I just got back from AutoZone with the MC, booster and fittings.


The store I go to had the brake fittings behind the counter in the back of store. They also have 3/16 NiCopp tubing.
AGS PN BLF-39C-5 - M10x1.0x 3/16 bubble flare
AGS PN BLF-48C-5 - M12x1.0x 3/16 bubble flare

I'm getting the booster and brackets ready for paint.


Thanks Steve!

 

THANK YOU!!!

 

This is where we are. I didn't see the dust until the picture, sorry.
The city is coming down on me, so I'll run brake lines to the existing PV for now. That'll at least give me time to collect some parts. Yes, it'll work. I did mine in 1995 and never changed the PV. We WILL do it on Staytons truck. Yes, I'll have to re-break another set of brake lines. I see it as more practice.

 

That's not the adjustable brake rod is it?

 

Sorry Chris, its fixed.
How much adjustment do you need?

 

Well somethings not right. I was going to test fit everything in the truck before I painted the booster and brackets and found that the reservoir hits the booster.





What I got doesn't look like the AutoZone pic.




AutoZone PN 54-73112

Back to the parts store I go.....

 

When you got your booster, did you just order it under the generic number 54-73112 or, did you specify it for a '68-'72 model F350 with front discs when ordering it?

My dual diaphragm booster (donor originally came out of a '75 F350. I exchanged the core for a newly rebuilt booster), didn't have an adjustable input rod. It had a long, fixed length rod. I didn't know until sometime after-the-fact that the same basic booster was available in the '68-'72 F350 Bumpsides.

The main difference on them (compared to the Dentside version) is that they have an adjustable length input rod (input rod code FT8).

"FT8"code stamped on the input rod, where the adjustable eyelet screws in. This was on the rebuilt, dual diaphragm, F350, Bumpside booster I installed in my friend's '72 F100.







If you haven't already installed the booster, it isn't too late to take it back where you got it from and see if you can work with the parts counter person to get this version of that booster.

A rebuilt booster designed for the adjustable input rod will not come with the eyelet --I guess they assume you're swapping parts for parts and that you would just reuse the original eyelet off the booster being removed. If you didn't have the booster to start with, you'll have to come up with an eyelet from a donor or, machine/make your own.

 

Good info Ultra

I noticed the dot 5 brake fluid....

 

My bet is that that booster is for a Bullnose truck. I've seen a Bullnose with a dual diaphram booster that looks very similar to the Bumpside/Dentside F350 booster.

 

The stock brake valve on any '67-'72 F100-F350 is just a pressure differential valve. Its only mechanical function is to sense for a balance in pressure between the front and rear brake circuits. If the pressure isn't balanced, a spool inside the valve body will shift over and close the electrical contacts of the switch (sticking up out of the valve body).

When this happens, a ground path is completed through the body of the valve, through the chassis and back to the brake warning light on the dash. At that point, the warning light is lit up.



The '68-'72 F250/F350 trucks with factory front discs had the same style of pressure differential valve. The only major difference being that they also had a stand-alone metering valve to the front discs. The metering valve was mounted on the front crossmember, separate from the PDV.

Before 1973 though, no Ford truck came with a proportioning valve function. In '73, for an F100 - F350 2WD truck, the brake valves were integrated with 3 functions: Metering to the front discs, Pressure differential sensing between the front and rear brake circuits and a Proportioning function to the rear drums.

Example of the inner functions of a Kelsey-Hayes disc/drum brake valve for a 2WD truck under 6900# GVW.



Dentside 4x4s didn't get front discs until 1976. Prior to '76, the '73-'75 4x4s had a PDV like the Bumpsides.

 

I think I'll try to use the booster I have and go to a cast iron MC. The '95 Explorer MC looks a little too new for me. I also like this booster in that the cast iron MC won't stick out so far.
I used DOT 5.0 silicone brake on the highboy and it works great! You can make an absolute mess with brake fluid sprayed every where and not clean it up for days and it won't harm your paint at all. Ask me how I know. Silicone brake fluid will not harm buna-n, neoprene, viton or kalrez seal material. Its what Harley Davidson uses in their bikes. You do not want to mix glycol based brake fluid with silicone brake fluid. You also do not want to use silicone brake fluid in a vehicle that has anti-lock brakes, silicone brake fliud is too viscous.

 

....the option is always there to install a MC-to-booster spacer. I made this one out of 1/8" thick aluminum plate (this was on a Fox Mustang 5.0L dual diaphragm booster with an SN95 Mustang V6 MC). You would just need to extend the output rod outward by how ever thick the spacers is.

 

I used DOT 5.0 silicone brake on the highboy and it works great! You can make an absolute mess with brake fluid sprayed every where and not clean it up for days and it won't harm your paint at all.

Be very sure NOT to mix DOT 3 with it. Read the SDS for both and manufactures direction of use. I was just talking about this very thing with a marine buddy of mine that serviced the motor pool. I'm not sure if it this axact case, but the 2 fluid they used caught fire when heat was added.

 

When you got your booster, did you just order it under the generic number 54-73112 or, did you specify it for a '68-'72 model F350 with front discs when ordering it?

I went to that auto parts store "where they wear the yellow hat" and they couldn't hook me up. (I visited 3 other auto box stores) However, Prior Brake Rebuilders is here in dallas. I have their number so I can call them directly.

 

It's not Ultra quality, but it was good practice and mucho cussing. It'll do for now. I lost the banjo bolts and there were none to found at the box stores. Stayton will pick them up this morning, install brake lines to calipers and start a gravity bleed until I get home from work.