69 Chevelle SS front brake bleeding

[mockingbird812]

Originally Posted by Mr70

Too Late to add anything to this,but just went through bleeding my own brakes recently with a similar outcome.

70s have the same plunger? Do you know how this pressure metering valve actually works?

[Kurt S]

http://www.camaros.org/brakevalve.shtml#mv

[mockingbird812]

Originally Posted by Kurt S

http://www.camaros.org/brakevalve.shtml#mv

Perfect Kurt - Thank you!

[Kurt S]

You should know that I edited/created that page (JohnZ wrote it), and I *still* didnt' remember that I need to depress that plunger. So thanks for bringing this back up!

[Jonesy]

I have had a hell of a time with bleeding brakes since I restored my car. Never depressed the plunger. Guess I may now know why. Its only been 12 years

[mockingbird812]

Originally Posted by Kurt S

You should know that I edited/created that page (JohnZ wrote it), and I *still* didnt' remember that I need to depress that plunger. So thanks for bringing this back up!

Kurt - Ha, does my heart good that a details guy like you can forget some of this stuff too!

['69Novajoe]

Hi guys, first of all, I hope all of you are taking care and keeping safe with all of this virus stuff around!!

I know this is an "old thread" but I'm hoping that some of you might still be getting notifications when someone posts here. I have a '69 Nova SS with drums in the rear and discs up front, all stock. Here's my dilemma.....I had been experiencing a low pedal for awhile so, even though I had the whole system rebuilt about 10-15 years ago, I decided that maybe the master cylinder was at fault. I brought it to the guys who rebuilt it (they sleeved the master, wheel cylinders and calipers with stainless back then) to have them redo the master. They said it really didn't look that bad but put in a new "kit" anyway. I started the installation yesterday, bench bleeding the master, installing it and then proceeded to bleed the whole system. I'm using a "one-man" vacuum pump style tool. I was doing pretty good until I got to the front brakes. Very little fluid (I thought) was coming out from the passenger side caliper. When I started on the driver side, nothing was coming out!! I even took the bleeder screw out of the caliper completely and stepped on the brake pedal. Still nothing, not even a drop!! Then I remember searching different sites for pointers on bleeding brakes and ran across this thread. I called the brake guys and mentioned the plunger on the metering valve to allow the fronts to be bled and he said that it shouldn't be necessary. He said to just start checking for a blockage. The first thing I did was disconnect the metering valve. When I tried to push in the plunger it wouldn't budge!! My question to you guys is, how much pressure does it take to push that in? Also, in normal operation, does that plunger go in and out every time you apply the brakes?? The reason I'm asking the question here is, I'm having a hard time getting a call back from the brake guys right now. Thanks in advance for any help you can provide!!

[ScottG]

That plunger senses pressure differential and moves the plunger in respect to the difference. If you have a total brake pressure loss the plunger would go fully into a failure position and that turns on your red BRAKE dash warning light. If it gets partially tripped it would limit brake fluid flow and you would see very little fluid volume when bleeding the brakes.. I always gravity bleed after a test drive, take off the master cylinder cap and put a section of vacuum line on the bleeder when it is open. The vacuum line keeps the fluid from chewing paint and you can watch the fluid to see if there is any air in the fluid..

['69Novajoe]

Hey Scott, thanks for the reply. I think you might be talking about the "distribution block" that has all the brake lines going to it and an electrical connection that would do exactly what you said, turn on the "red BRAKE dash warning light". The metering valve is what's described in a previous post. Here is a link to what it looks like...
http://www.camaros.org/brakevalve.shtml#mv

[mockingbird812]

Hey Joe. You can save your effort in telling us that you have “69 Nova SS”. We all know that you are the original owner of a very special 69 Nova SS and that is just super cool! So, not to be a smart aleck but what does your manual say? I would probably never have figured out about depressing that plunger on the pressure metering valve without checking my manual (and checking with the smart dudes around here). Do your brakes have the metering valve with the plunger (edit: I just checked yr CRG link and I think it says all 69 rear drum front disc brake cars have them)? If it does have the plunger then I’d clamp it down and give the bleeding another try.

If you don’t have a manual maybe someone (hey Wilma!) can provide a peek at one.