Brake System Killing Me!

[nicks67camaro]

I try to be self sufficient but this brake system is killing me. I just can't get them to feel confident. The car slows down but it should be throwing me into the windshield. The pedal with no vacuum feels pretty firm but during my test drive just not great.

System
DSE Brake Booster
1" ACDelco 18M974 screw top master
C6 Z06 6piston front 4piston rear
3/16 Copper nickel brake lines

Master was bench bleed and i used the motive power bleeder its bubble free but i feel like there could be some air left even though the calipers push solid fluid.

DSE recommends a 7:1 pedal ratio which would put the rod on the upper hole vs lower hole. I've read that the lower hole is what you use for power. When i had it on the upper hole it would feel really soft. In the lower hole the brake is in line with the gas pedal (dse dbw) its notibly lower than stock.

Do i continue to bleed this thing?
Is the top hole right? - I hate questioning DSE.
Should i bleed front brakes (rear port) first? Does it matter?

I have a caliper pressure gauge on order to check the pressure. I'm going to try the old 2 man bleeding and getting the rear higher to move any air bubbles closer to the plunger.

Any insight is appreciated


Thanks Nick

[oleyeller]

Bleed, Bleed, Bleed, and then Bleed some more. You got air!

[ignaro]

If your brake lines ever bend up, you could have air trapped in there. I had to re-run mine and had a bend over the trans tunnel that took forever to bleed. I also had a bad flare that looked fine but it was letting in a tiny bit of air as I bled it.

I took the car to the local brake shop and they made quick work of bleeding with a fancy pump and fixing my leaky flare. Now my manual brakes work great!

[nicks67camaro]

I think I need to keep bleeding! I'm still uncertain on the brake hole location. dse says ideal 7:1 pedal ratio that means the top hole which is manual?

[79 Camaro]

No expert but here's what has worked for me. Not running your brakes but I've used C5 brakes on a number of projects.

Two systems.

1.Power brake bleeder. Uses air pressure to push fluid from the master to the calipers. If you buy the kit the chain hold downs are junk. Use c-clamps. This will also push all the air out of the master. Careful if you have new paint it has a tendency to overfill the master and make a mess.
2. Mity vac that pulls the fluid from the master. A bit slower but it works.

Always start from the right rear, then left rear, then right front then left front.

[dontlifttoshift]

The upper hole is 6:1 and only for manual brakes. I'm surprised you even able to hook it up there as there usually isn't enough swivel in the pushrod to get up that high without really binding up.

Use the lower hole.

You always bleed the port that is closest to the pedal, if that port is the front brake line, bleed that first.

[nicks67camaro]

Thanks Don!

[jlwdvm]

The upper hole is 6:1 and only for manual brakes. I'm surprised you even able to hook it up there as there usually isn't enough swivel in the pushrod to get up that high without really binding up.

Use the lower hole.

You always bleed the port that is closest to the pedal, if that port is the front brake line, bleed that first.

I thought the port farthest from the master was always bled first (Passenger rear)???

[nicks67camaro]

Update: I pulled the booster removed any shims I used to use the top hole (based on what DSE said originally) put it back together on the lower hold with the pedal adjusted. I was able to lock up the brakes. I still think i have some air but they are WAY better.

[Barrrf]

if you feel like you might still have air, you could gravity bleed for a couple of days. It worked really well with my CTS-V calipers. I just ran tube from each bleed port up as high as I could and taped it to the car or a jack handle or anything and waited for a couple of days. It kind of makes a mess because of all of the fluid that will be in the tubes but it was really the only way I found I could bleed my stuff without a pressure bleeder.

[nicks67camaro]

Ya, i though about gravity too. I'mg going to bleed one more time manually with a buddy to see if it gets better.

[dontlifttoshift]

I thought the port farthest from the master was always bled first (Passenger rear)???

Look at it as two separate brake systems, front and rear. There are two separate pistons in the master cylinder, the only thing tying them together is a spring and brake fluid.

https://static1.pt-content.com/images/pt/2018/04/masterbrake3-1.jpg

Which ever port on the master cylinder is closest to the brake pedal is the system that you bleed first. Starting with the farthest caliper in that end of the system.

So in the case of the DSE setup, the front port is rear brakes and the rear port is front brakes. You would bleed the front brakes first starting with the passenger side caliper. The reason being is that the front piston won't really stroke all the way until the rear piston is bled. It just makes the job go faster, you can certainly do it "wrong" and be successful, I have.

[jlwdvm]

164581I thought I had my proportioning valve plumbed right, but now you have me second guessing myself.
Sorry to highjack the thread. Sorry for the pix being upside down! The port for the front breaks is nearest the radiator on the Wilwood valve.

Look at it as two separate brake systems, front and rear. There are two separate pistons in the master cylinder, the only thing tying them together is a spring and brake fluid.

https://static1.pt-content.com/images/pt/2018/04/masterbrake3-1.jpg

Which ever port on the master cylinder is closest to the brake pedal is the system that you bleed first. Starting with the farthest caliper in that end of the system.

So in the case of the DSE setup, the front port is rear brakes and the rear port is front brakes. You would bleed the front brakes first starting with the passenger side caliper. The reason being is that the front piston won't really stroke all the way until the rear piston is bled. It just makes the job go faster, you can certainly do it "wrong" and be successful, I have.

[nicks67camaro]

Joe, no hijacking at all. This is all good info.

[65 Fastback]

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