Pirate 4x4 banner

Caliper Misconception: Ford 1 or 3/4 ton dual piston vs GM 3/4 ton single piston

9K views 12 replies 8 participants last post by  Cochese 
#1 · (Edited)
I have been doing some research and reading on here the past couple of days because I am considering dumping my front stock Ford Dana 60 dual piston (78/79) calipers (which I have run for years) for the more common/compact GM 3/4 ton option (with a custom bracket of course). This change is due to the front needing a rebuild anyway and my disdain for the Ford method of retaining the caliper (never fallen off but I have sheared the retention bolts/rubbed wheels on several occasions). From what I read, many people say that it would be a mistake to go to the GM stuff because my stopping performance would be reduced. The handy table I found on here states that the total piston surface area of the Ford caliper is ~7.46in^2 (via 2 smaller pistons) and the GM is ~7.77in^2 (with 1 large one). If I am running an appropriate master cylinder (1978 Mercury Marquis 1 1/8" bore in this case on a YJ), why would the braking be reduced if the surface are is only a bit more? Is there another benefit to the dual piston I am not seeing? Spread out pressure on the pads perhaps?
 
#4 ·
you got a few things wrong.
'ford retention method' is the first one. used by all the big three and others, more likely a bendix design that works far better then the crap caliper guide pin you want to switch to
MASS is very important in brakes.
yes dual piston calipers will spread the force over the pad better then a single.

you definitely broke myths that no one else has pondered
http://www.pirate4x4.com/forum/jeep-hardcore-tech/851498-info-calipers.html
 
#8 ·
How is the "crap caliper guide pin" worse then the H-block w/ leaf spring w/ single bolt design? I was not aware that this was used anywhere else but on Ford 1 ton D60 and 3/4 ton D44 (4wd and 2wd) from the late 70s/early 80s. I found that link below previously (awesome chart that I drew my piston area from) and it has nothing to do with my question about preference for Ford dual piston instead of GM single that has greater surface area. Plus I needed to add to my post count :flipoff2:
 
#5 ·
It's all about surface area of the piston/pistons. Ford dual piston surface area is approximately 7.46 square inches VS the GM 6.787 square inches almost a 10% reduction in brake force. This does not take into account any other factors, you'll loose 10% right off the top. Doesn't seem like much but it is very noticiable IMO.

The larger the surface area of the piston the more stopping power you have for the same input.
 
#10 ·
ive got a question. im no math genuis but on every chevy brake setup ive had (3/4 or 1 ton) the top and bottom of the piston doesnt even hit the pad. does that effect what your trying to say here. the ford caliper seems to put more pressure on the overall brake pad surface.oand has more contact to the back of the pad which would have less deflecting if any due to vibrations. i noticed a differace when i switched.
but again im no genius. just did what others said work
 
#13 ·
Thanks for the info on the Dodge/GM stuff. I think I will give the Ford calipers another shot (after I replace the caliper bracket) with a hardware rebuild and focus on the booster/MC.........thinking 1995 YJ dual booster with 2000 Dodge 2500 MC to replace my 1978 Mercury Marquis.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top