mfquinn

I need some help please. I have a C6 that I have done brake bleeds on at least 30-40 times. So my friend has a 1992 that had brake fluid that was nasty! Being the nice guy I am I told him I would flush his brake fluid. OK, the brakes were working fine before I touched them. I sucked out all the old nasty brake fluid and filled it with fresh fluid. (On my C6 it is just one single brake fluid reservior) I then hooked up my Motiv bleeder and pumped up the pressure. I started at the rear drivers side, then rear passenger side opening the bleeder screws and bleeding each caliper until nice clean fluid was coming out and no air bubbles. I then unhooked the Motiv and topped off the reservoir with more fresh fluid and hooked the system up and started at the passenger front and then the drivers front. Same thing I have done over and over and over on my C6. When done, brake light is on and no brake peddle pressure. Right to the floor. I may have come close to running out of fluid in the reservoir on the last caliper (drivers side front).

The brake reservoir is different then on my car as it seems to have two seperate parts (see the picture below). I can see dirty fluid in the front part but have no clue how you get to that part. I am also not sure if it is that part that feeds the rear line or not.

So, please tell me what I did wrong. This was my first time with a C4 so I must have missed something. I am very embarrased with this. Help please

93Rubie

If you ran the fluid too low you will need to bleed the ABS Hydraulic control unit, it is in the rear compartment behind the drivers seat. The rubber tube pictured in your photo is the prime tube for the unit.

The bleeder in on the unit, get some line and a jar and some rags it is gona get messy.

jaa1992

OK, don't panic.

Can you find a helper to manually bleed the brakes?
A second pass with a helper doing the pump pedal smothly until hard, while helper maintains pressure on pad crack the bleeder. Close bleeder and pump till hard. Repeat 3 - 6 times at each caliper.

My flush procedure on my 92 uses a vaccum bleeder and a helper.
First pass with the vaccum bleeder, second pass using a helper.
I do pass rear, driver rear, pass front, pass rear - its a little different in the FSM, but this has worked for me for 5 years so I'll stick with it.

FYI - this will also bleed the ABS - there is no way to cycle the pumps using a Tech 1.

pcolt94

You probably got air into the master and if you did, by just filling the reservoir is never going to get the air out. Remove the master and bench bleed it, then reinstall. Do a normal bleed on the brakes maintaining fluid in the master.

There is also a possibility if it did run dry, the proportion valve might be out of position and not centered. I would just give that a quick check before bench bleeding.

The ABS requires no special procedure to bled it. If there is air in it, it will just bleed thru. I have replaced the entire ABS unit and just did a normal bleed