Opinion on Master Cylinder replacement

[Bodied67]

Morning guys,

So I’m finally taking the plunge on swapping my front drums to discs and as I’m sourcing all my parts and browsing kits I’m looking for some input on which route to take with the master.

I don’t like the big bulky look of the current master I have now so I want to swap it out to something more appealing to the eyes. I’ve read some people love the manual brakes some people don’t, I’m gonna use this truck as a nice cruiser nothing more nothing less and going to retain the rear drums for now (may upgrade in the future).

It’s got a LS with a mild cam so I’m curious about deleting the vacuum line and whatnot or just keep it how it is and find a compatible master. Only real issue at the moment is clearance with a fuel regulator that the previous owner mounted right on the firewall as you’ll see in the photo. Any thoughts or input on what some of you guys did or used would be greatly appreciated as always.

[Steeveedee]

A 1/2T truck has manual brakes, with power brakes as an option. With the correct geometry to the linkage, I've found stock manual disc brakes do not require too much pedal effort. You can get a cleaner look with a hydraboost unit, which will also leave room for the regulator. Just takes money.

[PbFut]

Hydroboost?

[Steeveedee]

Yeah, that thing! Hydraboost turns out to be skin creme.

[Bodied67]

If I was doing a full blown resto mod/build I would 100% go hydro but for the time being I’m looking for something more cost effective lol

[57taskforce]

Originally Posted by PbFut

Hydroboost?

This has my vote. One of the best things I’ve done to my K20.

[Rust_never_sleeps]

So, is just swapping the dual-diaphragm booster for a single an option you're considering, or is that still too bulky a look?

[Bodied67]

Originally Posted by Rust_never_sleeps

So, is just swapping the dual-diaphragm booster for a single an option you're considering, or is that still too bulky a look?

I’m starting to think this would probably be the easiest route to take and most cost effective too but figuring out if I have enough vacuum is another issue I’ve had my mind on

[Accelo]

Is your LS an automatic? Are you running the stock converter in the transmission?
If your converter is stock, and you don't have driveability issues, you likely have enough vacuum for the brakes. If you have a Vacuum gauge, measure it.

[Bodied67]

Originally Posted by Accelo

Is your LS an automatic? Are you running the stock converter in the transmission?
If your converter is stock, and you don't have driveability issues, you likely have enough vacuum for the brakes. If you have a Vacuum gauge, measure it.

Automatic 4L60E with a 3k stall. LS1 w/ BTR hot rod cam. I do not have a vacuum meter to measure at the moment

[PbFut]

Buy a gauge. They are a valuable tool that will last 50 yrs if its a good one. My craftsman is past 40 yrs.
If that motor really needs a 3K stall converter, I question the vacuum it's able to create.

[LS short box]

Pic of my 67 Nova with manual brakes. It had stroked LS2/4L60E combo. Disc brakes front and rear. Adjustable prop valve. Stopped just fine just had to push the pedal a bit harder.
My go to guy for brake advice is Tobin at KORE3.com.

[Bodied67]

Originally Posted by LS short box

Pic of my 67 Nova with manual brakes. It had stroked LS2/4L60E combo. Disc brakes front and rear. Adjustable prop valve. Stopped just fine just had to push the pedal a bit harder.
My go to guy for brake advice is Tobin at KORE3.com.

we need more pictures please!

[MySons68C20]

More pics of that car please!

[71CHEVYSHORTBED402]

Originally Posted by MySons68C20

More pics of that car please!

That

[Bodied67]

Im gonna check what vacuum the motor pulls this week and go from there i suppose. A quick search says most boosters need around 15-20 to operate correctly if i can't get any of that i may just have to go manual. Any input on that figure of 15-20?

[dmjlambert]

I'm in the prefer manual few. When I converted my 1969 C10 to front disc brakes I used 1971 donor parts and 5-lug conversion rear axle shafts. I did manual brakes. The master cylinder bolts directly to the firewall. I prefer the feel of manual brakes. Rear brakes should be drum for the least troubles, based on threads I read on the forum it's just my opinion. If you go manual route you could probably get the correct push rod to attach to the brake pedal lever and the proportioning/combination valve from the parts section of the forum. Paid subscription to the forum is needed to post in the ads section, such as a want to buy ad for that, and it's a great way to get used parts.


http://www.67-72chevytrucks.com/vboard//showthread.php?p=9167631#post9167631

[Steeveedee]

Originally Posted by dmjlambert

I'm in the prefer manual few. When I converted my 1969 C10 to front disc brakes I used 1971 donor parts and 5-lug conversion rear axle shafts. I did manual brakes. The master cylinder bolts directly to the firewall. I prefer the feel of manual brakes. Rear brakes should be drum for the least troubles, based on threads I read on the forum it's just my opinion. If you go manual route you could probably get the correct push rod to attach to the brake pedal lever and the proportioning/combination valve from the parts section of the forum. Paid subscription to the forum is needed to post in the ads section, such as a want to buy ad for that, and it's a great way to get used parts.


http://www.67-72chevytrucks.com/vboard//showthread.php?p=9167631#post9167631

The interesting thing about standard power brakes on this era 3/4T and 1T trucks is that when the engine quits, after a couple pumps there is no boost. You're going to be standing on the pedal with both feet, then. I've worked on 60 series trucks from the early '60s that did not have any assist...just a single master. Now, a double master I can get behind!

[Bodied67]

Originally Posted by dmjlambert

I'm in the prefer manual few. When I converted my 1969 C10 to front disc brakes I used 1971 donor parts and 5-lug conversion rear axle shafts. I did manual brakes. The master cylinder bolts directly to the firewall. I prefer the feel of manual brakes. Rear brakes should be drum for the least troubles, based on threads I read on the forum it's just my opinion. If you go manual route you could probably get the correct push rod to attach to the brake pedal lever and the proportioning/combination valve from the parts section of the forum. Paid subscription to the forum is needed to post in the ads section, such as a want to buy ad for that, and it's a great way to get used parts.


http://www.67-72chevytrucks.com/vboard//showthread.php?p=9167631#post9167631

Tons of info in your thread. Thank you for posting that’s helps tremendously!

[Orange Crate]

If you aren't going hydro why not a vacuum tank/canister? Light weight and cheap. It's not like there is NO place to put it....

[LS short box]

Before some pics of the Nova.
1. Maybe just paint the booster a satin black so it isn't so in your face?
2. On one of my hot rod projects I tried using a vacuum canister. Didn't work well. Ended up putting a smaller cam so my power brakes worked well.
3. On a 66 Mustang project I did use a hydro boost from Hydratech. Worked really well. See pics.
So on to the Nova.
I'm a LS swap guy. I was surfing CL 10-12 years ago. Saw the add for the Nova. It was a no rust SS car. Original engine long gone. Original paint was poor. The PO had a somewhat local LS swap expert install a LS1/4L60E combo. The install was total garbage and the owner just wanted out. I made him a cash offer him couldn't refuse.
Pic of it on the trailer coming home. Pic of the engine compartment when I got it home. Still makes me chuckle.
Pic of it after the satin black paint job. Aftermarket front suspension. Four link rear suspension. C5 brakes all around.
Was a great project.