Unless the water system for the heat exchanger is sealed, debris may enter the water. Examples of debris are leaves, twigs, feathers, etc. Debris in the water will reduce the efficiency of the heat exchanger. This can result in excessive water temperatures that may require an engine shutdown. Preventing debris from entering the water and/or filtering the water will reduce the need for cleaning.
The quality of the water can also affect the performance of the heat exchanger. Buildup such as sediment and scale reduces the heat transfer characteristics of the plates. The pressure differential of fluids that flow through the heat exchanger is increased. Corrosion can occur beneath the buildup. The buildup can result from sources that are organic and/or inorganic.
The quality of the water can be monitored with water analysis. Treatment of the water can help to reduce the buildup. If it is not practical to treat the water, experience can help to determine a schedule for cleaning the heat exchanger. Water analysis and analysis of the buildup will help to determine the method for cleaning.
The combination of these two factors indicate that the heat exchanger requires cleaning:
- Inability of the heat exchanger to maintain the temperatures that are desired
- Increased pressure differential of the fluids that flow through the heat exchanger
Frequently record these parameters during operation:
- Aftercooler inlet water temperature
- Inlet manifold air temperature
- Jacket water temperature
- Pressure differential of the fluids that flow through the heat exchanger
Compare the data to previously recorded data. Clean the heat exchanger, if necessary.
Ensure that the machinery will not operate when this maintenance is performed. Attach a "DO NOT OPERATE" tag or similar warning tag to the controls before performing maintenance or repairs.
Cleaning the heat exchanger involves the following procedures:
- Draining the heat exchanger
- Disconnecting the coolant lines
- Opening the heat exchanger
- Cleaning the plates of the heat exchanger
- Closing the heat exchanger
- Connecting the coolant lines
- Filling the cooling system
 | |
| Illustration 1 | g00506207 |
Components of the heat exchanger (1) Carrying bar (2) Support column (3) Pressure plate (4) Support bar (5) Frame plate (6) Tightening bolts (7) Channel plates | |
Draining the Heat Exchanger
Note: See the engine's Operation and Maintenance Manual for information on the interval for changing the coolant.
 |
Pressurized System: Hot coolant can cause serious burns. To open the cooling system filler cap, stop the engine and wait until the cooling system components are cool. Loosen the cooling system pressure cap slowly in order to relieve the pressure. |
 |
- Prepare a suitable container for the coolant.
Note: If the heat exchanger is hot, wait until the temperature of the heat exchanger is reduced to approximately 40 °C (104 °F) before proceeding.
- Drain the heat exchanger. The method for draining depends on the equipment.
If the installation is equipped with shutoff valves for the water inlets and the outlets of the heat exchanger, shut off the valves.
If the installation does not have vent valves, remove the filler caps for the expansion tanks.
Note: For complete draining, all of the circuits of the heat exchanger must be ventilated.
- Open the valves for the aftercooler (1) , the cooling water (2) , and the jacket water (3) . Allow the coolant to drain.
After the coolant has drained, close the valves.
 | |
| Illustration 2 | g00505158 |
(1) Valve for the aftercooler (2) Valve for the cooling water (3) Valve for the jacket water | |
Disconnecting the Coolant Lines
- Disconnect coupling (1) by loosening bolt (6) . Remove the coupling and the bolt. It is not necessary to remove retainer (3) and gasket (4) .
 | |
| Illustration 3 | g00505324 |
(1) Couplings | |
Note: It is only necessary to disconnect the lines on the side of the heat exchanger with the carrying bar.
 | |
| Illustration 4 | g00505692 |
Detail of a typical coupling (1) Coupling (2) Sleeve (3) Retainer (4) Gasket (5) Tube (6) Bolt | |
- Note these characteristics of the tubes:
- Original position
- Orientation
- Depth of insertion
- Original position
- To enable the heat exchanger to be opened, move the tube out of the sleeve and away from the heat exchanger.
