Abstract:
A method of refilling coolant from a fluid cooling system of an engine, where the fluid cooling system has a surge tank or pressure cap, includes the steps of sealingly connecting a storage tank of a coolant management tool to a drainage port of the cooling system, wherein the drainage port is located at the bottom of the fluid cooling system. The storage tank stores the coolant to refill the cooling system. The method includes installing a vacuum module to the surge tank or pressure cap. The method also includes the steps maintaining a vacuum while drawing at least a portion of the coolant from the storage tank up through the drainage port, up through the cooling system, and to a level just upstream of the vacuum module.

Description:
BACKGROUND 
       [0001]    Embodiments described herein relate generally to tools and methods for engine maintenance, and more particularly, to a tool and a method for draining and refilling a cooling system of an engine. 
         [0002]    Repair and maintenance of the engine periodically includes draining and refilling the coolant in the cooling system of an engine, such as in a vehicle, boat or stationary water-cooled engine. Typically, a petcock is located at the bottom of a radiator or radiator pipe of the cooling system. To drain the cooling system, the petcock is opened to allow the coolant to flow out of the cooling system under gravity. A cap at the top of the radiator or cooling system is also removed to allow air to enter the cooling system, so that a vacuum does not impede the flow of coolant out of the petcock. Alternatively, the cap of a radiator or cooling system is opened to allow the air to flow into the cooling system. 
         [0003]    After the repair or maintenance, if the coolant is not contaminated before or during the draining process, often the drained coolant is placed back into the cooling system. Technicians draining the coolant typically collect the coolant in a pan located beneath the petcock. In the pan, the coolant is open to contamination and is also susceptible to spilling. 
         [0004]    After the coolant is drained from the engine, the cooling system is re-filled with coolant. The petcock is closed and coolant is poured into a filler neck at the top of the engine or into the surge tank. Pouring the coolant back into the cooling system can be time consuming and can often lead to spilling and contamination. Also, because of the complexity of the cooling system, air can get trapped within the cooling system. Trapped air in the cooling system can cause damage to the EGR coolers. Additionally, trapped air can result in low coolant level fault codes and warnings, or even engine shut-down caused by an engine protection system at the vehicle&#39;s engine control unit. 
         [0005]    The conventional method to bleed the cooling system of the trapped air is to run the engine for a period of time to let the air escape the cooling system, and after the air has escaped, to add more coolant to the cooling system. Bleeding the cooling system is a time-consuming process. 
       SUMMARY 
       [0006]    A method of refilling coolant from a fluid cooling system of a engine, where the fluid cooling system has a surge tank or pressure cap, includes the steps of sealingly connecting a storage tank of a coolant management tool to a drainage port of the cooling system, wherein the drainage port is located at the bottom of the fluid cooling system. The storage tank stores the coolant to refill the cooling system. The method includes installing a vacuum module to the surge tank or pressure cap. The method also includes the steps maintaining a vacuum while drawing at least a portion of the coolant from the storage tank up through the drainage port, up through the cooling system, and to a level just upstream of the vacuum module. 
         [0007]    A method of refilling coolant to a fluid cooling system of an engine, where the fluid cooling system has a surge tank or pressure cap, includes the steps of sealingly connecting a storage tank of a coolant management tool to a drainage port of the cooling system. The drainage port is located on a lower surface of a radiator or at the lowest point of the cooling system. The storage tank stores the coolant to refill the cooling system. The method also includes the steps of installing a vacuum module to the surge tank or pressure cap, drawing at least a portion of the coolant from the storage tank up through the drainage port, up through the cooling system, and substantially up through the surge tank or pressure cap. The method further includes continuously evacuating air from the cooling system with the vacuum module until the coolant level is just beneath the vacuum module. 
