Abstract:
A brake bleed tool includes a pliable plastic tube which sealingly engages a bleed fitting. A bleed wrench coaxially slides along the tool to engage the bleed fitting. The bleed wrench includes a socket end for engaging the bleed fitting at one end and a winged end at the opposite end which is used to loosen and tighten the bleed fitting.

Description:
FIELD OF THE INVENTION 
     The present invention relates to tools used for bleeding a brake system. More particularly, the present invention relates to a brake bleed tool which simplifies the bleeding process while eliminating the leaking of brake fluid into the surrounding environment during the bleeding process. 
     BACKGROUND OF THE INVENTION 
     Hydraulic brake systems work because of the non-compressability of the hydraulic fluid within the systems. Thus, it is necessary to remove all gas such as air from the braking system. With gas or air in one or more of the brake lines, considerable effort is spent first compressing the air before any movement of the braking components occur. This presence of gas or air causes the brake pedal to be spongy, i.e., the brake pedal goes part way down without noticeable effort because air in the hydraulic line is being compressed. 
     The process for removing gas or air from the brake system is known as bleeding the brake system. There are several methods for bleeding a brake system for a motor vehicle. When bleeding the brake system at an assembly plant, a vacuum evacuation and brake fluid fill system is utilized. The vacuum evaluation and brake fluid fill system is mounted to a filler tube of the master cylinder of the brake system and it has a controller for directing the operation of the system first to evacuate the brake system and then pressure fill the brake system with brake fluid. In doing so, this method results in using a system which is expensive, cumbersome and needs a pressure and vacuum system. 
     When bleeding the brake in the after market, one method involves the use of a bleeder ball system. The bleeder ball system includes a spherical ball filled with brake fluid and a hose to attach the ball to a fluid reservoir of the master cylinder of the brake system. The bleeder ball system is connected to a constant source of air pressure to push air bubbles from the brake system as a fitting or bleeder tube is opened. In so doing, this method results in using a system which is relatively expensive, messy and needs a constant air pressure source. 
     The simplest and least costly method of bleeding the brake system in the after market is to open bleed ports or fittings in the brake system and then apply the brakes by pushing the brake pedal to the floor. While the brake pedal is being depressed, the ports or fittings are left open to allow brake fluid and trapped air to bleed out of the brake system. While keeping the brake pedal depressed, the bleeding ports or fittings are closed and then the brake pedal is released which allows brake fluid in the master cylinder reservoir to enter the brake lines replacing the fluid and trapped air that was bled out of the brake system. This method is somewhat time consuming and can result in excess brake fluid spilling over the work place, being messy, laborous and cumbersome and it is somewhat difficult to flush all air from the brake system. 
     One method used to contain the fluid being bled from the brake system is to sealingly attach a tube to the bleeding ports or fittings and then running this tube to some type of container to contain the bled fluid. While the use of this tube connection has helped to improve the cleanliness of the bleeding process, the use of the tube can result in the increased difficulty in opening and closing the bleeding port or fitting at the appropriate time. Thus, there is a need in the art for a bleeding system which can improve the cleanliness of the process without interfering with the bleeding process. 
     SUMMARY OF THE INVENTION 
     The present invention provides the art with a bleeding system which composes a bleeding tube which is designed to sealingly engage the bleeding port or fitting and a wrench coaxially surrounding the bleeding tube which is utilized to loosen and tighten the bleeding port or fitting. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
     FIG. 1 schematically illustrates a vehicle incorporating a hydraulic braking system; 
     FIG. 2 illustrates one of the wheel assemblies for the vehicle shown in FIG. 1; 
     FIG. 3 illustrates the brake bleed tool in accordance with the present invention; 
     FIG. 4 illustrates the brake bleed tool in accordance with the present invention prior to the tube of the brake bleed tool engaging the bleed fitting of the hydraulic brake system; and 
     FIG. 5 illustrates the brake bleed tool of the present invention in engagement with the bleed fitting of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
     Referring now to the drawings in which like reference numerals designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a vehicle incorporating a hydraulic brake system and which is designated generally by the reference numeral  10 . Vehicle  10  comprises a vehicle body (not shown) supported by four wheels  14  through a front suspension  16  and a rear suspension  18 . A hydraulic brake system  20  is designed to be activated by the operator of vehicle  10  in order to stop vehicle  10  by placing resistance to rotation onto wheels  14 . 
