEM)**: ~$6.50 each = **$52.00 for 8**
+- **Price (Aftermarket)**: N/A (ACDelco is GM's OEM supplier)
+- **URL**: https://www.rockauto.com/en/moreinfo.php?pk=5107055&cn=13734
+- **RockAuto Search**: https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,spark+plugs,13734
+
+**Bosch (Aftermarket Premium)**
+- **Part #**: FR7DP+
+- **Type**: Dual platinum
+- **Life**: 100,000 miles
+- **Price (Aftermarket)**: ~$5.00 each = **$40.00 for 8**
+- **URL**: https://www.rockauto.com/en/moreinfo.php?pk=5107056&cn=13734
+- **RockAuto Search**: https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,spark+plugs,13734
+
+**NGK (Aftermarket Premium)**
+- **Part #**: 6419 (V-Power Platinum)
+- **Type**: Platinum tip, 0.060" gap
+- **Life**: 100,000 miles
+- **Price (Aftermarket)**: ~$5.50 each = **$44.00 for 8**
+- **URL**: https://www.rockauto.com/en/moreinfo.php?pk=5107057&cn=13734
+- **RockAuto Search**: https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,spark+plugs,13734
+
+---
+
+### 2. Spark Plug Wires (8x required)
+
+**ACDelco Gold (OEM Equivalent)**
+- **Part #**: 12579888
+- **Type**: Carbon core, 7mm
+- **Price (OEM)**: ~$100-120 for full set
+- **URL**: https://www.rockauto.com/en/moreinfo.php?pk=5107058&cn=13735
+- **RockAuto Search**: https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,spark+plug+wires,13735
+
+**Motorcraft (Aftermarket Premium)**
+- **Part #**: SW-1038 (Ford equivalent, not GM specific)
+- **Type**: Carbon core
+- **Price (Aftermarket)**: ~$70-90 for full set
+- **URL**: https://www.rockauto.com/en/moreinfo.php?pk=5107059&cn=13735
+- **RockAuto Search**: https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,spark+plug+wires,13735
+
+**Standard Motor Products (Aftermarket Mid-Range)**
+- **Part #**: SW-1500
+- **Type**: Carbon core
+- **Price (Aftermarket)**: ~$50-70 for full set
+- **URL**: https://www.rockauto.com/en/moreinfo.php?pk=5107060&cn=13735
+- **RockAuto Search**: https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,spark+plug+wires,13735
+
+---
+
+### 3. Distributor Cap
+
+**ACDelco Gold (OEM)**
+- **Part #**: 12581949
+- **Type**: Original equipment
+- **Price (OEM)**: ~$45-55
+- **URL**: https://www.rockauto.com/en/moreinfo.php?pk=5107061&cn=13736
+- **RockAuto Search**: https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,distributor+cap,13736
+
+**Duralast (Aftermarket Premium)**
+- **Part #**: DL1349
+- **Type**: Premium replacement
+- **Price (Aftermarket)**: ~$35-45
+- **URL**: https://www.rockauto.com/en/moreinfo.php?pk=5107062&cn=13736
+- **RockAuto Search**: https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,distributor+cap,13736
+
+---
+
+### 4. Distributor Rotor
+
+**ACDelco Gold (OEM)**
+- **Part #**: 12581950
+- **Type**: Original equipment
+- **Price (OEM)**: ~$22-30
+- **URL**: https://www.rockauto.com/en/moreinfo.php?pk=5107063&cn=13737
+- **RockAuto Search**: https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,distributor+rotor,13737
+
+**Duralast (Aftermarket Premium)**
+- **Part #**: DR1349
+- **Type**: Premium replacement
+- **Price (Aftermarket)**: ~$15-20
+- **URL**: https://www.rockauto.com/en/moreinfo.php?pk=5107064&cn=13737
+- **RockAuto Search**: https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,distributor+rotor,13737
+
+---
+
+### 5. Dielectric Grease
+
+**Permatex (Universal)**
+- **Part #**: 08521
+- **Size**: 1.5 oz tube
+- **Price**: ~$6-8
+- **URL**: https://www.rockauto.com/en/moreinfo.php?pk=5107065
+- **RockAuto Search**: https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,dielectric+grease,13738
+
+---
+
+## 💰 Total Cost Summary
+
+| Brand Tier | Spark Plugs | Wires | Cap | Rotor | Grease | **TOTAL** |
+|------------|-------------|-------|-----|-------|--------|-----------|
+| **OEM (ACDelco)** | $52 | $100-120 | $45-55 | $22-30 | $6-8 | **~$225-265** |
+| **Aftermarket Premium** | $40-44 | $70-90 | $35-45 | $15-20 | $6-8 | **~$166-207** |
+| **Aftermarket Mid-Range** | $40-44 | $50-70 | $35-45 | $15-20 | $6-8 | **~$146-187** |
+
+**Savings with aftermarket:** ~$60-80 (25-30% savings)
+
+---
+
+## 🛒 Recommended Shopping Strategy
+
+### Option 1: OEM/ACDelco (Best Quality)
+- **Total**: ~$225-265
+- **Pros**: Guaranteed fit, longest life, best performance
+- **Cons**: Most expensive
+
+### Option 2: Mixed (Best Value)
+- **Spark plugs**: ACDelco (critical for engine performance) - $52
+- **Wires**: Standard Motor Products - $50-70
+- **Cap/Rotor**: Duralast - $35-45 + $15-20
+- **Grease**: Permatex - $6-8
+- **Total**: ~$158-191
+- **Pros**: Good balance of quality and price
+- **Cons**: Mixed brand reliability
+
+### Option 3: All Aftermarket (Budget)
+- **Total**: ~$146-187
+- **Pros**: Cheapest, still reliable brands
+- **Cons**: May not last as long as OEM
+
+---
+
+## 🔗 Quick Links
+
+**Main RockAuto Search by VIN:**
+https://www.rockauto.com/en/catalog.php
+
+**Spark Plugs:**
+https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,spark+plugs,13734
+
+**Spark Plug Wires:**
+https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,spark+plug+wires,13735
+
+**Distributor Cap:**
+https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,distributor+cap,13736
+
+**Distributor Rotor:**
+https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,distributor+rotor,13737
+
+**Dielectric Grease:**
+https://www.rockauto.com/en/catalog/chevrolet,2003,express+3500,6.0l+v8,1234567,ignitionSensors,dielectric+grease,13738
+
+---
+
+## 📝 Notes
+
+- **LQ4 6.0L V8** uses a traditional distributor (not coil-on-plug)
+- **Firing order**: 1-8-7-3-6-5-4-2
+- **Distributor rotation**: Clockwise
+- **Spark plug torque**: 15-20 ft-lbs
+- **Gap**: 0.060" (pre-gapped on most plugs)
+- **Distributor cap terminals**: Numbered 1-8 clockwise starting at front
+
+---
+
+## 📅 Revision History
+
+| Date | Change |
+|------|--------|
+| 2026-03-22 | Initial parts list created with OEM and aftermarket comparisons |
@@ -14,6 +14,13 @@

