Brake fluid change & bleeding

[Corvette-Pilot]

I just bought one of those Mite-Vac kits that you can check both pressue and vacuum. It also lets you bleed brake lines alone.

In the manual it mentions that some ABS systems you may need to release the pressure first. They recommend pumping the brakes 30-40 times.

Does this sound right?

I wanted to replace the brake fluid in the Vette (94) and my truck but now I'm not sure how to proceed??

 

[Tuna]

Howdy,

The requirement to bleed off pressure before bleeding the brakes is probably a turbo-charged car issue. This was a requirement on my old Grand National as the brakes had a nitrogen pressure bottle that provided the 'boost' or 'power' in the power brakes. With the engine off, you pumped the brakes a minimum of 10 times and the excess pressure was eliminated.

Unless your car is turbocharged or supercharged, you probably don't need to worry about this.

As for the actual bleeding, I found that installing "Speed Bleeders" was the easiest way to bleed the brakes.

With the Mite-Vac, make sure that you don't allow any air back in to the calipers. The check valves are supposed to do that for you, but watch them closely and use clear hoses to watch the flow of the fluid. And tighten the bleeder values before you disconnect the hose.

 

[mjlisz]

What about the ABS?

Hi,

On this subject, does anyone know if there is anything you need to do to the ABS system when bleeding? Somewhere I read about an ABS brake fluid reservoir or something.

Mike

 

[Magmotor]

Mike,
Here's some ABS info:

 

[jmccloud]

Corvette-Pilot

Most GM ABS systems require relieving the pressure by pumping the brake pedal 40-50 times with the key off (and leave it off until the brake work is complete). Unless the pressure is relieved, you probably won't be able to compress the caliper cylinder and pull the pads free of the rotor. I couldn't believe it the first time I read it either, but it works.
Good luck

 

[Corvette-Pilot]

Thanks guys for all the tips !
I would figure it couldn't hurt to do the pedal pumping just in case.
We'll see, not sure when I will get to this project just yet??