Brakes not working!!!
Thread Starter
|
Junior User
Joined: Jul 2005
Posts: 74
Likes: 0
Brakes not working!!!
Alright this has been really making me mad so i need yalls help. I have 1996 f-150 with a 1978 F-150 front end. The calipers are from the 78, but the rotors, extended brake lines, and master cylinder are from the 96. after the swap i bled the system over and over myself and then i would get pressure in the pedal, but after about 10 seconds it was gone. So i took it to a local 4WD place called Extreme 4WD and asked them to check it out. they told me they got all the air out of the system and replaced 2 lines but were still having the same problem as me, the brakes wouldnt hold pressure. The master cylinder in new(rebuilt) so i dont thinks its that. So to anyone who has done a SAS or anyone who knows brakes, help me please!!!! I know brakes arent that complicated but im really getting frustrated. Could the different years of lines and calipers be the problem or maybe the 96 master cylinder isnt designed for those 78 calipers. I dont know. Mayb u guys could tell me what you did when you did your SAS. So any suggestions would really help.
Thanks,
Will
Thanks,
Will
Lead Driver
Joined: May 2000
Posts: 9,236
Likes: 12
From: Senoia, GA
sounds like you've got a leak somewhere, maybe not eben on the outside but maybe around the m/c pushrod or something.
if you pump the pedal will it hold pressure? maybe you're booster vaccum line got disconnected
-cutts-
if you pump the pedal will it hold pressure? maybe you're booster vaccum line got disconnected
-cutts-
Thread Starter
|
Junior User
Joined: Jul 2005
Posts: 74
Likes: 0
alright ive dun a little bit more research so tell me what yall think of this. the front end is off a 78 but the truck is a 96. I re used the 96 rotors durring the swap. On a 1978 f-150 the minimum thickness that the rotor can be is 1.12 in. On a 1996 f-150 the original thickness of a new rotor is 1.16 in. So with that info it would seem like these rotors would be fine but ive had the truck almost three years and ive never replaced the rotors. So i can assume theyve worn atleast .04 in. this would put the thickness of my rotors below the minimum requirement. I think that would be the reason i dont retain pressure, bc the piston in the caliper is fully extended and its not meeting with anything. that really is the only thing i can think off so does that make sense to yall or am i wrong?
Its Comin Right for us!
Joined: Feb 2005
Posts: 12,144
Likes: 2,633
From: GA
before i messed with that, i have one suggestion.
did u buy this rebuilt mastrer cyl from a parts house??
its not unlikely to get one that doesnt work right to begin with....it wouldnt hurt to tell them it leaks or somthing and try a new one ..just a suggestion
did u buy this rebuilt mastrer cyl from a parts house??
its not unlikely to get one that doesnt work right to begin with....it wouldnt hurt to tell them it leaks or somthing and try a new one ..just a suggestion
Laughing Gas
Joined: Aug 2004
Posts: 964
Likes: 1
From: Roseburg, OR
Do you know what the volume of the '78 calipers are vs. your '96 calipers? I'm thinking maybe the '78 calipers just hold a larger volume of fluid than the '96, and the '78 master cylinder was larger or had a longer stroke than the '96 MC. 
Trending Topics
i ain't rite
Joined: Mar 2005
Posts: 65,481
Likes: 5,542
From: Marlboro Mental Hospital.
the problem with that reasoning is that once the calipers are full, they do dot empty back to the master. so once the brakes are bled, you will only need a very small amount of fluid to actuate the brakes. the problem is it is loosing its pedal, which means air is being introduce into the system somewhere. it has to be looked at in a step by step process to eliminate each item.
disconnect the front brakes. will it work properly?? yes?? OK, the rear circuit is OK.
now hook up the front lines, but only the driver side. does it hold ?? OK the driver side is OK.
now disconnect the driver and hook up the passenger side. wow!! it won't hold pressure! looks like the passenger caliper or line is letting air in somewhere.
or, nothing i do will make this &^$##%^&%#$$# thing work!!!.
disconnect everything and plug up the master outlet lines. does it hold pressure?? oops, it was a bad master all along
sometimes it is the simple things that get overlooked that drive us crazy.
disconnect the front brakes. will it work properly?? yes?? OK, the rear circuit is OK.
now hook up the front lines, but only the driver side. does it hold ?? OK the driver side is OK.
now disconnect the driver and hook up the passenger side. wow!! it won't hold pressure! looks like the passenger caliper or line is letting air in somewhere.
or, nothing i do will make this &^$##%^&%#$$# thing work!!!.
disconnect everything and plug up the master outlet lines. does it hold pressure?? oops, it was a bad master all along
sometimes it is the simple things that get overlooked that drive us crazy.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Logistics Pro
Joined: Jan 2002
Posts: 3,739
Likes: 3
From: GANS
are you sure that the '96 master cylinder isn't for quick takeup calipers (ie calipers that retract more than .010 from the pads)? I know this is an issue with che*ys, but I am not sure about later model fords.
Thread
Thread Starter
Forum
Replies
Last Post
Firstford71
1987 - 1996 F150 & Larger F-Series Trucks
2
Jun 6, 2012 08:54 AM
broozerthehoundog
1987 - 1996 F150 & Larger F-Series Trucks
2
Feb 18, 2011 04:54 AM