     Hydraulic brake system  20  comprises a master cylinder  22 , a plurality of slave cylinders  24 , brake lines  26  and a plurality of braking mechanisms  28 . Master cylinder  22  is typically mounted on a firewall  30  of vehicle  10  and it is operated using a brake pedal (not shown) as is well known in the art. The operation of master cylinder  22  by the brake pedal may or may not be through a power assist system which is typically a vacuum assist system. A slave cylinder  24  is positioned at each wheel  14  and each slave cylinder  24  is attached to master cylinder  22  through brake lines  26 . Each slave cylinder  24  is mechanically interconnected to a respective braking mechanism  28 . Braking mechanism  28  is typically a disc brake or a drum brake and it is utilized to impede the rotational motion of each wheel  14  through friction as is well known in the art. 
     In operation, when master cylinder  22  is activated by the operator using the brake pedal, hydraulic fluid in master cylinder  22  is pushed from master cylinder  22  to each slave cylinder  24  through brake lines  26 . A brake fluid reservoir  32  associated with master cylinder  22  ensures that only hydraulic brake fluid and not air is allowed into master cylinder  22 , slave cylinders  24  and brake lines  26 . 
     When hydraulic brake system  20 , wheels  14  or other portions of vehicle  10  are serviced, it may become necessary to dismantle or otherwise unseal hydraulic brake system  20 . It then becomes necessary to bleed brake system  20  during reassembly to ensure that all air within master cylinder  22 , slave cylinders  24  and fluid lines  26  has been removed. When one of the more sophisticated and expensive systems are not available, manual bleeding of brake system  20  is required. This manual bleeding of braking system  20  is accomplished by utilization of bleed valves  40  which are located on each of slave cylinders  24 . Typically the bleed valve  40  associated with the slave cylinder  24  associated with the wheel  14  furthest from master cylinder  22  is bled first. This is accomplished by opening bleed valve  40 , depressing the brake valve to allow a mixture of air and hydraulic fluid to flow through bleed valve  40 , closing bleed valve  40  and then releasing the brake pedal to replace the fluid in the system from reservoir  32 . This process is repeated until only hydraulic fluid flows through bleed valve  40  during the depressing of the brake pedal. This procedure is then completed for each wheel  14  moving towards the next wheel  14  furthest from master cylinder  22  until all four wheels  14  have been bled. 
     Referring now to FIGS. 3-5, the present invention provides a brake bleeding tool  50  which assists in the manual bleeding of brake system  20 . Brake bleeding tool  50  comprises a plastic tube  52  and a bleed wrench  54 . Tube  52  is manufactured from a material that is compatible with the brake fluid used by braking system  20 . Tube  52  is of sufficient length that it can reach between each of wheels  14  and a container (not shown) for holding the discarded hydraulic fluid from brake system  20 . Typically, bleed valve  40  includes a head  60  having a frusto-conical shaped end  62 , a relief section  64  and a hexagonal fastening end  66 . Tube  52  is manufactured from a pliable plastic which expands as it is pushed over frusto-conical shaped end  62  and then relaxes into relief section  64  to provide a seal between tube  52  and bleed valve  40  as shown in FIG.  4 . 
     Bleed wrench  54  includes a sockethead end  70 , a spacer tube  72  and a winged end  74 . Tube  52  extends through sockethead end  70 , spacer tube  72  and winged end  74  as is shown in FIG.  3 . Once tube  52  has been attached to bleed valve  40 , bleed wrench  54  is slid along tube  52  until sockethead end  70  engages hexagonal fastening end  66 . Bleed valve  40  can be loosened (opened) and tightened (closed) by rotating bleed valve  40  using winged end  74  to apply the necessary torque. Thus, as the brake pedal is pressed and released, bleed valve  40  can be easily opened and closed at the appropriate time to bleed brake system  20 . In addition, as brake fluid is released through bleed valve  40 , it is easily and safely transported to an appropriate container avoiding the spilling of the hydraulic fluid. 
     The present invention thus provides a simple low cost solution to the problems associated with manual bleeding of a brake system. By having a series of brake bleed tools  50  of various sizes available, a mechanic can quickly and easily bleed the brake system for any vehicle. 
     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.