Brake bleeding issue
#1
Brake bleeding issue
Admittedly this is not specifically for my Cobalt, but I figured it's applicable to all cars and this seemed the best place for it.
On Saturday I replaced the brake booster in my Tiguan. Everything went as well as I expected; however, when I test drove it I noticed the brakes were extremely stiff. I also noticed that when the trans was in "park" it acted totally normal. Back to "drive" and it's like there's no booster. The brakes themselves work great, just no or little boost. I think the brakes are activating before the booster has a chance to provide boost.
I don't think the booster or vacuum pump can tell when the car is in park or drive, so I don't think the problem is vacuum-related. The two theories I have are: 1) the pushrod is not aligned in the master cylinder causing the cylinder to be actuated too early, or 2) I bled them with the parking brake on, and when I released the parking brake it added fluid/pressure into the lines.
I'm mostly wondering if the second theory is even possible? I would think that a fluctuation in fluid would just go into the reservoir. The caveat with that is that the brake pedal must be pushed in order to release the parking brake (it's an electric motor on the calipers). Either way I'm checking it all tonight.
On Saturday I replaced the brake booster in my Tiguan. Everything went as well as I expected; however, when I test drove it I noticed the brakes were extremely stiff. I also noticed that when the trans was in "park" it acted totally normal. Back to "drive" and it's like there's no booster. The brakes themselves work great, just no or little boost. I think the brakes are activating before the booster has a chance to provide boost.
I don't think the booster or vacuum pump can tell when the car is in park or drive, so I don't think the problem is vacuum-related. The two theories I have are: 1) the pushrod is not aligned in the master cylinder causing the cylinder to be actuated too early, or 2) I bled them with the parking brake on, and when I released the parking brake it added fluid/pressure into the lines.
I'm mostly wondering if the second theory is even possible? I would think that a fluctuation in fluid would just go into the reservoir. The caveat with that is that the brake pedal must be pushed in order to release the parking brake (it's an electric motor on the calipers). Either way I'm checking it all tonight.
#12
There is, it is for removing fluid or air from the abs pump. My dad mentioned he had some air in his Golf's brakes after bleeding forever, and I mentioned that procedure. He said he ran it till his leg was dead.
I tested it a little more and decided it's working just a little stiff. I'm not going to disassemble it.
I tested it a little more and decided it's working just a little stiff. I'm not going to disassemble it.
#13
Senior Member
iTrader: (6)
Get a pressure bleeder, best purchase I made. It would be better if the fluid would transfer from the pressure tank into the brake fluid reservoir better but it still makes things go quick. I've read you can modify the pressure bleeders to transfer the fluid better but I haven't made the modification to mine.