gravity bleeding /sjm abs delete line lock help
My setup is a 96z with the c5 brake upgrade with the pbr's and stock 96 rear z calipers. I replaced my master cylinder and bench bled it for about 45 minutes. I was using short movements when doing the bench bleeding. i got to a point that i could barely notice any bubbles. Then i put it back on the car and went and bled the four wheels with the pedal pump, hold, bleed, repeat method with my brother.
After doing that, i was rewarded with a pedal that went straight to the floor when we started the car.
So i looked around and did some research on here and got on gravity bleeding. So i gravity bled the front left by itself first with about 20oz of brake fluid. I just simply had it draining into a water bottle. while i did this, the proportioning valve was completely closed (clockwise all the way). I then started the car and noticed the pedal was significantly stiffer! I was all excited, so then I took the rear wheels off and gravity bled both the rears at the same time with about 20oz total on both sides just dripping into plastic bottles. I closed it all up and got the car back on the ground and drove it. The pedal is still significantly soft and I'm not getting it to get that super real nice firmness.
I'm wondering what else to try? I've been wrenching for many many years and this is the first time I've ever had this much crap with bleeding brakes. I'd like to believe i'm missing something obvious, but please let me know your thoughts. Thanks guys!!
So now waiting for a power bleeder to get that nice final bleed and things should be good!
Regarding the power bleeder, I am not personally a fan of them. Using a diaphragm bleeder is different than the bug sprayer types. You can aerate brake fluid with those bug sprayers as you pressurize the container.
A simple inexpensive alternative to the bug spray setups would be to purchase a new master cap and screwing a male compressor fitting onto the center of it. Since the cap is a direct replacement, it will just screw onto the master cylinder. Using LOW pressure via regulator adjustment will create the same effect as the bug sprayer...without the same aeration affect. You just need to make sure the master doesn't run dry. Typically you can bleed two wheels before refilling. When it starts running low, unscrew the cap and add fluid. Cost is probably 5-10.00 provided you already own an air compressor. Realistically, 32oz is way more than enough to completely flush the braking system. Most importantly, start with FRESH fluid minimizing mixing with old fluid as your dilution level is greater.
Using the two man method makes short work of bleeding the brakes aside of using a diaphragm bleeder. Gravity bleeding is too slow and isn’t as affective forced pressure methods.
A thought for you, maybe you should offer a 5 line set with the c5 lines up front and the rest of the rears on the lt1 setup. I can be your first customer :-)
Regarding the power bleeder, I am not personally a fan of them. Using a diaphragm bleeder is different than the bug sprayer types. You can aerate brake fluid with those bug sprayers as you pressurize the container.
A simple inexpensive alternative to the bug spray setups would be to purchase a new master cap and screwing a male compressor fitting onto the center of it. Since the cap is a direct replacement, it will just screw onto the master cylinder. Using LOW pressure via regulator adjustment will create the same effect as the bug sprayer...without the same aeration affect. You just need to make sure the master doesn't run dry. Typically you can bleed two wheels before refilling. When it starts running low, unscrew the cap and add fluid. Cost is probably 5-10.00 provided you already own an air compressor. Realistically, 32oz is way more than enough to completely flush the braking system. Most importantly, start with FRESH fluid minimizing mixing with old fluid as your dilution level is greater.
Using the two man method makes short work of bleeding the brakes aside of using a diaphragm bleeder. Gravity bleeding is too slow and isn’t as affective forced pressure methods.
Thanks.






