1970 F250 power disc brake lines

[CobrajetF-250428]

I want to replace the brake lines on my 70 F-250 with factory power disc brakes. The problem is nobody sells a pre-bent brake line kit for my truck. I have tried LMC, N.P.D and Inline Tube The closest match is one for a 70 F-250 with power drum brakes. The schematic on this sight seem to show all the lines and distribution block item number 2B257 being the same, only difference being the front hard lines along with the proportioning valve 2B161. Am I right on my assumption that using the pre-bent lines for the power drum brake application (sans front brake lines) would work. Also am I right on 2B257 being the distribution block/safety switch and 2B161 being the proportioning valve? Any and all help would be appreciated............Thanks

[ultraranger]

The valve inside the left frame rail, right behind the steering gearbox, is a pressure differential valve. The small valve on the front crossmember, splitting off to the front calipers, is a metering valve.

Bumpside F250/F350s with factory front discs didn't have a proportioning valve. When front disc brakes became standard on all 2WD F100 - F350s in '73, the brake functions were all combined into one brake valve assembly: Metering to the front discs, Pressure differential sensing between the front and rear brake circuits and for the first time, Proportioning was added to the rear drum brake circuit.

Reseal kits are available for the Bumpside pressure differential valve from Muscle Car Research.

[CobrajetF-250428]

Thanks for the reply Steve, the info is definitely helpful. Since reading your reply I found out there is also a tool that NPD sells to keep the piston in the differential valve centered while bleeding(otherwise brake light on dash will come on like mine does, brightly I should add) and that the metering block is supposed to be depressed to let fluid flow through the lines before the bleeding process. Since your the only one to offer help with a reply can I contact you privately if I need? Oh have you ever rebuilt on of these differential valves and if so is it as straightforward as shown in the "Muscle Car Research" instructions show? Since doing a complete brake job on my truck including new power booster and master cylinder ect. I am surprised how good my brakes work considering the lack of focus givin to the subject of this post

[71Fe2O3]

I don't know about pre-bent lines. When I did my brakes I used lines made from a copper-nickel-iron alloy. They are more expensive but much easier to flare and bend than steel lines, and they don't rust. You can find them at NAPA and Amazon, probably many other sources. A 25 foot roll should be enough for one truck plus some extra to learn with if you are new at working with brake lines.

[colnago]

I got a 25' roll from Eastwood. Found it was enough to redo the front. I put my prop valve right below the MC, and bypassed the distribution valve on the frame. This was for a drum-to-disc conversion. You can find a fixture that prevents the shuttle from moving back-and-forth, so you can bleed the system. Just an FYI, there are multiple sizes, so be sure of your valve threading before ordering (I think the original is smaller, and the newer brass valve is larger).

Joseph

[lloyd70cs]

May I ask how you are converting to disc brakes. I've been researching this and am a little confused by the information. From what i have read the "easiest" method is to swap a full i beam set from a donor truck from 69-78 with disc set up. I did some measuring and the only difference I measured was the distance from I beam retention bolt to bolt was off a quarter inch. The distance from the i beam out to the king pin location and back to the radius arm bolt was identical. The only thing i couldn't measure was the king pin itself. Doesn't that mean I could just buy a new spindle for a disc set up and go from there? new master cylinder and proportioning valve too.

Lloyd

[Ron_Hall]

May I ask how you are converting to disc brakes. I've been researching this and am a little confused by the information. From what i have read the "easiest" method is to swap a full i beam set from a donor truck from 69-78 with disc set up. I did some measuring and the only difference I measured was the distance from I beam retention bolt to bolt was off a quarter inch. The distance from the i beam out to the king pin location and back to the radius arm bolt was identical. The only thing i couldn't measure was the king pin itself. Doesn't that mean I could just buy a new spindle for a disc set up and go from there? new master cylinder and proportioning valve too.

Lloyd

Lloyd, really good read here(2 page):
http://www.fordification.com/tech/discbrakes01.htm

Ron

[lloyd70cs]

Thanks Ron,

I've looked at that article. I have a 1970 F250 Camper Special 2wd. Is it not possible to take a disc spindle from any year and have a king pin machined to specs for cheaper and less work?

[Ron_Hall]

Thanks Ron,

I've looked at that article. I have a 1970 F250 Camper Special 2wd. Is it not possible to take a disc spindle from any year and have a king pin machined to specs for cheaper and less work?

When I look at the article it looks possible but I'm new to this also.

Ron

[lloyd70cs]

i picked up all the parts off a 78 the other day for this conversion. Will need to order bushings set and booster. also rotors aren't worth keeping. basically got spindles and I beams. also got the power steering setup except forgot to get the column!.

any tips on which tools were most useful to have. the owner of the parts truck was a true gentleman and spent a week soaking the bolts so it wasn't a killer.
Thanks

lloyd

[colnago]

I pulled the caliper brackets and dust shields off of a bump in the junk yard (don't remember what year). Those are the only things you cannot buy new/rebuilt. I kept my I-beams, spindles, and brake pedal/bracket, bought a vacuum booster for a '67, and MC, rotors, bearings, pads, and calipers for a '68. I bought one of those brass proportioning valves (PV2?), and bolted it all together. I still have a leak somewhere, because the fluid level keeps going down, but the brakes themselves work great.

Joseph