         [0008]    A method of draining coolant from a fluid cooling system of an engine and refilling the coolant to the fluid cooling system, where the fluid cooling system has a surge tank or pressure cap, includes the step of sealingly connecting a storage tank of a coolant management tool to a drainage port of the cooling system. The drainage port is located at the bottom of the fluid cooling system. The method also includes the steps of installing a pressure module to the surge tank or pressure cap, applying a higher pressure to the cooling system from the pressure module, extracting under higher pressure at least a portion of the coolant from the cooling system into the storage tank, and replacing the pressure module with a vacuum module at the surge tank or pressure cap. The method also includes evacuating air from the cooling system with the vacuum module, and maintaining a vacuum while drawing at least a portion of the coolant from the storage tank up through the drainage port, and substantially up through the cooling system, and to a level just upstream of the vacuum module. 
         [0009]    As described above, the Tool and Method for Draining and Refilling a Cooling System provides a number of advantages, some of which have been described above and others of which are inherent in the invention. Also, modifications may be proposed to the Tool and Method for Draining and Refilling a Cooling System without departing from the teachings herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view of a tank-cart assembly of a coolant management tool. 
           [0011]      FIG. 2  is a perspective view of a cap adaptor of the coolant management tool. 
           [0012]      FIG. 3  is a front view of a vacuum module of the coolant management tool. 
           [0013]      FIG. 4  is a front view of a pressure module of the coolant management tool. 
           [0014]      FIG. 5  is a side view of a quick-connect fitting on a radiator and a mating quick-connect fitting on a hose. 
           [0015]      FIG. 6  is a front view of the pressure module attached to the cap adaptor of a surge tank. 
           [0016]      FIG. 7  is a side perspective view of the coolant management tool being used to refill coolant in a cooling system of a vehicle. 
           [0017]      FIG. 8  is a front view of the vacuum module attached to the cap adaptor of the surge tank. 
           [0018]      FIG. 9  is a top view of a three-way valve on a storage tank. 
           [0019]      FIG. 10  is a schematic of the coolant management tool attached to the engine cooling system. 
           [0020]      FIG. 11  is a flowchart of method steps for using the coolant management tool. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    Referring to  FIGS. 1-11 , a coolant management tool is indicated generally at  10 , and includes a tank-cart assembly  12 , a three-way valve  14 , and a hose  16 . The tank-cart assembly  12  has a cart  18  that may be provided with a plurality of wheels  20  at four corners of a cart platform  22 , however other configurations of carts are possible. A handle structure  24  may extend generally perpendicularly from the cart platform  22 . Optionally, an accessory storage basket  26  may be disposed on the handle structure  24  to store accessories of the coolant management tool  10 . 
         [0022]    A storage tank  28  is received on the cart platform  22  so that it is generally portable. The storage tank  28  is an enclosed container, and may be generally rectangular-prismatic and have an internal volume of about 20-gallons, however other configurations and volumes are possible. At a top surface  30 , the storage tank  28  has a cap  32  over a port for adding new coolant. 
         [0023]    Also at the top surface  30  of the storage tank  28  is the three-way valve  14 . The three-way valve  14  has three positions, a first “drain” position allowing coolant to flow into the storage tank  28 , a second “fill” position allowing coolant to flow out of the storage tank, and a third “closed” position where coolant cannot enter or leave the storage tank. In the fill position, the coolant is drawn through a hose  34 . A filter  35  may be disposed on the hose  34  between a one-way check valve  36  and the three-way valve  14  to filter the coolant. In the “drain” position, the coolant may enter the storage tank through a separate hose  38 . With the three-way valve  14  in the “drain” position, coolant cannot exit the storage tank  28 . 
