Team Camaro Tech banner

What had non power discs?

2K views 27 replies 7 participants last post by  BC 
#1 ·
I'm converting my front drums to disc and need to know if there were any cars available with non power front discs that I can get a master cyl from. Also, can I use the combination valve from the power disc car with non power? If there were no non power disc cars then what cars came with the small booster that will clear the tall valve covers on a big block? I think that I heard they are from 3rd gen camaros/IROC's. Anybody know for sure and are they a direct bolt in?

Thanks

------------------
Visit My Website Check out my '72 Big Block Nova
 
#2 ·
I believe that it's been stated before that manual discs were an option in '67 only. I don't know about the use of the comb. valve.

If you go with a small booster, the 3rd gen is easily modified. The firewall bracket has mounting studs that need to be removed/drilled out to bolt it up. The pushrod is not threaded on the end but rather has an "eyelet". You can either cut off the eyelet and thread the rod or fabricate a bracket to accept the stock rod. This is the method I'm taking to give clearance for my BB swap.

------------------
Bret Copsey
'68 Camaro base coupe
'92 Caprice wagon
'98 Malibu
 
#3 ·
I found a booster/master that I can pick up out of an 85 Berlineta. Were those 4 wheel disc of disc/drum? Do you think that would work or is there a certain year I should look for? I also found a guy parting an '01 Camaro SS. Would the booster from that car work or are they totally differant?

Sorry for all the questions, but I want to make sure I get this right the first time.

------------------
Visit My Website Check out my '72 Big Block Nova
 
#4 ·
The 85 Berlinetta should be the right one. It could have come with rear discs or drums so you'll need to check that out. If you are getting it from a junkyard, they should be able to look up the Hollander exchange for you.

I can't remember now why, but I ended up ruling out using a 4th gen setup. I haven't gotten into the entire swap yet, but I think one problem with using the late model master is the possibility of the outlet ports being metric. If they are, I'll either try re-tapping or finding some adapter fittings. I'm not too concerned about it.
Hope this helps some.

------------------
Bret Copsey
'68 Camaro base coupe
'92 Caprice wagon
'98 Malibu
 
#5 ·
I would be getting it from a guy parting a car out, not a yard. If the booster will work then Im not real concerned with the master because I have a g-body master that I could use but I also have a cadilac rear disc setup that I would use if I happen across a 4 wheel disc master and combination valve setup. If not then I will just use the rear drums. I havent decided if it is worth the extra trouble for the rear discs, but since I have them I will use them if I can. This guy is giving me the booster/master and combi valve for $25, so I will use whatever rears that it is setup for.

------------------
Visit My Website Check out my '72 Big Block Nova

[This message has been edited by MrKwik (edited 12-03-2001).]
 
#7 ·
MrKwik,
Nice Nova!
Non-power front disks were installed on quite a few cars, so you have several choices if you want to go that way. Nova's, Camaros, Chevelles etc all could have had manual disks, so just ask for a manual disk/drum master cylinder at the parts store. Should be under $25.
if you want to go power, then it depends how much work you want to go. If you want to use the rear disks, then the setup from the '01 Camaro SS should be 4-wheel disk. Bret is right that the later cars used an eyelet that slid over a post welded to the brake pedal. If you want to use the stock setup, then you can cut off the eyelet and thread the rod like bret said. That will also allow you to adjust it if needed. Any of the boosters after 81 will have the mounting studs welded on them, but you can grind off the welds and tap them out. Then you will need to re-drill the holes in the mounting flange to the correct pattern to fit your car. Be careful to get the booster centered over the hole!

Also, if you go with the 4-wheel disks, you can get a master cylinder from a 79-81 TA that had 4-wheel disks, or a 70's Corvette one.

Does your car make sufficient vacuum to properly operate a vacuum booster? I can tell you that my big block is pretty mild, but only puts out 11" of vacuum, so it will not give me correct boost and I'm now converting to manual 4-wheel disks. I tried the smaller booster out of an 80 Camaro, but it ended up being harder to push and not work as well as a single diaphram, larger booster.

Good luck,
Bill C.


------------------
Bill C.
Colorado Springs, CO

68 Camaro... someday!
71 Chevelle SS
70 Nova
 
#8 ·
Thanks. I was under the impression that some novas and chevelles were available non power as well and the first thing I did was try to get a new master from the parts store. Everythinng disc brake that they list is power only, which is why I have pretty much decided to go the power route. I am pretty sure that the cam I am using now is way too hairy for power brakes, but I will be installing a different cam before the motor goes back in. I am going with a crane powermax. The cam is a little bigger than what I wanted to use but the crane tech guy said I have too much compression for a smaller cam and would run into detonation issues. It actually has more lift than the one I have now but less duration. He said this cam will be on the borderline for power brakes. I guess I could use a vacuum canister if I need to. I have a master cyl that came off of an S-10 with non power discs, but it has the shallow hole in the end like a power master, so I dont know how I would rig that up. I think I will get this Berlinetta booster tonight and build a new bracket or whatever I need to do and If I cant get it to work that I will go back to square one.