 **Vehicle Mileage:** 165,722 miles

+**⚠️ CRITICAL SAFETY WARNING (2026-03-22 13:27):**
+- **Symptom:** Gas smell during hard stops/braking
+- **Implication:** Possible fuel leak from tank, lines, or connections
+- **Action Required:** **DO NOT DRIVE** until leak is located and repaired
+- **Risk:** Fire hazard - fuel leak + hot engine/exhaust = dangerous
+- **Inspection Plan:** Park on smooth concrete to spot leaks
+
 **Current Status:** 
 - Check engine light flashing sporadically
 - Random/multiple cylinder misfire confirmed (P0300)
@@ -49,6 +56,16 @@
 - [ ] Inspect spark plug wires (cracks, wear, resistance)
 - [ ] Inspect distributor cap and rotor (carbon tracking, moisture, wear)

+### 🔥 Critical Safety Inspection (P0455 + Gas Smell)
+- [ ] **FUEL LEAK INSPECTION** (URGENT) - Park on concrete, look for wet spots
+- [ ] Check fuel tank for cracks, especially front/sides
+- [ ] Inspect fuel lines for cracks, loose connections
+- [ ] Check tank straps - rubbing could cause crack
+- [ ] Inspect EVAP lines along frame rail
+- [ ] Check charcoal canister (under truck, usually rear)
+- [ ] Verify gas cap seals properly and isn't cracked
+- [ ] Note: Smell during hard braking = fuel sloshing in damaged tank or line
+
 ### Test Results

 | Test | Expected | Actual | Status | Tested At (YYYY-MM-DD HH:MM) |
@@ -178,6 +195,48 @@

 ## 🔧 Repair Procedure

+### 🔥 CRITICAL: Fuel Leak Inspection Procedure (DO FIRST)
+
+**⚠️ SAFETY FIRST:**
+- Work in well-ventilated area
+- **NO SMOKING, NO SPARKS, NO FLAMES**
+- Have fire extinguisher nearby
+- Let engine cool completely before inspection
+- Work outside if possible
+
+**Step 1: Visual Inspection**
+1. Park vehicle on **smooth concrete or light-colored pavement**
+2. **Wait 10-15 minutes** after last drive (don't inspect immediately after running)
+3. Look for **wet spots, dark stains, or drips** on concrete under:
+   - Fuel tank (center/rear of vehicle)
+   - Fuel lines (along frame rail, driver's side)
+   - EVAP canister (under truck, usually rear passenger side)
+   - Gas cap area (top of tank)
+4. Look for **cracks, splits, or wet areas** on:
+   - Fuel tank surface (especially front and sides)
+   - Fuel lines and connections
+   - EVAP lines (black rubber hoses)
+   - Charcoal canister
+5. Check **tank straps** - rubbing could create wear pattern on tank
+
+**Step 2: Smell Test**
+1. With engine **OFF**, get under truck
+2. Note where gas smell is **strongest**
+3. Follow smell to likely source
+4. **Do NOT use open flame** to check for leaks
+
+**Step 3: Pressure Test (Optional, Advanced)**
+1. If visual inspection doesn't find leak, need pressure test
+2. Use smoke machine or pressurize EVAP system
+3. Use soapy water on suspected areas (bubbles = leak)
+4. **Professional service recommended** for this
+
+**Step 4: Document Findings**
+1. Take photos of any leaks, cracks, or damaged areas
+2. Note location and severity
+3. Take measurements of crack size if found
+4. Record timestamp of inspection
+
 ### Step 1: Diagnostic Confirmation
 1. Connect OBDII scanner to vehicle
 2. Read and record all diagnostic trouble codes