disc brake conversion question?
Posting Guru
Joined: Jun 2007
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From: Butler, IN
i can see what every one is thinking on the keep it all the same when your doing an easy swap like that but what about the guys (like myself) that are doing the CV front end swap into my 65 what do you do for the power breaks on that i was planing on taking the master cyl off a late 70s truck and fitting it on mine and using an adjustable proporting valve
Look closely at post #131, #134 & #135. This is the way carcrafter22 is doing it. I can't wait to see more pictures of your project, too.
Post Fiend
Joined: Nov 2000
Posts: 6,060
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From: Glendale Arizona
i can see what every one is thinking on the keep it all the same when your doing an easy swap like that but what about the guys (like myself) that are doing the CV front end swap into my 65 what do you do for the power breaks on that i was planing on taking the master cyl off a late 70s truck and fitting it on mine and using an adjustable proporting valve
Its called Crap out of luck as you are 100 percent on your own as to engineering calculation of bore displacement,design and stopping pressures needed. No one can give you an accurate guess as to what you need, and would be quite inviting of a suit giving that kind of advice... Which you may follow or not follow and run over a passel of nuns.... Persons need to remember the ramification's of their re engineering actions.
Some one once calculated the force deposited on the MII's stock rear radius arm at over 30,000 pounds of force during hard braking......Most modern cars produce even more, transferring it to the chassis...... something to think about, a real welding litmus test on those 110v 90 amp mig gussets....
On a Slick or Bump conversion it is imperative the intermediate cross member is in place as it absorbs and prevents deflection, the braking loads delivered by the radius arms and transfers it equally through the rest of the chassis.
Garbz
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Joined: Feb 2007
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From: Pittsburgh,Pa.
That would have to be one heck of a large booster! I put a 70 cab on a 79 4 X 4 chassis. I retained the original large 79 booster and bolted it to the 70 cab. It has a 460 and there is plenty of clearance. It doesn't have a body lift either. Maybe it is a problem with 2wd, or the 460 isn't installed correctly. I dunno, works for me!
Posting Guru
Joined: Jun 2007
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From: Butler, IN
Putting it this way.....Extreme braking - intermediate cross member = collapsed frame or worse. Is this correct?
Posting Guru
Joined: Feb 2007
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From: Pittsburgh,Pa.
I'll do a bit more research and see what I come up with.I do remember it being a 4x2 truck.
Elder User
Joined: Feb 2006
Posts: 788
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From: Cascade, ID
master cylinder
I thought I remembered something about there being a check valve in the drum brake master cylinders that needed to be removed to use it with disc brakes.......... It has been along time since I have researched brake swaps though, maybe it is just a pigment of my imagination........
I personally would take the entire setup from the donor rig, save yourself a bunch of head aches later on. People pay good money for "engineered" kits, isn't a set-up off of a donor basically a kit? It may be better than a kit though, in the fact that you get to see it installed, tear it apart, and put it back together....That way you already have some experience with how it goes together.
I personally would take the entire setup from the donor rig, save yourself a bunch of head aches later on. People pay good money for "engineered" kits, isn't a set-up off of a donor basically a kit? It may be better than a kit though, in the fact that you get to see it installed, tear it apart, and put it back together....That way you already have some experience with how it goes together.
Post Fiend
Joined: Nov 2000
Posts: 6,060
Likes: 7
From: Glendale Arizona
If it is not there it will allow the frame to deflect, in effect bow inward at the bottom and outward at the top...This can cause all sorts of weird issues, Sudden camber change and inability for the wheels to center naturally as designed and worst of all allowing stress causing the frame to fail. You could also feel the cab suck downwards on the mounts as they are pushed outward and down... That would be a creepy feeling.....as the cab fell off with you still in it... Don't laugh i know someone who went up a bank (78 F150) doing evasive maneuvers to miss a crash and the cab ripped/fell off the truck....(only in the rust belt)
The load is transfered to the frame section but it cannot absorb it to the remainder of the frame.. Ford trucks are riveted to allow a little flex and absorb this.
This is for the twin i slicks bumps and dent trucks only with added discs for stopping, or even a good set of drum brakes.
Garbz
The load is transfered to the frame section but it cannot absorb it to the remainder of the frame.. Ford trucks are riveted to allow a little flex and absorb this.
This is for the twin i slicks bumps and dent trucks only with added discs for stopping, or even a good set of drum brakes.
Garbz
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Posting Guru
Joined: May 2005
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From: Spokane, WA
A master cylinder off a truck with four wheel drum brakes will NOT work on one with disc brakes. Four wheel drum masters use a residual pressure valve in the outlet ports which are designed to keep tension on the return springs in a drum brake system so there is not a delay in stopping time when applying the brakes. Use of a drum brake master on a disc system will cause the front brakes to drag. You definitely need a disc brake master cylinder as well as a proportioninig valve.
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