Home » GM 6.5 » GM/Detroit 6.5L – RADIATOR REPAIR PROCEDURES

GM/Detroit 6.5L – RADIATOR REPAIR PROCEDURES

The aluminum-plastic radiator can be repaired. The following components can be replaced:
• Core
• Tanks and gaskets
• Oil coolers and gaskets
• Drain cock and gasket

The tanks cannot be repaired if broken or cracked. The radiator core can be replaced and the new core used with the original tanks and oil cooler.

PRECAUTIONS
As with all cooling system service, take measures to prevent personal injury and damage to the system.

CAUTION: To help avoid being burned, do not remove the radiator cap w hile the engine and ra d ia to r are h o t. S c a ld in g flu id and steam can be blow n ou t under pressure if the cap is taken o ff too soon.

NOTICE : DO NOT USE “BOIL OUT ” TANKS OR WATS. Common service methods may destroy an aluminum radiator: Do not use caustic or lye cleaning solutions for alumi­num radiators. USE CLEAN WATER WHEN SERVICING ALUMINUM RADIATORS.

• Do not open the hood if you can see or hear steam or coolant escaping from the engine compartment.
• Do not remove the radiator cap if the radiator feels warm.
• Do not remove the radiator cap or coolant recovery cap if the coolant in the recovery tank looks like it is boiling.
• Wear eye protection.
• Wear gloves to protect your hands against exces­ sive heat of the effects of chemicals on your skin.
• Prevent dirt and water from entering the transmis­sion oil cooler.
• Do not use boil-out vats or other tanks that have been used for copper and brass radiators. The flux, acid, and caustic cleaners in these tanks will attack the aluminum and cause radiator failure. Use a separate test tank containing clean water for ser­vicing aluminum/plastic radiators.

NOTICE : Never use shop air to pressure test radiators that Is not regulated at 138’kPa (20 psi). Pressures over 138 k Pa (20 psi) will damage the radiator.

SPECIAL PREPARATION
For damaged areas between the cooling fins, it may be necessary to remove some of the fins. Do not remove more fins than necessary. Usually 6 mm (1/4 inch) beyond the leak or damaged area is enough to make an effective repair (figure 14).

TUBE BLOCKING
If a tube is severely damaged, it can be blocked off (figure 15).

NOTICE : Do not block off more than two tubes in a radiator. Blocking off more than two tubes will significantly reduce the cool­ing capacity of the system.

Cut the tube off 6 mm (1/4 inch) from the header and pinch shut before it is cleaned and sealed. Refer to “General Core Repair.”

HEADER REPAIR
If the header or a tube near the header requires a repair, the side tank does not have to be removed. A wet cloth can be placed against the side tank where the repair has to be made (figure 16). The side tank can also be submerged in a tank of water up to the header (figure 17).

NOTICE: One o f these procedures m ust be used when repairs are made on o r near the header to prevent damage to the tank o r gas­ket.

GENERAL CORE REPAIR
Preparation of the repair area surface cannot be over-emphasized. If the leak area surface is not clean, the repair materials will not stick to the surface.

1. Position the core so the repair is accessible.
2. Apply a wet cloth if you are working near the plastic tanks or the joints between the core tubes and header (figure 16), or submerge the tank in water (figure 17).
3. Heat the repair area slightly with a small torch or heat gun to be sure it is dry. Do not use a blow torch.
4. Brush the area to be repaired with the small steel brush that is supplied in the kit and blow dust away from the repair area (figure 18).

5. Open the tube of primer, using the spurred cap or a pin, and apply primer to the repair area only. Use of the primer produces a stronger repair. Do not heat the primer.

CAUTION: The primer contains trichloroethane. It could be harmful or fatal if swallowed. If swallowed, get medical atten­tion. Use with adequate ventilation. In case of eye contact, flush with water and get medical attention. In case of body contact, wash with soap and water. Do not mix the primer with water.

6. Scrub the repair area with a cotton swab until a fresh swab stays clean (figure 19). The clear, yel­low-brown coating does not have to be removed.
7. Heat the repair area with a heat gun or by moving the torch in a circular pattern (figure 20). Use a soft, small, blue flame (like a gas stove flame).

