No brake pressure
Your complaint states that you see no air, is there fluid coming out of the left bleeder when bleeding the brakes? If you only see a few drops dribbling out, or nothing comes out at all...This can be a very difficult problem to solve. If this vehicle is a 1992 or later, it has rear antilock brakes, and if it is an ABS system, bleeding usually requires special equipment, and procedures. But there is something you can try. This takes quite a bit of time and patience, and a little bit of preparation. First you must realize that in the case of rear ABS, each rear brake has it's own fluid source, and plumbing from the ABS unit. If the obstruction is in the ABS unit none of the steps following will solve the problem, but you'll have to perform these steps to find out! DO NOT TOUCH THE BRAKE PEDAL UNTIL I INSTRUCT YOU TO HAVE AN ASSISTANT HELP YOU! USE PROPER PROTECTIVE EQUIPMENT! (Gloves, and eye protection, and protect your skin from exposure to brake fluid!) First we must know whether the flexible brake hose on the left rear is obstructed. The easiest way is to simply replace it, or if you don't want to start with a new part, you could disconnect it from the steel brake line that runs along the frame towards the rear of the car. (you don't have to remove it from the wheel cylinder first). Place a drip pan underneath the disconnected components. Now open the hood and remove the master cylinder cap. Make sure the brake fluid level is at the maximum height in the master cylinder. Now go back and look to see if there is any fluid leaking from the steel brake line. If there is not, then this is the point where patience is a virtue. There is air in the system all the way to the ABS unit. If the ABS unit is not obstructed or defective, fluid should flow by virtue of the force of gravity through the system and out of the end of the disconnected steel line, but if there is no fluid flow, it will take several minutes to possibly up to an hour and a half. If you have the patience to leave the car alone, maybe go to lunch, or to the auto parts store to shop for a while, gravity will do the bleeding for you. Once fluid begins to leak from the line, reconnect the brake hose and open the bleeder. Allow several more minutes for the wheel cylinder to fill and fluid to bleed out of the bleeder, then close the bleeder. Now do a complete bleed procedure using an assistant to pump the brakes while you finish bleeding any remaining residual air out. If you didn't get fluid from the bleeder, after you reconnected the hose, and after you waited long enough for the wheel cylinder to fill, then the brake hose is obstructed, and you will need a replacement brake hose. Once you are sure there is fluid flow, and no obstructions between the bleeder and the ABS unit, then you shouldbe able to obtain adequate pressure. If you can not get pressure, or fluid flow, you probably need to replace the ABS unit. There are additional procedures for ABS unit bleeding, but again, special equipment is required, so professional service is recommended.
Sep 20, 2008 |
1992 Oldsmobile Ninety Eight Regency