Recommended booster and MC 69 f250 drums

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papawhellie
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Recommended booster and MC 69 f250 drums

Postby papawhellie » Wed Sep 06, 2017 7:15 pm

I have read some and want to get what fits with best performance. Seems I want a dual diaphragm booster. Will the 54-73112 fit my truck? Does anyone have a list of the dual diaphragms. Looking at RA at f series trucks several options are there. I had read use a 72-73 booster as they were dual diaphragm. Should I pair the master with new booster or just use mine?

Looking to purchase soon. Pretty good price difference also from 70's to $100.

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Re: Recommended booster and MC 69 f250 drums

Postby papawhellie » Thu Sep 07, 2017 7:07 pm

I decided to order the 54-73112 from Summit. If it doesnt work out I can return it. The question now is do I need a larger or smaller bore master cylinder for 4 wheel drums? I read over that but do not remember now. I think my choices are 1 inch or 1 1/4 inch. I though it was said that the larger master puching greater volume was better for drums. I really do not know whioch requires greater volume, a caliper or wheel cylinder. I have a watch on a new USA made Napa/united on fleabay for 30 bucks shipped including rod. Might just go ahead a pop on it tonight if no one offers feedback. I replaced the master previously but dont remember the number. I should keep better records.
Mine pulls to the left when hitting the brakes with bad booster. Could it be adjustment? Guess I will tighten them and back off till almost scrubbing.

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Re: Recommended booster and MC 69 f250 drums

Postby Ranchero50 » Thu Sep 07, 2017 8:18 pm

Discs require greater volume. Typically the easiest upgrade is to pull the complete disc brake front assy off a dentside. You'll also get a anti roll bar and a chance to replace the worn bushings before installation.
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Re: Recommended booster and MC 69 f250 drums

Postby ultraranger » Fri Sep 08, 2017 7:27 am

If you are retaining 4-wheel drum brakes, you're probably going to find that the dual diaphragm booster is going to make the brakes very sensitive to applications of the brake pedal.

My truck originally had manual 4-wheel drums. In 2012, I added a '75 F350 dual diaphragm booster (54-73112) and a new 1.00" bore cast iron MC to the 4-wheel drum system. The brakes were very sensitive with this combination.

In 2014, I removed the front drum brake suspension and installed a '77 F100 disc brake front suspension and replaced the 1.00" bore cast iron MC with a 'modern' aluminum 1-1/16" bore MC for a '95 Ford Explorer (p/n M3246). The brakes work exceptionally well now.

If you're going to keep drums all the way around, you're likely better off with a single diaphragm booster.
Steve

1969 SWB F100 Ranger. 240-6, C-4, 9" N-case 31-spline Traction-Lok w/3.50 gears.

1968 Mustang. My high school car. Owned since 1982.

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Re: Recommended booster and MC 69 f250 drums

Postby xanthias » Mon Sep 25, 2017 6:34 am

I just installed a dual diaphragm booster and I can validate ultraranger’s comments. Dual diaphragm booster will literally give you feather touch at the pedal. If you’ve already gone that route and purchased the parts, however, one way to compensate for the over-boost is to fashion a vacuum restrictor in the hose that you will run from your intake manifold to the booster. That will lessen The amount of vacuum boost available and give you back some progressive pedal feel. That’s the situation I have.

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Re: Recommended booster and MC 69 f250 drums

Postby ultraranger » Sat Sep 30, 2017 10:06 pm

xanthias wrote:I just installed a dual diaphragm booster and I can validate ultraranger’s comments. Dual diaphragm booster will literally give you feather touch at the pedal. If you’ve already gone that route and purchased the parts, however, one way to compensate for the over-boost is to fashion a vacuum restrictor in the hose that you will run from your intake manifold to the booster. That will lessen The amount of vacuum boost available and give you back some progressive pedal feel. That’s the situation I have.


Another way to compensate for overly sensitive brakes is to go up in MC bore diameter. A larger bore MC will move more volume of fluid but will output less pressure, compared to a smaller bore diameter MC, with the same amount of force placed on the brake pedal.

However, too large of a MC diameter will make the pedal very stiff and difficult to apply sufficient force to bring the vehicle to a stop within a reasonable distance.

Drum brakes are self-energizing, disc brakes are not. Having self-energizing drums at all four corners, a 1.00" bore MC and a powerful dual diaphragm booster was not a good combination on my truck. Getting rid of the front drums and going up 1/16th of an inch in MC bore sizes from 1.00" to 1-1/16" (with the dual diaphragm booster) turned out to be an optimal combination in my truck.

The 1/16th inch increase in MC diameters reduced the overall output pressure by approximately 6%. The system no longer over pressures the brakes at the touch of the brake pedal and the linear brake modulation now is very good with this combination of components.
Steve

1969 SWB F100 Ranger. 240-6, C-4, 9" N-case 31-spline Traction-Lok w/3.50 gears.

1968 Mustang. My high school car. Owned since 1982.

2003 Azure Blue Mustang Mach1.

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Re: Recommended booster and MC 69 f250 drums

Postby papawhellie » Wed Nov 29, 2017 2:09 am

My brakes suck. I’m going to mess with them over Christmas break. I have to rebuild my front end. Changed radius arm bushings and took it to Columbus spring and they said replace main link and I beam bushings. Over 800 bucks. So I’m getting the parts at summit(better than rockauto because of shipping cost) and trying to install over break. Everything new including wheel bearings. After alignment hopefully the major break pull to the right can be diagnosed and re-bleed and take stock. I have to extend my mater rod a little as I don’t have the power I should. Got a rear driver wheel locking on hard press. So work to do...


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