8. Withdraw the torch and rub the adhesive stick on the repair area (figure 21). The adhesive will flow at a temperature of approximately 260°C (500T). If the stick doesn’t melt, remove it and re-apply the heat. Do not heat the stick with a flame. High heat will burn and char the adhesive.
9. Continue heating until the adhesive flows and wets the entire repair area and fills the joint. If a hole is in the center of a tube, heat the tube and let the hot surface melt and puli in the adhesive. The force of the flame or heat gun will also tend to guide the adhesive toward the hole. For leaks between a tube and header, flow the adhesive around the tube and header joint with the tank installed.
10. Heat the repair area until the adhesive is bubble-free and smooth, with a light yellow color. Cur­ing is not required.
11. Test the radiator for leaks when cool. If the repair area still leaks, reheat it gently to dry it. Heat and reflow the adhesive or apply more as necessary to repair the leak.

TANK GASKET LEAK REPAIR
Tank gasket leaks can be mistaken for tank or header leaks. If a plastic tank leaks from the header joint gas­ket, tighten the clinch tabs with locking-type pliers or with BT 8260 Radiator Core Remover/Installer (figure 22). If this method doesn’t seal the leak, remove the tank for further inspection.

1. Pry open the clinch tabs, except those under the inlet, outlet, and filler necks, using BT 8260 Radia­tor Core Remover/ Installer (figure 23) or a screw­ driver (figure 25). Lift the tabs only enough to allow removal.

NOTICE : Do not over bend the tabs. Over bending could result in breakage. If there are more than three tabs broken on one side of the header, or more than two adjacent tabs together, replace the core.

2. Lift the tank and slide it out from under the remain­ing clinched tab. You may have to tap the tank with your hand to dislodge the gasket. Lift the remaining tab(s) with pliers.
3. Remove the gasket.
4. Clean the header and gasket groove of all dirt and old rubber.
5. Clean the sealing edge of the plastic tank.
6. Examine the header gasket and surface and tank flange for evidence of leakage. Clean or repair the surface to remove dirt, burrs, and bumps.
7. Remove the oil cooler, if equipped, and install it in the new tank.
8. Dip or coat the new tank gasket in engine coolant and position it on the header surface. The coolant helps hold the gasket in place.
9. Position the tank and gasket to the header. Clamp it in place and secure it by bending four clinch tabs as shown in figure 25.

10. Clamp the remaining clinch tabs around the header
using the clinching tool or pliers following the clinching sequence in figure 26.

Important
• Tighten the clinch tabs starting at the center and working out to the ends.
11. Replace the core if there are more than three tabs broken on one side or two adjacent tabs broken.
12. Install the drain cock, if removed.
13. Test the radiator.

OIL COOLER GASKET REPLACEMENT
Remove the outlet tank to replace the oil cooler. The oil cooler gaskets can be replaced without removing the tank.

Remove or Disconnect (Figure 27)
1. Radiator and lay it on a flat surface.
2. Bottom oil cooler nut and loosen the top nut.
3. Press the oil cooler into the hole and remove the gasket using a small hook (figure 27).
4. Blow-dry all surfaces on the tank and oil cooler.

Install or Connect (Figure 27)
1. New gasket without lubrication.
• Be sure it is seated properly inside the tip of the fitting.
• Reach into the oil cooler and push it into posi­tion against the tank.
2. Loosely assemble the oil cooler nut.
3. Replace the other gasket by following the same procedure.
4. Oil cooler huts.

• Engine oil cooler nuts to 20 N-m (15 Ibs. ft.).
• Transmission oil cooler nuts to 27 N.m (20 Ibs. ft).
• Do not overtighten.
5. Leak test.

OIL COOLER REPLACEMENT

Remove or Disconnect (Figure 9)
1. Side tank or from the radiator.
2. Nuts from the oil cooler fitting.
3. Oil cooler and/or gaskets.
4. Rubber gaskets from the oil cooler.

Clean
Oil cooler gasket areas.

Install or Connect (Figure 10)
1. Rubber gaskets to the oil cooler.
2. Oil cooler to the side tank.
• Do not loosen or misalign the gaskets.
3. Retaining nuts.

Tighten
• Transmission oil cooler nuts to 27 N-m (20 Ibs. ft.).
• Engine oil cooler nuts (117) to 20 N.m (15 Ibs. ft.).
4. Side tank to the radiator.
5. Leak test.

RECORE
If the radiator core is damaged beyond repair and the other parts are serviceable, install the original inlet and outlet tanks, oil cooler, radiator cap, and drain valve, along with the new core and new gaskets.

 

Leave a Reply

Your email address will not be published. Required fields are marked *