Opening the Heat Exchanger and Closing the Heat Exchanger
- Before opening the heat exchanger, measure dimension (A) . Record the measurement.
 | |
| Illustration 5 | g00505700 |
G3408 and G3412 heat exchanger Bolt tightening sequence and dimension (A) | |
 | |
| Illustration 6 | g00505810 |
G3508, G3512, and G3516 heat exchanger Bolt tightening sequence and dimension (A) | |
- Clean the bolt threads that are outside of the pressure plate with a steel wire brush. Coat the threads with a thin layer of multipurpose grease.
- Multiply dimension (A) by 1.05. Loosen the bolts to this length.
For G3408 and G3412 Engines, use the bolt tightening sequence from Illustration 5 .
For G3500 Engines, use the bolt tightening sequence from Illustration 6 .
- Remove bolts (1) and (2) .
- Multiply dimension (A) by 1.10. Loosen bolts (3) , (4) , (5) , and (6) to this length.
For G3408 and G3412 Engines, use the bolt tightening sequence from Illustration 5 .
For G3500 Engines, use the bolt tightening sequence from Illustration 6 .
To open the heat exchanger, remove the bolts in sequence.
- Lift the shroud upward in order to remove the shroud.
Note: For G3408 and G3412 Engines, the top bolt must be removed before the shroud can be removed.
- Mark the outside of the plates diagonally and/or number the plates in sequence. If the plates are removed, this is useful for reassembly.
 | |
| Illustration 7 | g00505816 |
Diagonally marked plates | |
- Clean the carrying bar. Slide the pressure plate to the support column.
- Only remove the plates if the material that is fouling the heat exchanger cannot be easily removed. Remove the plates, if necessary. Clean the plates. See the "Cleaning the Plates" topic.
Note: When possible, clean debris from the plates without removing the plates. See the "Cleaning the Plates" topic.
|
Bare hands can be injured by the plates of the heat exchanger. To help prevent hand injuries, always wear protective gloves when handling the plates. |
|
Note: Handle the channel plates carefully. Do not damage the gaskets.
- After the plates are clean, hang the plates.
Hang the number one plate against the frame plate. Orient the gaskets of the plates toward the frame plate.
- Inspect the sealing surfaces for cleanliness.
Inspect the gaskets for proper installation and for good condition. Ensure that the two tabs for each gasket are seated correctly. For instructions on installing the gaskets, refer to the literature that is supplied by the OEM of the heat exchanger.
Ensure that the channel plates are hanging in the correct order.
For large packages of plates, it may be necessary to tie off every 100 plates. Secure a strap around the number 100 plate and the frame plate. Hang another 100 plates. Secure the strap around the number 200 plate and the frame plate. Continue until all of the plates are hung.
When the plates are assembled correctly, the edges form a honeycomb pattern. Inspect the edge of the plate assembly for this condition. To ensure that the plates are hanging in the correct order, check the plates with the data that is provided by the OEM of the plates.
- Clean the carrying bar. Lubricate the sliding surfaces of the carrying bar with a thin layer of multipurpose grease.
- Press the plate assembly together.
- Install the shroud.
- Clean the bolts with a steel wire brush. Coat the threads of the bolts with a thin layer of multipurpose grease.
- Install bolts (3) , (4) , (5) , and (6) .
For G3408 and G3412 Engines, use the bolt tightening sequence from Illustration 5 .
For G3500 Engines, use the bolt tightening sequence from Illustration 6 .
Use a maximum of two full turns per nut. Tighten the nuts in sequential rotation. Tighten the bolts to the length that was determined in Step 5 .
- Install bolts (1) and (2) .
For G3408 and G3412 Engines, see Illustration 5 .
For G3500 Engines, see Illustration 6 .
Tighten all of the bolts until dimension (A) is achieved.
On adjacent bolts, do not exceed a difference of more than 2 mm (.079 inch) from dimension (A) .
On all of the bolts, do not exceed a difference of one percent from dimension (A) .
