I converted my manual front drums to disc brakes, on my 68 bird, rears are still drums. I did not notice a big difference in braking distance. I beleive I need an adjustable proportioning valve. If so how do I install and adjust it? and what brand is good?

I converted my manual front drums to disc brakes, on my 68 bird, rears are still drums. I did not notice a big difference in braking distance. I beleive I need an adjustable proportioning valve. If so how do I install and adjust it? and what brand is good?

You need to see if your rears lock up excessively first. If not, I would leave alone.

leave it alone meaning dont put a proportioning valve in?

what the prop valve does is prevent the front brakes from applying until the rear drums are applied.

this keeps the car from nosediving during braking applications and also provide a safer stop in slick conditions.

if the braking distance hasn't changed much i'd look at other possible issues with the system first.

post what you used to convert this car over to discs [system or peices] and maybe we can provide a solution.

there are some members who have done a conversion and not used a prop valve. they're happy with the way their car stops but i wouldn't recommend this.

mike

I just did the same thing on my 68 bird. I converted from drums to discs in the front as well as changed the m/c and added a booster. I used a booster, master cylinder, and proportoning valve from an 83 camaro. Mine isn't stopping perfectly yet either, but I still need to make sure that I have all of the air out of the lines as well as make sure the back drums are adjusted correctly. I'll keep you posted on how that works out.

What Mike Nixon said.

mr. nixon described a metering valve, not a proportioning valve.

most FGFs did not have a proportioning valve, which reduces pressure to the rear brakes on hard stops. Birds with A/C and disc had them. All FGFs with front disc had a metering valve, which delays front brake action as described.

a combination valve may have either or both of these functions. They were separate on the FGFs.

Metering valve Meters fluid flow to the fronts

Proportioning valve reduces pressure to the rear in Proportion to the front.

Thanks Scott for the elaboration.

I have a terrible habit of using the term "proportioning valve" as a general statement similar as saying "Kleenex" for tissues and assuming people understand what I mean. http://forums.performanceyears.com/g...n_rolleyes.gif

Dammit man! Listen to what I mean, not what I say! http://forums.performanceyears.com/g.../icon_wink.gif

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by PMDRACER:
Thanks Scott for the elaboration.

I have a terrible habit of using the term "proportioning valve" as a general statement similar as saying "Kleenex" for tissues and assuming people understand what I mean. http://forums.performanceyears.com/g...n_rolleyes.gif

Dammit man! Listen to what I mean, not what I say! http://forums.performanceyears.com/g.../icon_wink.gif </div></BLOCKQUOTE>

what pmdracer said. http://forums.performanceyears.com/g...on_biggrin.gif

mike

replying to mr nixon, I purchased the conversion used but new condition and dont know if it was specifically for this vehicle or not. It came with a booster that I never used. Althought I bought a new dual master cylinder, I dont know if it was for manual(what i have now) or power? How can i tell what this master I have now is for? Power or manual. I still have the booster and was thinking of putting on. Ive had this set up like this for 7 years now. Iam starting to think of the safety factor of being able to stop quicker!

67-68 birds with manual brakes used the same masters as the ones with power. 69 disc was power only.

power brakes or disc brakes in themselves will not decrease stopping distance, but disc brakes decrease brake fade.
Additionally, proportioning valves or other balance valving will not decrease stopping distance either, except by maintaining stability. Balance valving keeps the car balanced by decreasing fluid flow or pressure to keep wheels from locking early, and maintaining stability.

power brakes decrease pedal effort.

if you have single piston, 2 15/16" calipers and 11" rotors, i would recommend an 11" power booster, and a 1.125" master, because that is what the factory used on these cars.

the balance valving is most useful in the snow. under normal/dry conditions, it is not very useful on this specific application.
if you tend to ride the brake or do light stops, a metering valve up front will help get more use out of the rears.