------------------
Visit My Website Check out my '72 Big Block Nova
 
#9 ·
You need to find another parts store, one where they still have BOOKS to look in! I done a lot of checking on these, so if you nee a part number, give me a hollar. You might also check out www.carparts.com to get part numbers to take to the local store, it's a pretty good site. I just recently bought a manual disk/drum master cylinder for a 73 Malibu because it has a 15/16" bore, so pedal pressure should be less than a 1" bore. It's for my Nova, so it should work good.
I will caution you against the canister, they don't work too good IMO. I tried one and it only helped about half of the first stab of the brakes, then all vacuum is gone and you are back to rock-hard pedal with not much braking. One thing to consider is that while the manual brakes will require more effort, they are much less effort than a power system that has no power assist!

Good luck,
Bill C.
 
#10 ·
I was dealing with NAPA. I basically fed them a list of the cars and years that I thought would work and none of them came up with non power disc. I will try the 73 Malibu though, you dont have the part number do you? I can live with non power, that was my first choice anyway. I didn't really want to use a canister because thats just one more thing in the engine bay. Is it safe to assume that the combination valve for a power or non power setup is the same? I have 2 right now. One from the 71 monte that the front discs came off of and I have one from a 82-83 cutlass. They both look the same, but is there any reason that I should use one or the other?

------------------
Visit My Website Check out my '72 Big Block Nova
 
#14 ·
UPDATE-
I went to O'reilly over lunch to fetch the master cyl. It looked exactly like the one that I had so I made him pull out the book and verify that it was a manual disc master. Aparently he goofed and looked up a 4 wheel drum master and did not show a master for manual disc on a 67 camaro. A little more digging turned up a manual disc application for a 67 Chevelle. He had it on the shelf and the final cost was $12.19!

Just in case anybody needs the number it is a
Cardone #10-1511

------------------
Visit My Website Check out my '72 Big Block Nova
 
#16 ·
Hey guys sorry to jump in on this, but I'm having the same problem except I will be running manual 4 wheel disc brakes. My 67 was 4 wheel drum, and I'm not to the point of buying my the master cylinder yet. I assume I will need to get a new combo valve too.

I currently am running a Dodge 8 3/4 rear that had drum brakes. I got rid of all the drum hardware and had the axles re-drilled for chevy bolt pattern. Then I went to my local circle track parts house, bought race car caliper brackets, hats and rotors. Then I welded the brackets on the housing. I'm using calipers from a 81 Z28. This set up just clears my Rally rims.

BC, you mentioned a 70's Vette. Does anyone have a parts numbers for this MC and combo valve?



------------------


Racer#00

Plain Jane 67
76 Trans Am Stock Car
74 Z28 (Basket case)
 
#18 ·
I know you're probably looking to go to the parts store to pick this stuff up, but if not Master Power carries it-they do show a specific combo valve
http://www.mpbrakes.com/MP8.HTM

I did find a listing for a 1970 Corvette w/ HD brakes on www.carparts.com but it doesn't specify if that means 4wd. Might try looking under Firebird too? Hope you find the application, we know since MP lists one it had to come on something. Please post back if you find it .

------------------
Bret Copsey
'68 Camaro base coupe
'92 Caprice wagon
'98 Malibu
 
#19 ·
I just want to throw this and see who proves me wrong, but I have been doing alot of brake research lately, and I don't remember where I saw it, but I read somewhere an article that stated that the combination valve for a 4 wheel disc setup is basically nothing more than a brake brake warning switch and perportioning valve. My understanding is that if you have a 4 wheel disc master then you can just use any aftermarket perportioning valve in the rear brake line, assuming that you are not worried about the brake light. I know that MP sells the 4 wheel disc combo valve, but it is like $150. where as you can get an adjustable unit for under $50. I have a rear disc setup that I have pretty much decided not to use because I also read that power assist was pretty much required for 4 wheel disc due the increased pressure requirements. Again, I don't know if there is a shred of truth to any of this, I just wanted to throw it out there and see what comes up. As far as 70's vette master cyls, did they even make a vette of that vintage that wasnt 4 wheel disc? I was also thinking that they would all be power as well though. I would be real interested to know if you can get an over the counter master tht will work for manual 4 wheel disc as well.

Sorry to be so long winded!

