this may be a question for the expert (NumberDummy) -

I have a 1977 2WD F-150 w.power brakes (front disc/rear drums) and have just purchased a 1974 2WD F-100 w/manual brakes (front discs/rear drums). Is there any hope of the proportioning valve being the same for both vehicles? I'd like to 'convert' the 1974 truck to power brakes by taking parts from one truck to the other. Only thing worries me is that the inlets and outlets on the two might be different size threads?

 

I would not be averse to using NPT to NPT adapters.

 

If that's the only difference, I would certainly just leave the proportioning valve that is on the 74 there and just rip the brake pedal, pushrod, MC, booster and lines (pre PV) off the 1977 and if needed use adapters as you've said. I hate disturbing the proportioning valve on the 77. But there may be internal/hydraulic differences....??

 

F100's with standard equipment manual or optional power disc brakes makes no difference as to the prop valve. Only the years are specific.

D5TZ-2B257-B .. Brake Pressure Differential Proportioning Valve / Marked: D5TA-2B524-FA or FB

Applications: 1975/79 F100/150 2WD / 1975/79 F150 4WD / 1976/77 F100 4WD // 1975/79 F250 2WD w/single piston caliper disc brakes // 1975/79 E100/150 // 1976/79 F250 4WD // 1978/79 Bronco // 1979 F350 4WD.
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D3TZ-2B257-A .. Brake Pressure Differential Proportioning Valve / Marked: D3TA-2B524-AA

Applications: 1973/74: F100 2WD & F250 2WD w/single piston caliper disc brakes.

Be aware that 1973/79 F100/350's used TWENTY TWO different brake pedals, NINETEEN different power brake boosters, SEVEN different clutch pedals, I kid you not.

Differences: Series of trucks; With manual or power brakes; With front disc or drum brakes; With/without speed control; Before/from certain serial numbers.

Whatever booster you use must match the brake (and clutch) pedal, which have Ford ID engineering numbers stamped on them. Otherwise, ID'ing all these pedals would be impossible!

 

Thanks Bill,
I really appreciate the thorougness. So the best approach would either be to leave the thing alone or to take the complete setup from the 77, from pedal to proportioning valve. After the PV, should all be the same.

 

sorry, i accidentally hit the twice post. It's late and I'm a drinkin' now! Makers Mark (Kentucky-made). The best....Only Woodford Reserve rivals it.

 

Ford makes thing very difficult. Bill, not sure if you can help or not. I know you are the man for parts and their numbers, not sure about modifications. Here goes: I have a 75' F250 Highboy. It had drum brakes all around when I got it. Also, the brake pedal was firm at all times. However, I had the front axle changed out with a 79' Dana 60, Kingpin front. After the brakes were bleed, the pedal was firm. I drove it and about twenty mins. later the pedal started to fade. After sitting for a few days, it appeared to have some firmness back in the pedal. I thought the seal was bad in the master cylinder cap and decided to change the whole master cylinder. I bled it first, then bled the the brakes at each wheel bleeder. The pedal was firm with the engine off, but once I started it and hit the brake pedal, it went straight to the floor. I bled and bled and bled, all to know avail. Same result every time. I've read many forums and believe the problem to be air trapped somewhere. Before I bought the rebulit master cylinder, I never had that problem, with the pedal going to the floor at least. Not sure if the master cylinder I got was correct or not, due to the shear amount of choices. The one I got from O'Reilly is:
Cardone Remanufactured - Brake Master Cylinder

Part # 10-1388.

Is there anyway for you to tell me if I got the right one? I didn't see any numbers on the old master. The only number I saw was 264. Thanks for any help or suggestions.

 

the combination of booster / pedals and propotional valve, is unreal.

I took from a 1979 F350, booster and put it in my 78 F100.

the only thing that did not just bolt on, was the line. I had midas made me custom line, (took the actual brass fitting from the proportional valve and the booster, and had them made me new line)

After priming and bleeding, it work like a charm.

G

 

can a person replace the valve with an after market one?

 

BobbyShane: When you swapped the front axle did you change the prop valve?

C8TZ-2B257-B = 1968/75 F250 4WD-Use with drum brakes.

D5TZ-2B257-B = 1978/79 F250 4WD & 1979 F350 4WD-Use with disc brakes.

See post #4 for more D5TZ-2B257-B applications.

 

ok I will be soon in the same position bobbyshane is at .I did replace front axle Dana 60,rear disk swap,coming from a all drum truck on my 75 f250hb.I was going to maybe go with the prop valve that inline sells for Ford with all disks,it is metered for disk,will i also need an adjustable valve to dial in the rear brakes.hope all this makes sense thanks for all replys,really

 

I put a 77 f250 front disc on my 73 f250. I used the old proportioning valve but i had to cut the end of my break lines from the 73 and move them over to the newer 77. the 77 had bigger nuts on the end that didnt fit into the 73's valve. Its been about a year and it works just fine. I used a double flareing brake line tool. I would imagine working the other way around would work too. This could work for you too unless someone knows a reason why this is not a smart idea?

 

Can anyone help me out here,
Whats the difference between the pv for an drum/drum system thats 4x4 and 4x2? I noticed that the drum/drum 4x2 pv part number is C8TZ-2B257-D, and 4x4 is C8TZ-2B257-B...(I think)??? What are the differences, if any? Can they be interchanged (maybe NumberDummy can help me out here)? And are there any aftermarket solutions to bypass getting an original ford pv when overhauling the brake system? I would like to make my 1970 F250 manual drum/drum Camper Special an occasional driver and the HD drum/drum setup should do me fine, just wanna replace the old components.

Thanks,
Matt

 

Also, since I've read that the proportioning valve/distribution block on a drum/drum system sends the same amount of fluid to both the front and rear brakes, what does this valve actually do besides house the brake failure light switch? Is there anything really wrong with just plumbing your brakes straight from the Master cylinder to a front spliter that will then run two seperate lines to the front left & right wheel cylinders, and then to the spitter in the rear, since the warning light switch is broken anyhow?

 

Hi

it's really not recommended, however, you can do it. I ran my 77 for about 13 years without one of these valve, just put a splitter for the front and one for the back.

Just keep an eye for one of those valve at the wrecker, and when you find one, just replace it. If your the one pulling the part out of the truck, take the switch with it.

AGAIN, not really recommended.