🔧 Express 3500 - Radiator Hose Replacement

Replacing a radiator hose stops coolant leaks and prevents overheating. On your Express 3500, the most common hoses are the upper radiator hose (radiator to engine) and lower radiator hose (radiator to water pump).

Assumption: You’re replacing either the upper or lower radiator hose (steps cover both).

Difficulty Level: Beginner | Estimated Time: 1.0-2.0 hours

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⚠️ Safety & Precautions

• ⚠️ Never open the radiator/surge tank cap on a hot engine—hot coolant can spray out and burn you.
• ⚠️ Support the van with jack stands if you raise it—never rely on a floor jack alone.
• ⚠️ Keep hands/tools clear of the mechanical fan—only work with the engine OFF.
• ⚠️ Coolant is toxic—catch it in a drain pan and clean spills immediately.
• ✅ Battery disconnect is not required for this job.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Drain pan (at least 3-gallon)
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• Flat-blade screwdriver
• 1/4" drive ratchet
• 8mm socket
• 10mm socket
• Hose clamp pliers (specialty)
• Pick tool
• Razor blade scraper
• Shop rags
• Funnel
• Torque wrench (inch-pound)

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Upper radiator hose - Qty: 1
• Lower radiator hose - Qty: 1
• Hose clamps - Qty: 2
• DEX-COOL coolant - Qty: 2-4 gallons
• Distilled water - Qty: 1-2 gallons

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📋 Before You Begin

• Park on level ground, set the parking brake, and place wheel chocks behind the rear wheels.
• Let the engine cool completely (best is overnight).
• Set the HVAC to Heat later during bleeding (this opens the heater circuit so trapped air can escape).
• If you raise the front for access, lift with a floor jack and support with jack stands under the frame.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Relieve any leftover pressure (engine cold)

• Place nitrile gloves and safety glasses on.
• Slowly loosen the coolant cap (surge tank/radiator fill) by hand to release any pressure, then remove it.

Step 2: Drain coolant to below the hose level

• Position a drain pan (at least 3-gallon) under the radiator drain area.
• Open the radiator drain (petcock) slowly (use a flat-blade screwdriver only if needed).
• Drain until the coolant level is below the hose you’re replacing, then close the drain.
• Tip: Draining less keeps the mess smaller.

Step 3: Make room to access the hose

• If the air intake duct blocks access, loosen the clamps using an 8mm socket with a 1/4" drive ratchet, then move the duct aside.
• If needed, remove small covers/brackets using a 10mm socket.

Step 4: Remove the hose clamps

• If you have spring clamps, squeeze them with hose clamp pliers (specialty) (these lock onto the clamp so your hands don’t slip), then slide the clamp back on the hose.
• If you have worm-gear clamps (screw type), loosen them with a flat-blade screwdriver or 8mm socket, then slide the clamp back.

Step 5: Remove the old hose (upper or lower)

• Twist the hose by hand to break it free from the fitting, then pull it off.
• If it’s stuck, carefully work around the edge with a pick tool to break the seal (don’t gouge the radiator neck).
• If the hose will not come off, use a razor blade scraper to slit the hose lengthwise near the end, then peel it off carefully.
• Tip: Don’t pry hard on plastic radiator necks.

Step 6: Clean and inspect the hose fittings

• Wipe the radiator neck and engine/water pump neck with shop rags.
• Lightly clean stubborn residue with a razor blade scraper (gentle pressure).
• Inspect for cracks, heavy corrosion, or a damaged “bead” on the neck (the raised ridge that helps the hose stay on). If damaged, don’t reassemble until the part is repaired.

Step 7: Install the new radiator hose

• Slide the new clamp(s) onto the new hose before installing the hose.
• Push the hose fully onto the fitting until it seats past the bead/stop.
• Position the clamp behind the bead on the fitting.
• If using worm-gear clamps, tighten with an 8mm socket and 1/4" drive ratchet, then final tighten with a torque wrench (inch-pound): Torque to 35-45 in-lb (4-5 N·m).
• If using spring clamps, reinstall using hose clamp pliers (specialty) (no torque spec for spring clamps).

Step 8: Reinstall removed components

• Reinstall the air intake duct and tighten clamps using an 8mm socket and 1/4" drive ratchet.
• Reinstall any brackets/covers using a 10mm socket.

Step 9: Refill coolant

• Place a funnel in the surge tank/fill point.
• Refill with a 50/50 mix of DEX-COOL coolant and distilled water (unless you bought pre-mixed 50/50 coolant).
• Fill to the “COLD” mark (or just below the neck if your tank design differs).

Step 10: Bleed air and check for leaks

• Start the engine and let it idle.
• Turn the heater to full HOT and fan on medium.
• Watch the coolant level; add as needed with a funnel.
• As the engine warms up, carefully feel for heat from the vents (this helps confirm coolant is circulating through the heater core).
• Shut the engine off if you see dripping or spraying at the hose ends; fix clamp position/tightness.
• Let it reach normal operating temperature, then shut off and allow it to cool completely before topping off to the “COLD” mark.

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✅ After Repair

• Recheck coolant level after the first full heat-soak drive cycle (drive, cool completely, then check).
• Inspect both ends of the new hose for seepage and re-check clamp position.
• Look under the van for any coolant drips the next morning.
• Dispose of old coolant properly (most local parts stores accept used coolant).

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💰 DIY vs Shop Cost

Shop Cost: $250-$550 (parts + labor)

DIY Cost: $40-$140 (parts only)

You Save: $210-$410 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.0-2.0 hours.

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🎯 Ready to get started?

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