Method and apparatus for servicing engine cooling systems

Abstract

Method and apparatus, for servicing engine cooling systems, including a service inlet, a vacuum pump, a two-way solenoid interposed between the vacuum pump and the service inlet, a service outlet, a disposal hose, a new fluid tank, a pressure pump interposed between the service outlet and the new fluid tank, a three-way solenoid interposed between the service outlet and the two-way, solenoid, a low-level trigger mechanism, a flow control relief valve and other elements to enhance various modes of operation. The apparatus is capable of performing various operations, including closed-loop fluid cycle, fluid vacuum, fluid top-off, fluid exchange and fluid flow control.

What is claimed is:  
     
       1. A service apparatus for servicing a system, said apparatus comprising: 
       a service inlet  
       a first pump;  
       a service outlet;  
       a fluid tank;  
       a second pump interposed between said service outlet and said fluid tank; and  
       a second solenoid interposed between said service outlet and said first solenoid;  
       wherein an inlet of said fist solenoid is connected to an inlet of said second solenoid, without said service apparatus being connected to said system.  
     
     
       2. The service apparatus of  claim 1  further comprising a low-level fluid trigger causing said second pump to halt when said second fluid in said tank reaches a predetermined low-level. 
     
     
       3. The service apparatus of  claim 1  further comprising a first check valve interposed between said service outlet and said second solenoid. 
     
     
       4. The service apparatus of  claim 1  further comprising a filter interposed between said service inlet at one end and said inlets of said first and second solenoids at another end. 
     
     
       5. The service apparatus of  claim 1  further comprising a fluid relief valve coupled to said second pump at one end and coupled to said service outlet at another end. 
     
     
       6. The service apparatus of  claim 1  further comprising a pressure relief valve coupled b said second pump at one end and coupled to an inlet of said tank at another end wherein said pressure relief valve opens in response to system pressure. 
     
     
       7. The service apparatus of  claim 1  further comprising a find relief valve coupled to said second pump at one end and coupled to a first check valve at another end, wherein said first check valve is coupled on said service outlet. 
     
     
       8. The service apparatus of  claim 1  further comprising a check valve coupled to an output of said first pump. 
     
     
       9. The service apparatus of  claim 1  further comprising a pressure gauge interposed between said second pump and said service outlet. 
     
     
       10. The service apparatus of  claim 1 , wherein said second solenoid is coupled at a first outlet to said service outlet, at a second outlet to an output of said first pump and at said inlet of said second solenoid in said service inlet. 
     
     
       11. A service apparatus for servicing a system said apparatus comprising: 
       a service inlet;  
       a first pump;  
       a first solenoid interposed between said first pump and said service inlet  
       a service outlet;  
       a fluid tank;  
       a second pump interposed between said service outlet and said fluid tank; and  
       a second solenoid interposed between said service outlet and said first solenoid;  
       wherein said second solenoid is a three-way solenoid coupled at a first outlet to said service outlet, at a second outlet to an output of said first pump and at an inlet of said second solenoid to said service inlet.  
     
     
       12. The service apparatus of  claim 11  further comprising a low-level fluid trigger causing said second pump to halt when said second fluid in said tank reaches a predetermined low-level, and causing said three-way solenoid to establish a fluid path between said service inlet and said service outlet such that system fluid cycles through said apparatus. 
     
     
       13. The service apparatus of  claim 11  further comprising a first check valve interposed between said service outlet and said second solenoid. 
     
     
       14. The service apparatus, of  claim 11  further comprising a filter interposed between said service inlet at one end and said inlet, of said first and second solenoids at another end. 
     
     
       15. The service apparatus of  claim 11  further comprising a fluid relief valve coupled to said second pump to one end and coupled to said service outlet at another end. 
     
     
       16. The service apparatus of  claim 11  further comprising a pressure relief valve coupled to said second pump at oft end and coupled to an inlet of said tank at another end, wherein said pressure relief valve opens in response to system pressure. 
     
     
       17. The service apparatus of  claim 11  further comprising a fluid relief valve coupled to said second pump at one end and coupled to a first check valve at another end, wherein said first check valve is coupled to said service outlet. 
     
     
       18. The service apparatus of  claim 11  further comprising a check valve coupled to an output of said first pump. 
     
     
       19. The service apparatus of  claim 11  further comprising a pressure gauge interposed between said second pump and said service outlet. 
     
     
       20. A method of servicing a system having an inlet and an outlet, said method comprising the steps of: 
       connecting a service inlet of a service apparatus to said system outlet;  
       connecting a service outlet of said apparatus to said system inlet; initiating a fluid-replacement process including the steps of:  
       pumping out a first fluid from said system through said system outlet and said service inlet; and  
       pumping in, simultaneously with said pumping out step, a second fluid from a second fluid tank to said system through said system  service outlet and said service  system inlet;  
       terminating said fluid-replacement process; and  
       cycling said second fluid, pumped into said system, through said apparatus, after said terminating step.  
     
     
       21. The method of  claim 20 , wherein in said step of cycling, said second fluid enters said apparatus through said service inlet and exits said apparatus through said service outlet back into said system. 
     
     
       22. The method of  claim 20  further comprising a step of cycling said first fluid through said apparatus prior to said step of pumping out said first fluid. 
     
     
       23. The method of  claim 20 , wherein in said terminating step, said pumping steps terminate when second fluid level in said second fluid tank reaches a predetermined low-level. 
     
     
       24. A service apparatus for servicing a system having an inlet and an outlet, said apparatus comprising: 
       a service inlet for receiving fluid from said system outlet;  
       a service outlet coupled to said service inlet and directing said fluid to said system inlet;  
       a filter; and  
       a solenoid;  
       wherein said fluid cycles through said service apparatus and said system, and wherein said filter is coupled at one end to said service inlet and at another end to a first end of said solenoid, and wherein a second end of said solenoid is coupled to said service outlet.  
     
     
       25. A service apparatus for servicing a system having an inlet and an outlet, said apparatus comprising: 
       a service inlet for receiving fluid from said system outlet;  
       a service outlet coupled to said service inlet and directing said fluid to said system inlet;  
       a filter; and  
       a solenoid;  
       wherein said fluid cycles through said service apparatus and said system, and wherein said filter is coupled at one end to said service inlet and at another end to a first end of said solenoid, a second end of said solenoid is coupled to one end of a check valve, and wherein another end of said check valve is coupled to said service outlet.