Do not exceed the maximum torques that are listed in Table 1 .
| Maximum Torque for Bolts With Washers | ||
| Thread Size | Torque | |
25.4 mm (1.00 inch) |
42 N·m (31 lb ft) |
|
28.58 mm (1.125 inch) |
84 N·m (62 lb ft) |
|
38.1 mm (1.50 inch) |
185 N·m (137 lb ft) |
|
Cleaning the Plates
| NOTICE |
|---|
Improper methods of cleaning will damage the plates. Do not scrape or scratch the plates. Do not use a wire brush for cleaning the plates. Use a brush with soft bristles. Be careful not to damage the gaskets. |
 | |
| Illustration 8 | g00505947 |
Use a brush with soft bristles for cleaning. Be careful not to damage the gaskets. (1) Gasket | |
Use running water and a brush with soft bristles for cleaning debris. Pressurized water at a maximum of 275 kPa (40 psi) may be used.
Dry the plates with a clean cloth.
Cleaning Buildup From the Plates
| NOTICE |
|---|
The use of some chemicals in cleaning solutions can cause corrosion and damage to some components. For the proper cleaning solutions, follow the recommendations that are provided by the OEM of the heat exchanger. |
Different types of buildup may require different cleaning solutions. To determine the cause of the buildup, obtain an analysis of the material and the water. Consult the OEM of the heat exchanger in order to determine the proper method of cleaning to use.
Connecting the Coolant Lines
|
During operation, the fluid in the lines of the cooling system is hot and pressurized. A rupture of the coupling could cause parts and hot fluid to be expelled. Improper selection, installation, or use of the coupling could result in property damage, personal injury, or death. Install couplings that are proper for the application according to the instructions. |
|
| | |
| Illustration 9 | g00505692 |
Detail of a typical coupling (1) Coupling (2) Sleeve (3) Retainer (4) Gasket (5) Tube (6) Bolt | |
- Ensure that gasket (4) is inserted to the proper length over tube (5) .
- Place the tube in the original position. Orient sleeve (2) with gasket (4) and retainer (3) . See Illustration 9 .
- Place the coupling over the retainer, the sleeve, and the gasket.
- Tighten bolt (6) to the torque that is correct for the size of the coupling. Refer to the engineering drawing of the water lines group.
Filling the Cooling System
| NOTICE |
|---|
Only use coolant/antifreeze mixtures that are recommended by the Operation and Maintenance Manual for the engine. Failure to do so can cause damage to the engine and the equipment. |
| NOTICE |
|---|
Never use water alone without Supplemental Coolant Additives (SCA) or without inhibited coolant. Water alone is corrosive at engine operating temperatures. Water alone does not provide adequate protection against boiling or freezing. |
- Remove the filler caps for the expansion tanks.
- Vent the aftercooler circuit. Open the vent valve or remove the vent plug.
For G3408 and G3412 Engines, see Illustration 10 .
For G3500 Engines, see Illustration 11 .
| NOTICE |
|---|
The vent valve or vent plug for the aftercooler must be opened in order to allow the aftercooler system to fill properly. Failure to do this will cause an air lock which will result in damage to the engine. Open the vent for the aftercooler in order to allow the system to fill properly. |
 | |
| Illustration 10 | g00520082 |
Top view of the vent valve for the aftercooler on G3408 and G3412 Engines | |
 | |
| Illustration 11 | g00520081 |
Vent plug for the aftercooler on G3500 Engines | |
- Add the proper coolant mixture into the jacket water and aftercooler cooling systems.
When the coolant flows from the vent for the aftercooler, close the vent. Shut the vent valve or install the vent plug.
| NOTICE |
|---|
Fill the cooling system no faster than 19 L (5 US gal) per minute to avoid air locks. |
- Do not install the filler caps for the expansion tanks. Start the engine.
Operate the engine in order to purge air from the cavities of the engine block. Allow the coolant to warm and allow the coolant level to stabilize. Inspect the cooling system for leaks and for proper operating temperature.
- Stop the engine. Top off the expansion tanks. Install the filler caps.