Flushed brake fluid all around and used dot4 to fill. It may be my imagination, I think I feel this way every time I bleed brakes, but pedal feels slightly spongy. Everything works great. Should I just go through the process again to see if it gets better? Or drive a couple days to see if it's actually normal and I'm just imagining things.

Has anyone else felt this way?

 

You probably have some air in the lines somewhere. I'm sure you did but, did you go in the correct order including caliper order once you were at the correct corner? Also, did you use sealed bottles of fluid or an old bottle?

I haven't done my Vette yet so I don't know the correct order. However, this happened to me with my GTR so I bled the lines again and got more air bubbles out by lightly tapping the caliper I was bleeding. The only way to be sure is to check it again.

 

If it does not feel right, then you missed something. Correct order is pass rear, driver rear, pass front, driver front. Fresh fluid always. Make sure you bleed BOTH valves on each caliper - there is one on the inside and outside. I use a Miti-vac pump to suck the fluid through so I can do it myself. Also, a standard flush will NOT do the ABS system. You need a GM tech tool to exercise that to flush that out.

 

So the order I went was passenger rear, drivers rear, passenger front, drivers front. I bled the inside pistons first then the outer on each caliper.

I’ll go through it again, may have let some air in somewhere.

I used a pump that goes on master cylinder to pressurize then I loosened each bleeder. I know I did not let the level get low enough to let air in at the master, but at the caliper I did forget to tighten a bleeder once and took the pressure thing off to top up, so it leaked and got air. I bled that one again but perhaps it still got some bubbles in there.

Wont take much to go through each one again so I’ll do that and see if it does the trick.

 

Yep, if Tracking, understand the desire to do it yourself with the frequent changes required.

I do have a hand vacuum pump brake bleeder and do my street rod that does not have ABS. But since I don't Track and change only every ~3 years in the Vette I have the dealer do that as the ABS has to be cycled to get all old fluid out of the valves etc.

 

I couldn't imagine the amount of fluid in the abs block would make much difference once it mixes with the rest of the fluid.

 

Factory Service Manual states bleeding order is right rear, left front, left rear and right front. This is because the Corvette has had a dual diagonal braking system since 2001. If you decide to do the two rear calipers first it doesn't make much difference which one you do first since they are both the furthest from the MC for portion of the brake system they are on. Same goes for following with the two front calipers. I always follow the FSM procedure just be be sure. Even using a pressure bleeder I sometimes get a soft pedal on initial brake application if I am changing pads at the same time. I have found that a short drive with some brake applications will sometimes get rid of the initial softness. However, it it doesn't disappear within a couple of miles it is time to bleed each caliper just a little to make sure no air got into the caliper during the bleeding process.

There is no real need to do the ABS bleed if you are doing the job yourself. The only fluid that remains in the BPMV is caught behind unopened valves. Some valves will be open if they weren't you wouldn't get any flow through the valve. The picture below shows the 2008 Corvette setup which will be similar to the C7 version. Sorry, I don't have a diagram for the C7.


One thing I know is you can clear the air out of the BPMV without going to the dealer. When I was installing my AP Brake Kit on my C7Z06 I had a very hard time getting one of the SS brake hoses attached to the brake line on the car. While I was doing this brake fluid was flowing every where and it took just long enough I drained all of the fluid out of the MC reservoir and got air into the BPMV. Even with some air in the system the brakes will work if you pump them and compress the air. The pedal can be very spongy but they will work. That is when you go for a drive and get the car up to a speed where you can lock the brakes if you pump the pedal hard enough and fast enough. The ABS will kick in causing the valves to move letting air bubbles past the valves. You have to be on a surface that lets all 4 wheels lock so the ABS will kick in at each wheel. Once you do that a couple of times go back and bleed the brakes again to see if they have improved. If you are lucky you will get it all out on the first try. It might take a few attempts. When I did mine I found a section of pavement near my house that had a fair amount of dirt on it from dump trucks coming onto the pavement. It worked perfectly as a loose grip surface so I could lock up the wheels at about 15 mph.

By the way if you are doing your own fluid flushes/bleeding you shouldn't have any qualms about hammering the brakes and using ABS. I know some people are unreasonably afraid of doing anything that harsh to a car but if you do this in a safe spot under controlled circumstances you will also learn a lot about your car.

Bill

 

So I bled brakes again today. Definitely had small amount of air in the passenger rear. All others were good. I think I may have not tightened the bleeder one time when I went to add fluid. All other calipers were fine. Brakes work fantastic now. Thanks everyone for the info!

 

Good to know. Trust your instincts and recheck.

 

Just make sure you don't over tighten these bleeders. They are soft metal and easy to damage plus I noticed corrosion on mine. So after messing up not one but TWO of them I replaced all of them with higher quality versions: ProBolt Stainless Steel Bleed Nipple M10 x (1.00mm) on my Z51 brakes. I also only use a pass-thru 6 point socket on them now. This way the fluid hose can go thru the socket and it will not round off the bleeders like an open ended wrench can. A flare nut wrench works too, but the pass thru socket aids in keeping the bleed hose securely on the nipple.

 

My thoughts, exactly. What I typically do on my ABS cars is do the flush at the calipers with new, then take it out for a drive and brake hard enough to engage ABS a few times which should circulate new fluid into the module and dilute the little bit of old stuff. I usually do the hard braking on a rainy or snowy day with my truck.. makes it easier, more consistent and less dramatic. But the vette doesn't intentionally see rain so I am not sure what I'll do since I haven't done a flush on the vette yet.

This method works for me anyway and I intend to do same on the C7... but I don't track my car.

 

I really like your taste in cars!!!! :-)