I'm swaping the disk set up off of a 73 nova so I ordered loaded calipers, hoses and master cylinder for a 73 nova thinking it would work for my camaro. I'm pretty sure the calipers and hoses are fine but when I got the m/c out of the box it looks just like my manual drum m/c, I called the part store and they said they had the same part number for the drum and disc m/c. So I had them check for a 69 camaro and they had different numbers so I had them order the manual disk m/c for my application. Why would the nova have the same m/c for the disc or drum set up? Also is it necessary to bench bleed the m/c? I've done it with out and it takes a little longer to bleed them but eventually it works, what is the reason to bench bleed the m/c?

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68 468 700R4, and here it is;
mutert23 (http://home.earthlink.net/~mutert23/)

[This message has been edited by MarkM (edited 07-29-2000).]

As far as I know the manual disc option was only available for 1967.
If someone else knows more please post the info here.
The drum brake master for 67 up had really small reservoirs. Did the one supplied from the parts store look small with equal size reservoirs?

I think the 69 used a different booster than the drum brake camaros. But not really shure what is different.

The main thing is the power brake systems used 1 1/8" bore, and manual used 1" bore. Either disc or drum brakes.

The 69 power disc brake master cyl has bleeder screws and is more squat than earlier masters.

It's hard to make the air go down hill to the calipers and bleed out of the system. That's why they recomend bench bleeding.

Sometimes it's hard to even get the master piston bores to fill so you can begin to pump the air out. A bubble of air wants to remain at the top of the brake lines.
I think Master Power has some info on master cyls on their web page.
David

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Check my web page for suspension info:
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67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

I am going to be running manual brakes, so should I get a master cylinder for a manual disc for a 67 camaro? The resevoir does look the same as the current one on my camaro. I thought that the disc m/c was more square than the manual.

[This message has been edited by MarkM (edited 07-29-2000).]

There are three master types on the following web page.

The top type is a 69 Camaro disc unit.
The second is a square type that is more commonly seen with second gen camaros disc brakes.
The third type down is the large reservoir type I have one of these on my 67 now. When I converted to four wheel discs, I ordered a master cyl for a 69 Z/28 with four wheel disc option. It is used on some corvettes too.

I know there is a smaller reservoir master used on manual or power drum brakes because I had it on my 67 origonally.

For some reason it's not shown on the page.

The only difference between the large reservoir masters is the bore size, either 1" for manual or 1 1/8" for power brakes. And the size of the reservoir, and weather they have a residual pressure valve behind the brass outlet seat.

MP also shows a "conversion" master cyl that looks like the top unit in the photo and a manual pushrod with clevis.
The late 60"s Corvette used a master cyl like this.

I have an old EIS brand brake catalog that shows a #E64985 Master cyl that is 1" bore and for front discs. It has the short type reservoir like the 69 style.


http://www.mpbrakes.com/MPMASTERS.HTM

Here is the manual conversion page: http://www.mpbrakes.com/MP29.HTM

hope this helps
David

------------------
Check my web page for suspension info:
David's Homepage (http://ourworld.compuserve.com/homepages/David_Pozzi/)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer



[This message has been edited by davidpozzi (edited 07-29-2000).]

David thanks for the help again. Well the guy at the parts store said that he would order a master cylinder for a 69 with manual disc so I hope that's what I get. Just out of curiosity what would happen if someone would try to operate disc brakes with a m/c made for drums? I measured the bore on the one that I got that is supposed to be for a 73 nova and it appears to be 1", and according to the master powers site manual disc can operate with a 1" bore m/c, so maybe it would have worked, but then again the m/c I have on my car now could also work, I just don't know.

Mark,
The disc brake master has a larger reservoir because the disc pistons are larger.
The drum brake master has a residual pressure valve just behind the brake line seat. It's a little rubber piece about the size of an eraser.

If you were to use a drum brake master cyl it would work, especially if it had the larger reservoir.
But the residual pressure valve in the front line would retain around 15 to 20 psi in the disc brake lines.
If you have a disc brake metering valve in the system or a combination valve. That valve PREVENTS any fluid under 50 psi from going to the front calipers.
So the effect of using a drum brake master with residual pressure valve should not cause any problems.

But if the metering valve is not working just right and the residual pressure leaked through, it would cause the front brakes to drag a little, wearing them out sooner and perhaps make them a little grabby.

A 2 psi residual pressure valve works well in any system to help keep the pedal high.

The residual pressure valve can be removed from your present master cyl by screwing a small screw into the hole in the brass seat and pulling it out. Then you can remove the rubber valve and re install the brass seat.