         [0024]    At step 1, the coolant management tool  10  is connected to the cooling system  40 . The hose  16  extends from the three-way valve  14  and is connected to the cooling system  40  of an engine  42 . The engine  42  can be an engine in a vehicle, a boat, a stationary water-cooled engine, or any other engine having a cooling system  40 . To drain a full cooling system  40 , the coolant management tool  10  is connected to the cooling system  40  with a quick-connect fitting  46  on the end of the hose  16 . A corresponding quick-connect fitting  48  is disposed on a radiator  50  or on a lower radiator pipe at a bottom drainage port  51 . If the drainage port  51  of the radiator  50  has a petcock instead of a quick-connect fitting, the petcock can be replaced or retrofitted with the quick-connect fitting member. Alternatively, the drainage port  51  may be located on the cooling system  40  other than at the radiator  50  or radiator pipe. The drainage port  51  may be located anywhere in the cooling system  40  that is in a substantially downstream location in terms of the flow of coolant under gravity. The three-way valve  14  on the storage tank  28  is opened to “drain” position to drain the coolant into the storage tank at step 1A. 
         [0025]    At step 2, a pressure module  60  and a cap adaptor  54  are attached to a surge tank  52  of the vehicle  44 . The surge tank  52  is part of the cooling system  40  and is in upstream fluid communication with the radiator  50  in terms of the direction of flow of coolant under gravity. While the following description will reference a surge tank  52  because many cooling systems have a surge tank or expansion tank, it is possible that the cooling system  40  may not have a tank. In such cooling systems, such as those that employ a pressure cap or fill area, the “surge tank” as used herein refers to the uppermost area of the cooling system  40  (in terms of the direction of flow under gravity) in which coolant can be introduced to the system, whether or not there is a tank. 
         [0026]    The cap adaptor  54  attaches to the surge tank  52  (or uppermost area of the cooling system  40 ). The cap adaptor  54  has a quick-connect fitting  56  and provides a channel  58  for fluid flow. The pressure module  60  having a valve  61  and a regulator  62  is attached to the cap adaptor  54 . Either directly or through a hose  64 , the pressure module  60  can be attached to shop air, or some other source, through a shop air hose  66  at step 3, and the pressure module valve  61  is opened at step 3B. Shop air or other high pressure fluid (gas or air) is fluidly communicated to the pressure module  60  and through the channel  58  to the surge tank  52  of the cooling system  40 . The pressure module  60  regulates the shop air with the regulator  62  to apply pressure to the cooling system  40 . The regulator may be a non-adjustable 15 psi regulator. The pressure module may include a gauge  68  that indicates the pressure of the cooling system  40 . The pressure module may also include a pressure relief valve to vent the surge tank  52  and the cooling system  40 . The relief valve mimics the relief function of the cooling system pressure cap. 
         [0027]    At step 4, the coolant is extracted into the storage tank  28  under high pressure of about 15 psi, however other pressures are possible. The pressure module  60  is attached to the surge tank  52  through the cap adaptor  54 , and the pressure module valve  61  is opened. Using the shop air and the regulator  62 , the coolant is drained out of the engine and into the storage tank  28  through hose  38  under pressure. Depending on the capacity of the storage tank  28 , the storage tank may be filled partially or entirely. The coolant may be rapidly drained under pressure into the storage tank  28  in about 2-3 minutes, and since the storage tank  28  is an enclosed container, there may be no spills or contamination involved in the draining process. 
         [0028]    When the cooling system  40  is drained of the coolant, repairs can be conducted on the engine and cooling system at optional step 5. The pressure module valve is closed during repairs at optional step 5A. 
         [0029]    Before the cooling system  40  is re-filled with coolant, the pressure module  60  can be used to conduct a pressure test to test for leaks in the cooling system at step 6. A leak may be the result of a hose clamp or connection that is loose. With the pressure module  60  attached to the surge tank  52 , and with the three-way valve  14  on the storage tank  28  closed at step 6A, the valve  61  on the pressure module is opened at step 6B. Leaks are typically audible or located by the user by spraying the area with a bubble forming solution. Optionally, after the valve  61  on the pressure module  60  is opened, the valve can be subsequently closed at step 7A to perform a pressure decay test at step 7. 
