Front Discs will not engage

[Bare64]

Here is what I have found (done) so far:

1. Went ahead and ordered a new proportional valve due to rod being stuck, do not want sister getting into a bad situation if rod sticks again and she has no brakes. I can get this valve in "fixed" and "adjustable", which would you guys recommend?


2. Bought a Master Cylinder Bench Bleeder Kit

3. Question about this angle on the Master Cylinder, seems pointed up way to high:


4. I am thinking who ever installed the bracket installed it upside down, it seems the master cylinder would be about parallel if the bracket is rotated 180 degrees, right?

[fleetsidelarry]

my bracket is installed like that but the booster and MC sit level.

[Bare64]

Originally Posted by fleetsidelarry

my bracket is installed like that but the booster and MC set level.

Pretty sure this one is upside down, the bracket is angled. I think if I flip it the booster and master cylinder will level out. At that angle getting the master cylinder bleed properly I think would be non-existent.

Called Summit, the valve is not available in "adjustable" form, no clue why the site says available that way.

Just figured out where my PS leak is coming from too, Unisteer sent me a bad hose........leaking at the crimp coupling, crap. They are sending another, so all is good here at least. Great, easy to install kit BTW if any one is looking to move to rack and pinion.

[fleetsidelarry]

re: picture in my previous post: backside of my booster is angled opposite of bracket

if your booster is not angled like mine then I'd say you're correct about flipping the bracket.

[Bare64]

[QUOTE=fleetsidelarry;6983114]my bracket is installed like that but the booster and MC sit level.

Your booster looks like it has a "bump" on top where the top bolts go on and flat on the bottom, the backside of mine is flat top to bottom. I am going to rotate the bracket, see if it levels out.

[fleetsidelarry]

more I think about it, the more I think that rotating the bracket will just cause the front to be lower by the same amount that it is higher now BUT hopefully I'm wrong. obviously you need to try it.

[Bare64]

Originally Posted by fleetsidelarry

more I think about it, the more I think that rotating the bracket will just cause the front to be lower by the same amount that it is higher now BUT hopefully I'm wrong. obviously you need to try it.

I did, it took a couple of 3/8" ID X 1/2" wide spacers.
Level:


How much is too much to tighten this rod end to shorten it? Figured this one out, it just goes so far. Pushed in brake pedal, just enough clearance now.


I seem to have a clearance issue between the MC and the Booster Rod:

Thanks for you help and tips.

[53lowdown]

Regarding the Master Cylinder angle - See thread http://67-72chevytrucks.com/vboard/s...d.php?t=459249

According to CaptainFab's post, it doesn't seem to matter that the master is angled up.

[Bare64]

Originally Posted by 53lowdown

Regarding the Master Cylinder angle - See thread http://67-72chevytrucks.com/vboard/s...d.php?t=459249

According to CaptainFab's post, it doesn't seem to matter that the master is angled up.

This one was pretty severely tilted, looking at CPP install instructions, trouble shooting guidelines air could get trapped in the front piston according to their drawing. It's level now so I am just going to go with that, keep working to get system safe and reliable.

[fleetsidelarry]

Originally Posted by Bare64

I seem to have a clearance issue between the MC and the Booster Rod:

Thanks for you help and tips.

so did I when I did mine. It's been so long ago that I don't remember what happens but I think the brakes lock up if this isn't right. I ended up putting flat washers between the MC and the booster as a quick adjustment fix, with the intention of going back and adjusting the rod if the quick fix worked. it worked and I never got around to trying to "do it right". that was 10 years ago (give or take).

[Bare64]

Originally Posted by fleetsidelarry

so did I when I did mine. It's been so long ago that I don't remember what happens but I think the brakes lock up if this isn't right. I ended up putting flat washers between the MC and the booster as a quick adjustment fix, with the intention of going back and adjusting the rod if the quick fix worked. it worked and I never got around to trying to "do it right". that was 10 years ago (give or take).

Lowered it ~1", maybe a tad more yesterday. I think the biggest issue was the failed proportional valve.

[fleetsidelarry]

Bare64, I looked at the info that came with my system (Master Power Brakes). it said the booster pin should almost touch the MC piston, with approximately 0.020 gap but not more than 1/32 (which is 0.031). if the pin is too long (pushing on the piston) it will cause the brakes to drag.

[Bare64]

Originally Posted by fleetsidelarry

Bare64, I looked at the info that came with my system (Master Power Brakes). it said the booster pin should almost touch the MC piston, with approximately 0.020 gap but not more than 1/32 (which is 0.031). if the pin is too long (pushing on the piston) it will cause the brakes to drag.

1mm is as far away as I could get it, hopefully that is enough. Ended up with 7mm from MC seat tip to the flange, 8mm on Booster with rod all the way in.

[Modges'66]

I know that I am late to the party, but can you not adjust the length of the rod sticking out of the booster to create the gap that you need between the it and the master-cylinder? Isn't that why there is a hex on it?
I could swear that mine was adjustable there...

[Bare64]

Originally Posted by Modges'66

I know that I am late to the party, but can you not adjust the length of the rod sticking out of the booster to create the gap that you need between the it and the master-cylinder? Isn't that why there is a hex on it?
I could swear that mine was adjustable there...

Your correct, I loosened the hex nut, then ran the rod in until I had enough clearance, tightened the nut back down..........was this wrong?

[Modges'66]

I do not know if you are bleeding with a pressure bleeder, or manually.
I am assuming that you are bleeding manually.
What can sometimes happen when bleeding manually is; because of the travel of the pedal you may not have the volume needed to force all of the air bubbles downhill to the calipers without releasing the brake pedal, at which time the bubbles creep back uphill...
Thus, each time that you tighten the bleeder, the air returns to the highest point in that line, making it impossible to evacuate.
With a pressure bleeder however, you can continuously exhaust the fluid to assure that no bubbles return to the highest point in the line.
My advise from experience on a '69 Corvette that had 4-piston calipers & multiple bleeder screws that never seemed to bleed properly, is get or rent a pressure bleeder!
And like mentioned earlier, you may need to remove your caliper and insert a spacer block which is the same thickness of your rotor between the brake shoes to obtain a bleeder screw angle @ 12:00 for better bleeding.
I have often done this trick with dirtbikes to bleed the brakes.
I hope that this helps.

[Bare64]

Originally Posted by Modges'66

I do not know if you are bleeding with a pressure bleeder, or manually.
I am assuming that you are bleeding manually.
What can sometimes happen when bleeding manually is; because of the travel of the pedal you may not have the volume needed to force all of the air bubbles downhill to the calipers without releasing the brake pedal, at which time the bubbles creep back uphill...
Thus, each time that you tighten the bleeder, the air returns to the highest point in that line, making it impossible to evacuate.
With a pressure bleeder however, you can continuously exhaust the fluid to assure that no bubbles return to the highest point in the line.
My advise from experience on a '69 Corvette that had 4-piston calipers & multiple bleeder screws that never seemed to bleed properly, is get or rent a pressure bleeder!
And like mentioned earlier, you may need to remove your caliper and insert a spacer block which is the same thickness of your rotor between the brake shoes to obtain a bleeder screw angle @ 12:00 for better bleeding.
I have often done this trick with dirtbikes to bleed the brakes.
I hope that this helps.

Thanks, I will keep this in mind

[Mathew21]

Curious if you gotten this resolved?