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Old 07-23-2012, 05:18 PM   #1
67chevemall
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Brakes, check valve location?

To save some money I am going to try it w/o the master booster.

I have the port vavle and 4 check valves to put in.

Where do the check valves go? There is only one line going to the splitter on the lines, but I have 4 valves to put in.... 2 10psi for the front disc, and 2 2psi for the drums.

Do they go right before the wheels or do I have to run four new lines and place them by the master cylinder??

hummm...smoke break
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Old 07-23-2012, 05:40 PM   #2
68 short step
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Re: Brakes, check valve location?

not really clear on what you are asking, but the 2psi valves are for discs, and the 10 psi valves are for drums...typically you have 1 valve for the front (if discs, then it would be a 2psi valve), and for the rear you would have 1 valve too (if drums on the rear, then use the 10 psi valve)
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Old 07-23-2012, 06:00 PM   #3
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Re: Brakes, check valve location?

Quote:
Originally Posted by 68 short step View Post
not really clear on what you are asking, but the 2psi valves are for discs, and the 10 psi valves are for drums...typically you have 1 valve for the front (if discs, then it would be a 2psi valve), and for the rear you would have 1 valve too (if drums on the rear, then use the 10 psi valve)
oops got them backarsewards.

So just use one of each right after the master cylinder before the port vavle or after the port valve?
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Old 07-24-2012, 11:45 AM   #4
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Re: Brakes, check valve location?

Quote:
Originally Posted by 68 short step View Post
not really clear on what you are asking, but the 2psi valves are for discs, and the 10 psi valves are for drums...typically you have 1 valve for the front (if discs, then it would be a 2psi valve), and for the rear you would have 1 valve too (if drums on the rear, then use the 10 psi valve)
I looked at the packaging from the check valves and it says the 10psi is for the disc brakes and the 2psi is for the Drum...?

Anybody done this,, I am stuck!!

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Old 07-23-2012, 05:57 PM   #5
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Re: Brakes, check valve location?

Couple of pics while I plan the brake line attack.
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Old 07-24-2012, 03:03 PM   #6
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Re: Brakes, check valve location?

How did you get talked into buying all that crap?

To begin, the 10 psi is for the drum brakes you have on the rear. The rear brake system is unchanged so why would you need to add a resisual check valve? The fact is it probably already has one.
I say one, because no one ever puts more than one on the rear brakes. One brake line to the rear, calls for one check valve.

Those aftermarket check valves are usually used when the master cylinder is under the cab such as an early truck or a HotRod with nothing on the firewall. When the MC is below the wheel cylinders, if it's really low or parked on a hill, gravity pulls the brake fluid downhill out of the wheel cylinder into the MC. That pulls air past the lips of the wheel cylinder cups, into the system.

Before '67 most single MC's had a single check or residual valve inside the MC. In '67 they started using two residual valves inside the MC. I myself, have never seen a residual valve in a disc/drum or disc/disc MC. They rely on the spring and aluminum spreaders behind the rubber wheel cylinder cup to keep the lips of the cup tight against the cylinder bore.

If you have check valves in your drum/drum MC, you need to remove the one for your front brakes. Leave the one there for the rear brakes.





Probe the hole with a piece of wire or tooth pick. The valve is rubber and if you have one, you will feel it about 1/4" below the end of the brass tper fitting. Run a screw a couple of threads into the brass fitting and pry it out with two screw drivers. Throw the rubber and spring away and push the brass back in.
You don't need a thread cutting screw with real aggressive flutes which will tear up the brass. A smooth tapered thread will usually work fine.

What is a "port vavle" ? Any reason you chose an adjustable proportioning valve?

I see you are using the original steel brake lines to the rear of the front axle. Are you using extra long flex lines? The original drum flex line went to the top center of the backing plate. Turning the wheels left and right, meant the flex line only had to bend, not extend.
Can't tell from the pictures, so I'm sorry if I cover something you are already well aware of. The ca;ipers must have the bleader and the hose at the top.

I don't think there is a better or easier way to make your '67 conversion to discs than to use ALL of the forward brake lines and combination valve from a '70s truck. It's basically a bolt on deal. Just under the passenger side floorboard, in the frame rail, there is an inline coupling. That coupling is the same on the '70s Chevy truck. The worst thing you have to do to bolt everything up is drill a couple holes. The new combination valve mounts on the small cross member under the radiator and needs a mounting hole. That gets rid of much of the pipe clutter up by the MC and you don't have to bend and flare new pipe for the adjustable proportioning valve. The new flex lines are connected at the frame rail in front of the axle. My '67 already had small holes there. I just had to drill them larger.

My '67 truck is 3/4 and I used everything from a '76 1 ton (non dually). It even had a larger sway bar than the one I had taken from another 3/4.
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Last edited by RichardJ; 07-24-2012 at 03:28 PM.
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Old 07-24-2012, 04:30 PM   #7
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Re: Brakes, check valve location?

I don't want to get into how I got all this crap. CPP is the biggest collection of moron monkeys in one building I have ever delt with. They are great at wasting your money and time. BAN CPP. Even their packaging on the check valves is wrong it says 10psi for disc brakes...lol

Anyways
Thanks for your reply. I looked it over close last night. Thanks for the tip on taking the check valve out of the front on the MC. I'll take that out and the adj port valve has two front outs, which I'll run to the new flex lines.
The rear check valve I will use the OEM one and I'll put one 2psi check valve after the MC once I take the front OEM out of the MC.

Does this sound right?
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Old 07-25-2012, 03:36 PM   #8
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Re: Brakes, check valve location?

I put it all together and tried it out with the stock lines and proportioning valve. It worked but the discs stick to close to the rotor.

Tonight I will pull the oem check valve out of the front and install the cpp check valve.
They say 10psi on the discs but you say it is 2psi. either way it looks like I will have 3 extra ones.
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Old 07-25-2012, 10:18 PM   #9
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Re: Brakes, check valve location?

Not sure what is correct now. 10psi front disc or rear drum?

I posted a pic of the product.

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Old 07-31-2012, 03:03 PM   #10
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Re: Brakes, check valve location?

one 2psi check valve and custom fittings for the master and port valve did the trick

http://www.summitracing.com/parts/WIL-220-5248/
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