Factory Brake Booster with Disc

[1999corvette]

I'm pretty sure the boot on my CPP setup is thicker than the one you have.

It fits so tight, that if you pull the booster off the brackets, the boot will stay between the brackets because it fits too tight, you have to loosen the brackets at the firewall to get it out.

[CPPJEFF]

Originally Posted by 1999corvette

I'm pretty sure the boot on my CPP setup is thicker than the one you have.

It fits so tight, that if you pull the booster off the brackets, the boot will stay between the brackets because it fits too tight, you have to loosen the brackets at the firewall to get it out.

Thats why we are making the new boot. Pretty soon we will have this perfected....

[1999corvette]

Originally Posted by CPPJEFF

Also not all firewalls have 5 holes like that some just have 2.

My truck was a non power brake model, and came with 4 holes, but only used 2.

The 2 extra holes had bolts in them I guess to plug them up, and they were located as if you were to turn the master cylinder counter-clockwise maybe 1/8th of a turn.

[chevyguys]

Originally Posted by 1999corvette

My truck was a non power brake model, and came with 4 holes, but only used 2.

The 2 extra holes had bolts in them I guess to plug them up, and they were located as if you were to turn the master cylinder counter-clockwise maybe 1/8th of a turn.

Did the bolts that plugged the two extra holes get in the way of brackets provided by CPP?

I have three cabs here, two 65 and one 66. All have 4 or 5 holes. My buddies 66 GMC has 4 holes. Just an FYI.

Jeff, glad to see that something is being done to resolve this. Hope to be able to get my hands on the fix soon.

[1999corvette]

I took those bolts out, and it did look like they would get in the way of the CPP brackets.

Why so many cabs, multiple project trucks?

[chevyguys]

Actually they are all parts trucks.. I sort of fell into them. I have two big back window cabs (using one) and a small window. I'm actually getting ready to get rid of one of the parts trucks (or what's left of it) I was going to offer the whole thing for free to board members if they take the whole lot (no cab or font clip (longbed), it's a roller.

I hope I dont get flagged for this... Since I'm not selling anything

[Captainfab]

That's what I make and was offering you in my previous post

Originally Posted by chevyguys

Thank you for the information. I am aware of the documentation. My concern is with the fact that there are already 5 holes in the firewall for the master/booster assembly. It seems a shame to have to drill two more. How about a bracket for the booster that allows the purchaser to use the existing holes in the firewall?

Also, since the dust boot does not seal the firewall how is that handled?

Thanks for responding here in the forum. I'm sure this information will benefit many members.

[chevyguys]

Originally Posted by CPPJEFF

Thats why we are making the new boot. Pretty soon we will have this perfected....

Jeff any idea on when this new boot will be available. I have called a few times trying to get one with no luck.

[ChevyK10Dan]

Originally Posted by chevyguys

Thanks Tony! I'll give it a try and see how it goes...

Originally Posted by flips72

i have a factory booster on my truck works great. i used a master cyl for a 72 and portioning valve off the same with disc and drum. no problems at all.

Originally Posted by BIG V

i think you can bolt on a 1971-72 chevy pickup master cylinder with manual brakes on to the factory 63-66 power brake booster....

I also want to use the factory power booster and brackets with a dual reservoir master cylinder and proportioning valve.

Is the 71-72 non power setup the only master that works without modification?
Is the factory plunger rod long enough to work correctly, with the non power master cylinder for the 71-72?
How long have some of you been using this setup, and any complications?

I also have a CPP and recently bought a parts truck with the Factory Power Brake Unit. If possible I was hoping to use the master cylinder and/or proportioning valve from the CPP system on the factory booster and brackets to save a few bucks if possible.

Thanks For any updates on 71-72 master cylinders or Info about compatibility on the CPP stuff. I will guess the bore is to deep on the CPP Master and will not work.
Thanks,
Daniel

[Captainfab]

If the factory power booster still has the single reservior master on it, just compare the back of the piston with the CPP master. Measure the depth of the bore in the back of the piston and see if they are the same.

[ChevyK10Dan]

Thanks for the reply,

I had some time and found the factory single master has a 1" bore and the CPP website shows a 1 1/8" bore for my kit.
I also looked up the bore on the 71-72 master cylinders and when equipped with disc/front drum/rear it has a 1 1/8" bore. When equipped with drum/front drum/rear then the bore is the same 1" bore as the factory single master.
So now I am trying to find the difference in the two 71-72 master cylinders and if a proportioning valve can be added to a 71-71 master cylinder that was originally a drum/drum to make it disk/drum, or if this is a safety issue and can not be done.

I am still hoping to hear from some of the members that have done this before to find out which master they used 71-72 drum/drum or disc/drum.

If all else fails I would guess I could just add 1/8 to the rod and make it the correct length?

Thanks,
Daniel

[Captainfab]

If you're running a disc/drum brake system on your truck, then you will need a disc/drum master cylinder as well as a disc/drum proportioning valve. This really isn't complicated at all if you use a master and prop valve from a '71-'87 C10 with power brakes.

You cannot change the 1" bore of a master cylinder by adding 1/8" to the pushrod. There is no relation whatsoever between the two. The bore of the master is the diameter of the bore in the casting where the piston resides.

[ChevyK10Dan]

I have a disc/drum master with a proportioning valve in there now with the CPP kit.

I was referring to adding 1/8 to the original power brake booster rod to be able to use the CPP master (1 1/8") and Proportioning valve or factory 70-80 Chevy master (1 1/8") and 70-80 proportioning valve.

I have had the CPP kit for a while and I really don't care for it.

I read early in this post that some were able to use a factory MC without modifying anything and was trying to find out how.
If they still have drum/drum then I guess they used the dual reservoir drum/drum MC from the later trucks because it has the same bore (1") as the factory 60-66 power brake setup.

I would still like to know if someone with disc/drum has used the factory booster and brackets with a disc/drum setup and how they did it, and what they modified if anything.

thanks,
Daniel

[chevyguys]

CPP never came through with the boot. Anybody have any idea's as to where to find a boot to seal the firewall?

[CPPJEFF]

Originally Posted by chevyguys

CPP never came through with the boot. Anybody have any idea's as to where to find a boot to seal the firewall?

Wow correction let me check on this boot and see if they were ever finished up. Sorry about that.

[chevyguys]

Jeff,

The last PM I got from you was the following:

"I have yet to see them. Sorry about that , new items sometimes dont come with accurate ETA dates so i just as soon not give you one. Thanks"

On November 22nd.

Are the boots now available?

[CPPJEFF]

Originally Posted by chevyguys

Jeff,

The last PM I got from you was the following:

"I have yet to see them. Sorry about that , new items sometimes dont come with accurate ETA dates so i just as soon not give you one. Thanks"

On November 22nd.

Are the boots now available?

Ok i just spoke to the owner and those have not come in yet. This is the kind of normal delays we go through when we manufacture a new part. Sorry about that.

[apachedaddy]

http://67-72chevytrucks.com/vboard/s...it+brake+lines.

This thread may help with some of your questions well I hope it does at least. Have a great day
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