Factory Brake Booster with Disc

[chevyguys]

Anybody have any experience using a factory 66 power brake booster with Disc/Drum brakes? I Bought the CPP grandslam drop kit with booster and master cylinder. It fit's horrible. Once everything is bolted up you still have to somehow seal the original 2"hole the mastercylinder used to fill. The new CPP booster and dust boot sit away from the firewall and just allow weather, heat, fumes and noise to enter the cab. I know I could probably buy a boot to seal the firewall but the CPP kit just seems like crap.

So my question is. Can I use my factory power booster and just put a disc master cylinder on it? i'm concerned about the bore and stroke needed to make everything work. Anybody done this?

[Captainfab]

I haven't installed a disc/drum master on an original booster, but I do have an alternative if you're interested. There is a link in my sig.

[LILRED66]

A dual chamber master cylinder can be installed on the factory power brake booster, along with a porportioning valve, to compensate for disk/drum brake system, without modification.

[chevyguys]

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

[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.

[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....

[Pinepig]

Originally Posted by chevyguys

Anybody have any experience using a factory 66 power brake booster with Disc/Drum brakes? I Bought the CPP grandslam drop kit with booster and master cylinder. It fit's horrible. Once everything is bolted up you still have to somehow seal the original 2"hole the mastercylinder used to fill. The new CPP booster and dust boot sit away from the firewall and just allow weather, heat, fumes and noise to enter the cab. I know I could probably buy a boot to seal the firewall but the CPP kit just seems like crap.

Could you post a pic or two of the problem, On Monday I was going to drop the hammer on the grand slam kit.

I know first post.

[1999corvette]

When I put on my CPP booster and master, I found the boot had to be turned a specific way to fit the hole, which required taking off the master, and loosening the brake booster brackets enough to get the pressure off the boot, so it can be moved around.

The boot has a bend to it, and when I put it on, there was a gap between the hole and boot.

[1999corvette]

You don't have to take off the master cylinder, but it makes it lighter and much easier to support and move around by yourself.

[chevyguys]

Originally Posted by 1999corvette

When I put on my CPP booster and master, I found the boot had to be turned a specific way to fit the hole, which required taking off the master, and loosening the brake booster brackets enough to get the pressure off the boot, so it can be moved around.

The boot has a bend to it, and when I put it on, there was a gap between the hole and boot.

Here are a few of the problems with the CPP booster.

1. The bracket does not line up to any of the factory holes (5) for the factory brake booster.

2. The boot does not seal the firewall, it only acts as a dust boot for the booster.

Honestly, I could just modify the firewall, fill the holes and put another dust boot in to keep weather and heat from the engine out of the cab. However, I don't want to do that as I have no desire to modify a factory low hump, big back window, Air conditioning cab!! This is why I purchased the kit from CPP as it was a "bolt-on" kit!!

Here are a few pic's of my situation... Which by the way I am just going to use a factory booster with a 71-72 Master as others suggested.

[chevyguys]

Originally Posted by Pinepig

Could you post a pic or two of the problem, On Monday I was going to drop the hammer on the grand slam kit.

I know first post.

I would avoid the CPP kit and go with Early Classic Enterprises. A good friend of mine is building a 66 GMC and bought the same kit from ECE and everything bolted up just fine. I ended up with bad rotor's (casting material not cleaned out of grease pockets) Missing Calipers that I had to fight to get and was accused of lying to them. Brake hoses that were too short, and a booster that requires Modification to install. Not to mention they quoted two different prices to me and overcharged me by "accident" on the shipping.

Will never buy anything from CPP again!

[1999corvette]

That's different looking, I mean the boot, yours has a flex type boot.

[Pinepig]

Originally Posted by chevyguys

I would avoid the CPP kit and go with Early Classic Enterprises. A good friend of mine is building a 66 GMC and bought the same kit from ECE and everything bolted up just fine. I ended up with bad rotor's (casting material not cleaned out of grease pockets) Missing Calipers that I had to fight to get and was accused of lying to them. Brake hoses that were too short, and a booster that requires Modification to install. Not to mention they quoted two different prices to me and overcharged me by "accident" on the shipping.

Will never buy anything from CPP again!

ECE has the same type of kit ( grand slam )? I gotta go look again.
Thanks for the pics.

[chevyguys]

Originally Posted by Pinepig

ECE has the same type of kit ( grand slam )? I gotta go look again.
Thanks for the pics.

Yes they do but you have to call them.. they don't have a generic kit on their website.. They tailor it to your truck and have many different options. The cost comes out to about 100.00 more than CPP's kit but you get quality parts such as the bearings, rotors and calipers. I helped my buddy put his together and everything fit excellent.

[Pinepig]

Thanks again, I'll be getting in touch with them on Monday.

[CPPJEFF]

Ok i read this and i appologize for the confusion we have installed this booster for years on 63-66 Chevy trucks and we have actual tech articles from the magazines on our website to support the installation. You do need to drill a couple holes in the firewall as indicated in the instructions let me post some pics. Thanks Jeff.

[CPPJEFF]

http://www.classicperform.com/tech_a...topBraking.htm

Here is a link to a National magazine Installation we did on a 1965 Chevy Truck.

[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.

[CPPJEFF]

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.

Ok this is actually a great topic. First off this is unreal timing as we are in the middle of making a firewall boot for this application and i will post a picture to show you guys. Also not all firewalls have 5 holes like that some just have 2. I really like the picture posted of the brackets we supply not ice how thick they are in contrast to what other vendors supply? I will gladly make you a firewall plate for free or something to help cover those holes if that would help you. Take a loot at this firewall boot NOBODY has anything like this!! CAN SOMEBODY UPLOAD THE PICTURE FOR ME????

[chevyguys]

Originally Posted by CPPJEFF

Ok this is actually a great topic. First off this is unreal timing as we are in the middle of making a firewall boot for this application and i will post a picture to show you guys. Also not all firewalls have 5 holes like that some just have 2. I really like the picture posted of the brackets we supply not ice how thick they are in contrast to what other vendors supply? I will gladly make you a firewall plate for free or something to help cover those holes if that would help you. Take a loot at this firewall boot NOBODY has anything like this!! CAN SOMEBODY UPLOAD THE PICTURE FOR ME????

Where would we get the picture? Feel free to PM me the info.

[CPPJEFF]

Originally Posted by chevyguys

Where would we get the picture? Feel free to PM me the info.

What is your e-mail?? I will send you the pic. Thanks

[62 short step]

Subscribed, since I've bought a cpp master & booster. (I have the same problem with the boot)

[CPPJEFF]

Originally Posted by 62 short step

Subscribed, since I've bought a cpp master & booster. (I have the same problem with the boot)

Give me an e-mail so i can send you the proto type pics of the new dust boot. Its a plastic mold right now but it will be very cool!!

[62 short step]

Originally Posted by CPPJEFF

Give me an e-mail so i can send you the proto type pics of the new dust boot. Its a plastic mold right now but it will be very cool!!

PM sent with email.

[1999corvette]

I took some pics of mine

A shot of the underside of the brackets and seal