You might try it.
I just posted more photos of different master cyls on my Trans Am Page.
David

------------------
Check my web page for suspension info:
David's Homepage (http://ourworld.compuserve.com/homepages/David_Pozzi/)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

The photos help, my m/c looks like the top one for drum brakes so the new one should look different with bigger reseviors, correct? I'am also using a comintion valve that came off of the donor disc brake car.

Mark,
Are you refering to my web page or the Master power page?

The MP page has all large master cyls.
The top one on my page is the small one and is usually found on gm drum brake systems.

Any of them are available in either 1 1/8" or 1" bore.

The combination valve is a good way to go.

------------------
Check my web page for suspension info:
David's Homepage (http://ourworld.compuserve.com/homepages/David_Pozzi/)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

Dave, I was refering to your page, my manual drum m/c on my car now and the one I got for the 73 nova look the same. I'm supposed to be getting the m/c for a manual disc 69 camaro on monday so I'll let you know if it looks different. Can the combination valve go bad? The one I got looks pretty dirty because it was setting in a junkyard for who knows how long, I'm soaking it right now in some solvent so I hope it's all right. I need to get the combination valve, spindles and m/c painted on monday so I can start the project on wendsday when I have time off rest of the week and the weekend, when I start a project I want to be sure I have enough time to finish it, if for some reason I can't do it at that time I'm going to have to wait until next spring, so it might be awhile before I know if everything is in fine working order.

David, I got the new master cylinder today and it looks like the one on your page on your 67 with 4wdb and the picture of the one below it, it's got dual bails unlike the previous one. On your page where you have two pictures showing the short and deep holes for manual and power, just to make sure the one I got is for manual brakes, can you tell me about how deep this hole should be. I guess I don't trust the parts store 100%, and I don't want to go through the trouble of having it painted the same color as my car to find out it's wrong.

Mark,
I wouldn't soak the combination valve in solvent. It might harm the seals.
Washing it off would be OK but if it soaks long enough it might get solvent in contact with the seals and I don't know if they will swell or shrink.

The short depth master is 3/8"
The master cyl depth is 1 5/8" for the squarish one, or I have the two bail round type that is 1 3/4" deep.
This is measuring to the most rearward part of the casting just behind the snap ring.

Good thing I never threw anything away!
David

------------------
Check my web page for suspension info:
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67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

Thanks for the information, the indintation in the rear of my new master cylinder is about 3/8" deep, is that right for a manual application? I guess I'll know for sure when I pull the original one off of my car.

Mark,
NO the short depth is for power brakes only.
The danger is the manual pushrod may fall out of the short depth master cyl.

I don't know how easily this can happen but you need the deep hole master.
I'd think allmost all the 1" masters would be the deep type as they are all used on manual systems.
David

------------------
Check my web page for suspension info:
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67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

Curse that parts store! this is why I'm glad there are places like this that I can ask questions and get knowledgeable answers. I'm going back up there tomorrow and looking this part up myself, I'll let you know what I find out. I don't know if this means any thing to you and I'm going to do some searching on it right now but the part is a Bendix m/c part#R11479.

David, I went to wrench head.com and typed in the part number and here is what it states http://www.wrenchead.com/wh_mem/power_search.asp?mscssid=02a1c205ad011d5e9a863eb9e 576 88f4 (http://www.wrenchead.com/wh_mem/power_search.asp?mscssid=02a1c205ad011d5e9a863eb9e 57688f4) , it doesn't say what car it's for though, what do you think? The links not taking you strait there, you'll need to type in Bendix and R11479.


[This message has been edited by MarkM (edited 07-31-2000).]

[This message has been edited by MarkM (edited 07-31-2000).]

I think I got the right one now, I got the one for a 67 camaro with manual disc and it's rounded in the front and sqwuared off in the rear, the front resevior is bigger than the rear and it has the deep hole like my original one does. The swap should be done in a couple days so I'll let you know if it goes well.

Good Luck!

David

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Check my web page for First Gen Camaro suspension info:
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67 RS 327
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65 Lola T-70 Can Am Vintage Racer

Mark, did you get the right master cylinder?
If so do you have a part number? I did the same conversion and I think they may have given me a power m/c. Both resevoirs are the same size. Thanx. Sean

I guess I got the right one, it brakes fine. I don't have a part number becuase I took my drum m/c back as a core in the disks box. It did have a deep hole for pushrod, I went through 2 others with a 3/8" hole which made me believe they were for power, I ordered the m/c for the 67 with manual and everything is working fine.