         [0030]    To refill the coolant, the pressure module  60  is removed from the surge tank  52  and a vacuum module  70  is attached to the surge tank at step 8. The vacuum module  70  may include a valve  72  and a hose  74  extending from the valve to receive the shop air hose  66 . The three-way valve  14  on the storage tank  28  is turned to the “off” position, and the valve  72  of the vacuum module  70  is turned on at step 8A. The coolant management tool  10  pulls a vacuum on the cooling system  40 , which may cause a gauge  76  of the vacuum module to indicate a predetermined pressure of about 20-25″ Hg vacuum. 
         [0031]    Upon the gauge  76  indicating the predetermined pressure, the three-way valve  14  on the storage tank  28  is turned to the “fill” position at step 9A, the vacuum module  70  remains on, and coolant flows through the filter  35  into the cooling system  40  from the bottom drainage port  51 , up through the fluid cooling system  40 , and fills the surge tank  52 . In the “fill” position, draining cannot occur due to a one-way check valve  36  located on the hose  34 . 
         [0032]    Through the vacuum created by the vacuum module  70 , the coolant is drawn up into the engine cooling system  40  through the drainage port, from the bottom of the cooling system up into the surge tank  52  at step 9. The term “bottom” generally refers to a point on the cooling system  40  that has a low elevation when the vehicle is horizontal. The vacuum allows the coolant to flow up substantially or entirely through the cooling system  40 , countering gravity. The vacuum applied by the vacuum module  70  is continuously maintained until the level of the coolant drawn up through the bottom of the cooling system  40  is just upstream of the vacuum module  70 . The term “just upstream” of the vacuum module means that, in the direction of flow during refill of the coolant from the bottom up through the cooling system, the coolant stops short of reaching the vacuum module. In an embodiment with the surge tank  52 , the surge tank may be substantially or entirely filled with the coolant. If coolant exceeds the volume of the surge tank  52  or cooling system  40 , and if the coolant enters the vacuum module  70 , the coolant is vented out the hose  75 . The exhaust of the shop-air from the vacuum module  70  vents out the hose  75 . By continuously evacuating air with the vacuum module  70 , the vacuum is not terminated or degraded until the coolant level is refilled to just beneath the vacuum module. 
         [0033]    As the user refills the coolant into the cooling system  40 , the user watches the level of the coolant in the surge tank  52  at step 10, and the user turns the three-way valve  14  on the storage tank  28  to the “off” position at step 10A before air enters the cooling system. The user turns the vacuum module  70  off at step 10B as the coolant in the cooling system  40  reaches its capacity, just upstream of the vacuum module  70 . The surge tank  52  may have a “full” delineation on the surge tank to aid the user in seeing when the cooling system  40  is near capacity. The three-way valve  14  on the storage tank  28  is turned off by the user, the user removes the cap adaptor  54  and the vacuum module  70  from the surge tank  52 , and the user removes the quick-connect hose  16  from the drainage port  51  to disconnect the tool  10  at step 11. 
         [0034]    Portions of the coolant management tool  10 , such as the cap adapter  54 , the pressure module  60  and the vacuum module  70 , can be stored in the storage basket  26  when they are not in use. 
         [0035]    With the coolant management tool  10  and method of using, the likelihood of mixing coolant types is reduced. Also, the time to drain, pressure test, refill and bleed the cooling system is reduced. By pressure testing the cooling system before coolant is added or refilled, leaks are more easily corrected without spilling or loss of coolant. Air pockets in the cooling system are also reduced and may be eliminated, which protects the EGR coolers. Since the method is contained in closed containers and hoses, the likelihood of spilling or contaminating the coolant is reduced. 
         [0036]    While specific embodiments have been described in detail in the foregoing detailed description and illustrated in the accompanying drawings, those with ordinary skill in the art will appreciate that various permutations of the invention are possible without departing from the teachings disclosed herein. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalents thereof. Other advantages to a Tool and Method for Draining and Refilling a Cooling System may also be inherent in the invention, without having been described above.