Chevelle with c5 zo6 brakes

[1badchevelle]

I would like to know if I need to run a hydroboost when I run these brakes or will the system I currently have work. I have disk/drum set up factory and a booster.

Thanks

[shep]

They should work with the booster you may have to change your master cylinder.

[Apogee]

The factory MC for a power disc/drum setup was 1-1/8" bore. You'll want to swap that out for something closer to 1" since your overall caliper piston area has been reduced relative to the stock calipers. If your engine doesn't generate adequate vacuum at idle (12-14" Hg or better) to effectively power the brake booster, hydroboost would be a much better option...or manual. All can be made to work and work well, but making a vacuum booster work with an engine that doesn't produce any tends to be a costly endeavor for what you get.

Tobin
KORE3

[David Clayton]

I have a Kore3 brake kit on my 67 with a small booster and 1 1/8 bore master cylinder and it takes a large amount of petal effort to stop. I am going to change it to a 1" when I get some extra money.
I just thought you might want to hear from some one who had made this mistake:banghead:

[B.W.T.ROAD]

I used a 70 Vette m/c on my 69 Camaro C5 front, C4 rear. Works great. Stock, I think, 11" booster

[Apogee]

I used a 70 Vette m/c on my 69 Camaro C5 front, C4 rear. Works great. Stock, I think, 11" booster

When using the early 67-76 Corvette MC's with a vacuum boosted system, be sure to specify the manual 4-wheel disc application so that you get the 1" bore with the deep pushrod hole as the Corvettes with power brakes came with a 1-1/8" bore...same casting, just machined for the larger piston.

Tobin
KORE3

[CHILI442]

When using the early 67-76 Corvette MC's with a vacuum boosted system, be sure to specify the manual 4-wheel disc application so that you get the 1" bore with the deep pushrod hole as the Corvettes with power brakes came with a 1-1/8" bore...same casting, just machined for the larger piston.

Tobin
KORE3

Is that the oval one? Is there a similar application that uses the rectangular design?

I'm running a '79 Trans Am master cylinder on my '68 442 that has ford explorer disks on the back and C5 brakes up front on ATS spindles. I think the bore is 1-1/8". The pedal is very stiff. I'd like to go down to a 1" bore.

[Joey316G]

What seems to be the master cylinder of choice for the c5 brake swap..I am looking to purchase a booster/master cylinder combo for my setup as well. If the 11" stock booster is sufficient, what master cylinder do you use. WHat year and from what vehcles or is there an aftermarket one or late model one that bolts up. Also on another not, whats everyone doing for a proportional valve?

[MJRIBEIRO]

I can tell you the 1" isn't quite enough line pressure. I'm looking to go with a smaller bore.

I use an adjustable valve pictured in this post:
http://www.chevelles.com/forums/showthread.php?p=1679617#post1679617

[HWYSTR]

I too use a 1 1/8 MC, ATS spindles, C5 brakes front & rear, and have a pedal effort issue. I'm using an aftermarket 9" dual diaphram booster though, and to me it feels like there's not enough boost. I too was going to drop to a 1" MC, though I believe that might be a crutch. I've heard that going to a 7/8" MC isn't an option either, since ti will require more pedal effort. I believe 1" is about the max. From what I've been hearing, the real way to correct this is to go with a hydroboost.

[Rick Dorion]

I love hydroboost but make sure you have good sticky tires as you will easily lock up the fronts!

[Rhino]

Has anyone looked into using the C5 master? It'd be my obvious choice when using C5 front and rear calipers. I'm sure there must be a reason it's not used.

[BonzoHansen]

C5 or 4th gen Camaro MC cannot be used?


What Rick says about tire quality is true - I can lock my 15" hoops up just with 12" rotors & portfield pads (and otherwise stock brakes). So I can only imagine what much better braking would do!

[Rhino]

C5 or 4th gen Camaro MC cannot be used?

I guess that's my question. I've seen a few guys allude to it's use, although I haven't seen much about it actually being successful.
https://www.pro-touring.com/forum/showthread.php?t=48572

On another forum it was noted that the MC backing plate needed to be shaved down 1/4? Of course, it isn't stated what booster he's using.

http://www.nastyz28.com/forum/showpost.php?p=1371495&postcount=3

[BonzoHansen]

What about this:


The search was on to find a suitable master cylinder that could help generate enough fluid pressure (since the PBR caliper piston area is very small when compared to the iron Moraine stock calipers). A 15/16" bore master cylinder was found to come stock on S-10 trucks. It also featured the outlet ports on the same side as our stock Chevelle master cylinder & features SAE flared seats for the brake line fittings (unlike those found on other quick take-up master cylinders), but some machine work is necessary to fit into our early design Moraine booster.

http://www.geocities.com/diels12000/BrakesII.html

[Rhino]

What about this:

http://www.geocities.com/diels12000/BrakesII.html

I had completely forgotten about that. I'm not sure if there's a difference, but people on camaros.net have specifically spoken about using the 4x4 S-10 master with great success on a late model booster as well as hydroboost.

[MJRIBEIRO]

Newer malibus had a 15/16" bore as well - no special machine work, ports are sae and on the proper side. I think the 1977 malibu should work -

http://www.napaonline.com/MasterPages/NOLMaster.aspx?PageId=470&LineCode=UP&PartNumber=39946&Description=Brake+Master+Cylinder+-+New

[CHILI442]

Newer malibus had a 15/16" bore as well - no special machine work, ports are sae and on the proper side. I think the 1977 malibu should work -

http://www.napaonline.com/MasterPages/NOLMaster.aspx?PageId=470&LineCode=UP&PartNumber=39946&Description=Brake+Master+Cylinder+-+New

Will that work for 4 wheel disks? I don't remember these cars having 4 wheel disk brakes from the factory.

[MJRIBEIRO]

It should - you'll just need external proportioning to get the rear right. I'll give it a whirl this winter.

[Rhino]

It should - you'll just need external proportioning to get the rear right. I'll give it a whirl this winter.

Do you happen to know where the residual pressure valves are for the Malibu? If it's built into the master, I don't think it would work. If it's in a distribution block then you may be ok.
Drums need ~10 PSI residual pressure to function properly. This much residual pressure on a disk would surely cause brake drag. (I believe they require ~2 PSI.)

[andrewb70]

Do you happen to know where the residual pressure valves are for the Malibu? If it's built into the master, I don't think it would work. If it's in a distribution block then you may be ok.
Drums need ~10 PSI residual pressure to function properly. This much residual pressure on a disk would surely cause brake drag. (I believe they require ~2 PSI.)

I am using the Malibu MC on my GTO. I got mine was a Raybestos reman unit and it was less than $25.

Andrew

[Rhino]

If you don't have a problem with brake drag, I guess it must be in the Distribution block. Good to know. :cheers:

[bochnak]

I can tell you the 1" isn't quite enough line pressure. I'm looking to go with a smaller bore.

I use an adjustable valve pictured in this post:
http://www.chevelles.com/forums/showthread.php?p=1679617#post1679617

How about Dorman master M99399 with a 3/4" bore for a 76' vette?

Look in up at the rock.

[stealth71]

I will be diving into this over the next few weeks. Hoping to run a C5 master on my stock vacuum booster. Figure the bore ratio has to be correct to match C5 brakes all around. I did a test fit on the booster and everything looks good. Used some playdoh to check the pushrod clearance and there is just a hair, so it should work.

Now I have to pull the rear for some work and switch the backing plates. I'll post what I find out and take many pics.

[bochnak]

I'll post what I find out and take many pics.

I know you will. It is greatly appreciated. Good luck.