4 wheel disc upgrade

[67f250_irv]

Hello all...
I have a 67 F250 I am restoring from the ground up. I have already installed the front disc setup from a newer f250 truck (by the way, my truck needed different spindles...the bearing diameters were different on the outer bearing)....anyway... I have located a disc conversion kit for my Dana 60 rear end. My question concerns the master cylinder and proportioning valve. What do I need to get? My understanding is a stock drum/drum truck does not have proportioning valve, it has a distribution block.....correct? If it is a distribution block, it should be able to stay correct? The mater cylinder has different ports for the front and rear right?? I guess the distribution block keeps the rear line seperat? Long story short...I am guessing I need a new master cylinder for Disc/drum with a new proportioning valve so I can adjust the rear breaks correct? I am also hoping the stock drum/drum break lines will work, since I have brand new stainless lines already plumbed.
Sorry for the lengthy post, but want to confirm my thinking.....THANKS!!!!

[Banjo]

I for one, am lost, are you going 4 wheel disc or disc/drum or drum/drum or ?

[Banjo]

BUT, I think what you're asking is that you have a new drum/drum master and lines and you'd like to keep all that setup for disc/disc, which I'd think you could. The portioning valve deal is to blend disc/drum, so if you went one way or the other (all disc or all drum) you don't need a portioning valve, I don't believe. However, you could always install one of those hot rod inline jobs where you just turn a knob to change bias of fluid distribution if you experience premature lockup at one end or the other.

[67f250_irv]

Sorry my post was confusing....I don't have a new master cylinder yet, but I do have the lines already installed. Yes, I am going with 4 wheel disc. Just trying to figure the best route for master cylinder and proportioning valve, if needed.
Thanks....

[FORDification]

To go with 4-wheel disc brakes, you'll need a master cylinder specifically made for them. You can't (shouldn't!) use a disc/drum or drum/drum master cylinder. You won't need a proportioning valve, but I'd definitely suggest plumbing in a manual adjustment valve in the rear brake circuit, so you can fine-tune the front-to-rear brake bias.

As you stated, the drum/drum setup simply uses a distribution block which also has a built-in pressure switch, which will light up the interior warning light (on the dash, above the parking brake) if either the front or the rear brake circuits lose pressure. You can use it if you want to maintain the warning light function, but it's not necessary for the brake system.

What setup are the new stainless lines for? I'm gonna guess they're for a disc/drum setup? If so, they're probably not going to work without modification, and those stainless lines are a major PIA to modify, since they're so hard. You can't re-flare them with standard flaring tools.

However, if you want another unsolicted opinion, I'd have to suggest not bothering with a 4-wheel disc setup at all. IMO a properly setup disc/drum system will be more than adequate on a truck...especially if you install a Hydroboost instead of the vaccum-assist booster. (Do a search for 'Hydroboost'..it's been discussed a number of times.) A Hydroboost with a disc/drum setup will outbrake a 4-wheel-disc setup with a vacuum booster.

[Galaxie64]

Even with 4 wheel disc I thought you still want more braking to the front than the back, a la a proportioning valve.

[FORDification]

You're correct...you should have a proportioning valve. I meant you don't want the FACTORY proportioning valve. However, what we're calling a "proportioning valve" here is actually a 'combination valve'...it's meant for a disc/drum setup, since the two have completely different characteristics, and has three components: a proportioning valve, a metering valve and a pressure differential switch. It's the metering valve that we really need when converting from a drum/drum setup to a disc/drum setup.

Read the info on the following link...it should help you understand all this, and they do a better job of explaining it than I do:

http://auto.howstuffworks.com/master-brake2.htm

[460 crew]

I have 4 wheel disks now and running the 78-79 f250 4x4 proportioning valve and matching master cylinder and my smaller 7in dia booster. Everything works in harmony.

[cdeal28078]

Can you really tell the difference with the rear disc brakes. Does it stop that much better or is it more for a looks thing. My f100 with front discs stops so good if it were much better my chrome would remove itself on a hard brake.
Clint

[460 crew]

I noticed a big difference but then again i'm stopping a little bit heavier of a rig, 4x4 crew on 35's. I kinda thought it was in my head but I had the GF drive it and she was impressed.

Like your saying you might not have that much to gain over what you have with an F100 in it's current state.

Tell you what ppl notice them and are like WTH you have 4wheel disks I don't even have that on my new Che**. LOL