65-StingRay

I 've got some logistical problems with swapping out my 65 master cyl. for the 67 dual master cyl.

If I replace the 65 master cyl. with the the 67 dual master cyl. (standard brakes) do I need to add the 67 proportioning valve and therefore the 67 rear brake line? I'm in the process of doing a body-off resto.

Do I need the 2 short proportioning valve brake lines from the master cyl.?
Has anyone got around this dilemma by not using the proportioning valve and just plumbed in new brake lines?
I'm looking for ideas. What have some of you guys done to get around this?

I know this topic has been covered in the past but if some of you could help here I would appreciate it.
I'll try and post a diagram of the 67 master cylinder showing the proportioning valve.

thanx

65-StingRay

67L36Driver

The "proportioning valve" is Not a proportioning valve at all but a hydraulic shuttle valve w/electrical contacts to indicate a loss of pressure in one end of the system or the other. If your wire harness lacks the provision for the dash warning light I'd just plumb around it.

Mine never has worked even though I've lost pressure in front/rear several times (calipers sucking air). I don't need an idiot light to tell me my brake pedal went to the floor.

Geek's 65

I changed mine over this last winter. Just plumbed it in - no valve - works great. I bought a new front to rear brake line because the end going into the master cylinder are a different size and I didn't want to use adapters. Same for the front line - bought new from the cylinder to the splitter block because of the different size going into the master. It'a a pain but certainly worth the peace of mind knowing the system is split rather than a single point of failure. I know someone makes a kit with the two lines from the master and the new front to rear but I can't remember who it is.

Warning - there is a guy on e-bay who sells a front splitter block and the two lines from the master cylinder. It is described as letting you use your stock lines from the splitter. Isn't so. That splitter block is not like he says it is and you wind up not only needing a new front to rear but also a new block to left wheel line. I found out the hard way.

Good luck

Geek

66BlkBB

When you purchase the 67 master cylinder you do not get the electric shuttle. No need to purchase it if you are not going to use it. No need to plumb around it. While the 66 master cylinder was being rebuilt on mine I purchased a 67 to install so I could drive it. Simply bolted it up after bench bleeding it. Then bled the system. Only trouble you may have is the threaded ends on the lines. In 65 they had some different sizes than they did for the 66 power brakes. Don't know if that carried over to your car or not. Was yours an original J50 option? Or are you converting from non power to power now? J50 option in 65 has different size threaded ends than 66 so master cylinder is different even though they look the same. I don't see any other problems as long as the original brake lines are long enough to reach the 67 master cylinder.

Had mine all written and Geek took my thunder. How you doing Geek??? I will agree with you on the simple exchange of the master cylinder. I did not know that someone was making the change kit for the lines on this conversion.

Steve

Tom/99

That sounds like a lot of work. Why do you want to put a 1967 master cylinder on a 1965? The master cylinder on my 1965 works just fine.

StrayDog

I converted my 1966 Non Power brake, to dual chamber 1967 master cylinder & 67 booster, last winter.>>> works great & looks great, actually bought the 67 MC for 20 bucks at NAPPA......The brake line conversion kit is available from Corvette stainless brake in Miami, it comes with a special brass block (for front lines) & new front line to mc ......it also comes with a new rear line...but I gently bent the rear line up & used brass fitting adapter for rearport on MC...if you want photos semt me your email address ....worked for me ..the Dog............

Tampa Jerry

I did the change over on my 66. Dean at Hot Rods USA set me up with everything including a power booster. He was way less expensive than any of the vendors. His shop is in Washington state. Easy to deal with. In addition to the kit I got from Dean, I had to purchase two brass blocks. You will need drivers side front and rear blocks. The standard 66 line joining the front and back is 3/16", the 67/68 line is 1/4". Dr. Rebuild had the blocks. Let me know if you need Dean's number etc. Jerry

Geek's 65

Tom - Mine did too. I rebuilt the brakes a couple years ago and that was one solid pedal when I was done. But later I was driving a friends 69 and lost the right rear brake caliper. It blew fluid all over the rear but the car stopped with just a little more leg power using the fronts. If that had been my 65 I am convinced I would have had no brakes even if I had pumped the pedal fast. So I went to the 67 split system.

Steve I am doing well thanks. Looks like I get to retire in 97 days. At least from this job. Then it will be on to other things. That supposed brake adapter kit cost me $70 plus shipping. If it had worked as advertised that would have been the bomb. But it didn't. Doesn't. And won't. No I didn't get my money back either. It was a "well you can just get a new line for the left front and then just add a little bit to the rear line to get it to hook up and it will be OK." Take care.

geek

LB66383

I agree with "Geek." I lost the right rear line in my '66, non-power single master cylinder and had zero brakes. Fortunately I was going slow, but still ended up in the middle of the intersection before getting stopped with the parking brake and shutting off the engine. Needless to say, I converted to the '67 dual master cylinder. I bought a conversion kit that includes the master, lines, shuttle valve, distribution blocks, etc. It was a fairly easy conversion, I didn't use the shuttle valve, just plumbed straight to the master.

toddalin

To tell the truth, I'm not so sure that a dual M/C would work on either set of axles if you loose pressure at any point. Case in point.

My '64 has disk fronts and drum rears with a '70s manual dual master cylinder. The brake lines to the front and rear circuits are totally separated with no distribution/warning light block between them. The front line comes out the front port of the M/C goes to the line lock then the calipers. The rear line comes out the rear port, goes through a 10# residual valve, an adjustable proportioning valve, then to the rear wheel cylinders via the rear distribution block.

At one point my front brakes developed run-out and started sucking air. I was on the freeway at the time. When I came off the ramp..., no brakes front or rear (or so it seemed). (Gotta love those nice big '63/'64 parking brakes in the rear! ) Only needed to fix the front brakes (new calipers and rotors turned) to make the whole system work again.

65-StingRay

Tom/99 as some of these other gents have mentioned ... with just a single master cyl. your vehicle becomes prone to losing all braking if something happens to any part of the brake system. With a dual system ( as became regulated in 1967) you should not lose braking to both sides, but only 1 side, either the front or the rear. It becomes a safety issue. That's why Im swapping.

Thanks for the good advice guys. I'll see if I can track down a vendor that sells a complete kit. If not I'll just track down the parts and bend the lines myself. It's a good thing I bought that bending and flaring tool a while ago.

65-StingRay

Geek's 65

65 - Went back through my receipts. Eckler's is where I found mine. In the latest catalog it's $129.99 for the front to rear line, front to front block line, new front block, and new rear block. The front and rear left to right crossover lines from 65 worked fine. Part number is 46128.

Geek

RDaddi

Changed to dual power 9 in ,used a wilwood valve for the rear about $35