how do I determine the right brake rod length
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- Posts: 123
- Joined: November 12, 2011, 4:52 pm
- Location: Colorado Springs,Colorado
how do I determine the right brake rod length
I'm trying to get some solid information on setting my brake push rod to the right length and can't seem to get any good answers.I swapped a 79 F-150 4x front end into my 66 F-100 4x to get the disc brake front end. I used a 69 Mustang M/C and the 79 prop valve. I just don't feel that I'm getting the braking power I should be and need some direction.
64 F-250 4x4 391 FT
66 F-100 4x4 352 FE
64 shortie 302/AOD
66 F-100 4x4 352 FE
64 shortie 302/AOD
Re: how do I determine the right brake rod length
Maybe your petal is too low. did you set the petal at same height? I had to cut the m/c push rod to match stock rod. You didn"t say if power booster was added. I used 68 mustang m/c and split front and rear brake lines to master cylinder. I have no power booster and stock 4-wheel drum brakes. Works good.
1966 f-100 ranger,red and white,240,cruiseomatic,3.00 gear,a/c.
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- Posts: 123
- Joined: November 12, 2011, 4:52 pm
- Location: Colorado Springs,Colorado
Re: how do I determine the right brake rod length
I didn't think to measure it before I did the swap so I don't know the correct pedal height. The m/c that I bought didn't come with a new push rod and the stock unit wasn't long enough at all. I didn't use a power booster, used a 68 disc/drum m/c and split the lines front and rear. It doesn't feel like it has enough without alot of leg, I checked the pedal ratio and found it to be low.
64 F-250 4x4 391 FT
66 F-100 4x4 352 FE
64 shortie 302/AOD
66 F-100 4x4 352 FE
64 shortie 302/AOD
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- Posts: 11470
- Joined: July 11, 2006, 11:28 am
- Location: Dove Creek, Co. elevation 6842
Re: how do I determine the right brake rod length
why did you not use the m/c for a 79 f150 4x4?
i have done the dual m/c conversion a few times with 4 wheel drum brakes and used m/c from 72 f250 4x4 with drum/drum, shortened rod from 72 f250 4x4 a hair under 1" and no problems.
maybe the m/c for the mustang does not have a big enough bore to push the fluid needed for the 79 4x4s disc brakes.
i have done the dual m/c conversion a few times with 4 wheel drum brakes and used m/c from 72 f250 4x4 with drum/drum, shortened rod from 72 f250 4x4 a hair under 1" and no problems.
maybe the m/c for the mustang does not have a big enough bore to push the fluid needed for the 79 4x4s disc brakes.
1966 F250 4x4
1964 Rambler Ambassador 990
Rest in peace departed Slick family members
Cam Milam
Lesley Ferguson
Steve Lopes
John Sutton
1964 Rambler Ambassador 990
Rest in peace departed Slick family members
Cam Milam
Lesley Ferguson
Steve Lopes
John Sutton
Re: how do I determine the right brake rod length
I have to use good leg pressure with mine. Might need power booster off of 79. The 68 mustang m/c bore is 1",should be large enough too push disc brakes on front. I would set petal height first for ratio. The push rod that i shortened about 1" like ICEMAN said. It was still longer than the stock rod. Or use 79 m/c with booster. Tony
1966 f-100 ranger,red and white,240,cruiseomatic,3.00 gear,a/c.
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- Posts: 579
- Joined: December 31, 2009, 5:26 pm
- Location: Saint George Utah
Re: how do I determine the right brake rod length
BTDT! I sawed the rods, drilled the pedal and generally screwed around with this issue for a long time. The right answer is to simply add 4 one inch spacers between the fire wall and step linkage. This deal is 100 % all Ford stuff except for the 4 spacers. I use the brake pedal from the donor truck (wide pedal), the brake support from the Slick, a gasket/firewall seal from Mustang, mechanical step bracket from the Donor (Ford), the booster (usually core this), and the master cylinder of your choice. I like the lines to exit the MC on the left and use a 1 1/4 inch diameter piston. If you have a hard pedal it is likley that you are using a MC with too large piston. If you peel your face off the windshield everytime you use the brakes likley you have a too small MC piston. Really all this is easy and all Junk Yard parts too boot!
William-in-St. George