------------------
Visit My Website Check out my '72 Big Block Nova
 
#21 ·
Well you learn something new everyday! www.carparts.com definitely listed a power and a maual master cylinder, so there you go. Get a part number from their site and take it with you to the parts store if they can't look it up.

------------------
Bret Copsey
'68 Camaro base coupe
'92 Caprice wagon
'98 Malibu
 
#23 ·
Thanks guys, I'll check into it. I want to avoid a problem I had with my stock car.

The rear disc set up on my 67 is exactly what I run in my stock car. Before I switched to an aftermarket dual MC setup on my stock car, I was running a stock MC. I never could get the rear brakes right. I know I'll run into the same problem unless I get the right stuff.

I'm just putting my 67 back together now, so I won't be able to tell you guys if what I find works for awhile, but when I do get the car done, I'll let you know.

------------------


Racer#00

Plain Jane 67
76 Trans Am Stock Car
74 Z28 (Basket case)
 
#24 ·
Ok, here is some more info, sorry I've been away for a few days.

The manual MC part number for a mid-70's Malibu with disk/drum brakes is 1639. This MC has the 15/16" bore. I have not tried this one yet, so don't know how it works. I plan on putting this on my Nova, but I need the Chevelle to be running again...


For a 4-wheel disk brakes system WITH power assist, I have tried the MCs for both an 80 Corvette and 79 TA, both felt the same. The Corvette part number is 1749 and the TA part number is 1745. They operate the same, but the Corvette one looks like a typical Corvette MC that has two rounder looking bowls versus the TA one that looks just like normal disk/drum MC.

The other option is MANUAL 4 wheel disk brakes like I am putting on my Chevelle right now. The part number is from a 70's Corvette and is number 1371. Again, this one looks like a typical Corvette style that has the rounded bowls.

The issue of proportioning valves comes up a lot and here's what I think of it. For a disk/drum system, any prop valve from a like car should work fine. The important thing is to make sure the prop valve matches your system.

For a 4-wheel disk brake system, I see several options. First, if the car has good bias and doesn't transfer a lot of weight during braking, some people have said you can run without a prop valve at all. The big safety issue with any brake system is to make sure the rears don't lock up first, so running without a prop valve seems dangerous to me. The second option if you can live without the brake warning light is to run an adjustable prop valve in-line with the rear brake line. Then you simply need a line 'T' or splitter for the front brakes. If you like the idea of a brake light, you still have several options. First would be to get a prop valve for a 4-wheel disk brake car, either new or used, like the 79-81 TA, or Camaros that had 4-wheel disk brakes. That would probably be the best solution, but can be hard or expensive to get. The other option I am persuing is to use the 4-wheel drum brake distribution block and then put an adjustable prop valve in the rear brake line after the distribution block. I have heard this will work, but probably won't test it until Sat. The theory is that since this block only splits the front line (gives a nice place to hook both front lines to) and passes the rear line straight through, it should work fine, but gives you the brake warning light hook up. I just about have everything hooked up and in place, so I just need to bleed the brakes and test. I'll keep you guys posted as to how it works.

One last thing, IMO, the pressure required to operate the disk/disk manual system should be the same or less than a disk/drum system, but I won't know for sure as I never had manual disk/drum brakes on the car. One thing is that pedal travel will be more on a disk/disk system as it takes more fluid to push out the caliper piston versus the drum cylinder pistons.

Hope that helps,

I'll be back later...

Bill C.
 
#25 ·
So does the 4 wheel drum valve not provide any proportioning at all? I thought that any system be it drum/drum or disc/disc would need to cut back the pressure to the rears to keep them from lockup. Would you only need the adjustable valve with the drum/drum valve on a disc/disc system to fine tune the bias or am off track here? Also, is the residual pressure valve in a drum system in the master cylinder or the valve?

------------------
Visit My Website Check out my '72 Big Block Nova
 
#26 ·
I would use the drum brake block which only contains the brake warning switch.
I would put an adjustable proportioning valve in the rear line after the block.
I have seen photos of the adj prop valve before the block and it seemed to work OK, but I would worry about the brake warning light coming on due to pressure differences.

I've seen no residual pressure valves in the Camaro Master cyls and valves I have in my old parts bin. Yours may or may not have them.

Any manual master cyl used should have the deep hole in the rear of it to hold the pushrod from falling out. Some power booster type master cyls don't have the deep rear hole.
A 67 Camaro manual brake four wheel disc master cyl should have a 1" bore. Power brake uses 1 1/8".
David

------------------
Check my web page for First Gen Camaro suspension info:
David's Motorsports page
First Gen Suspension Page
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Chev 350 Can-Am Vintage Racer
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top