Maintenance & Reliability · SOP

Fleet Radiator Core Cleaning And Fin Straightening

This procedure covers the controlled cleaning, flush, fin straightening, and pressure verification of heavy-duty fleet radiator cores. Restores heat transfer efficiency and extends service life between overhauls.

Estimated Time

45 min

Difficulty

Intermediate

Regulation

CSA B52 / ASME

Version

1.0

Free download — no sign‑up, no email.Take this SOP to your shop floor and make it yours.

↓ PDF (print‑ready) ↓ Word (editable)

Purpose

To establish a repeatable, safe process for removing debris, scale, and corrosion from fleet radiator cores and restoring fin geometry. Proper execution prevents overheating, reduces fan engagement cycles, and maintains coolant flow integrity across the fleet.

🌐 Scope

Applies to all fleet vehicles with bolted or welded aluminum/copper-brass radiators. Covers core-only service — does not include header tank replacement, tube repair, or fan clutch diagnostics. Personnel performing this task must be familiar with radiator removal procedures and coolant handling regulations.

Safety Precautions

LOTOLockout/tagout engine start circuit and wait until radiator cap is cool to the touch (below 40°C) before opening system.
PPEWear chemical-resistant gloves, splash goggles, and steel-toe boots. Use hearing protection when operating pressure washer.
COOLCollect drained coolant in a sealed container labeled “Used Glycol.” Dispose per provincial environmental regulations. Never pour down drains.
AIRCompressed air pressure must not exceed 100 psi when blowing through fins to avoid fin distortion or personal injury.

Required Tools & Materials

Pressure washer (1500–2500 psi) with turbo nozzle
Fin comb set — 8, 10, 12, 14 fins-per-inch (FPI)
Radiator flush chemical (compatible with core metal)
Distilled water (minimum 5 gal / 20 L)
Low-pressure compressed air gun with rubber tip
Soft-bristle nylon brush (non-metallic)
pH test strips (range 0–14)
Leak test adapter and pressure pump (0–30 psi gauge)
Coolant drain container & funnel
Cheat sheet: OEM fin count / torque specs for reinstallation

Stop Chasing Maintenance Blindly

Track every calibration, pressure drop reading, and machine performance trend in one place. ServiceGrid logs your tasks automatically and alerts you before failure.

Try ServiceGrid →

Procedure: Step-by-Step

1 Isolate vehicle power and apply lockout/tagout. Allow engine to cool to ambient temperature (verify with IR thermometer).

2 Drain coolant by opening radiator petcock and removing lower hose. Capture all fluid in a sealed container. Dispose per local hazardous waste guidelines.

3 Remove radiator assembly per OEM procedure. Place on a dedicated cleaning stand or work bench with drip tray.

4 Inspect core visually: note areas of fin damage, heavy debris, corrosion, or oil film. Photograph for record if required.

5 Rinse core with pressure washer at ≥1800 psi. Hold nozzle perpendicular to fins, 12–18 inches away. Start from the clean (engine) side to push debris out.

6 Apply radiator flush chemical according to label dwell time (typically 10–15 min). Use a trigger sprayer for even coverage.

7 Flush thoroughly with distilled water. Collect rinse water and test pH. Continue flushing until pH reads 6–8. Confirm no residual detergent.

8 Select the correct fin comb FPI to match radiator. Straighten bent fins in the direction of airflow. Work in small vertical sections; do not over-bend or tear fins.

9 Dry core with low-pressure compressed air (≤100 psi). Blow each fin row perpendicular to tube axis. Remove standing water from headers.

10 Perform a pneumatic leak test: Attach adapter, pressurize to 15 psi, hold for 5 minutes. A pressure drop of ≥1 psi indicates failure — do not reinstall. Mark and tag for repair.

11 Reinstall radiator with new gaskets/seals, torquing bolts to OEM specs. Refill with fresh 50/50 coolant mix. Run engine to operating temp and check for leaks.

Fleet Radiator Core Cleaning And Fin Straightening

Stop Chasing Maintenance Blindly

Software that works like your best tools.