I've been posting on and off over the last couple years about bad brakes on the F150's. I had replaced everything except calipers and flex lines. I, finally, replaced the calipers and it made a BUNCH of difference. I got the steel piston calipers(I didn't look at what was in the original ones though)from Kragen Auto parts for less than $25.00 each. Now when I first apply the brakes they feel about the same as before which was OK unless I need to stop a little quicker then it was a waste of time to push any harder and if I had even an empty trailer it felt like it wasn't going to stop at all. Now they feel a WHOLE lot better. I actually have the illusion of control! I still want to find out why the rear brakes work so crappy but I'm a lot happier with the overall braking.

JohnF

 

have you adjusted your rear brakes lately? my adjusters are broke, and if i dont adjust them every so often, i don't stop very well at all

 

John,

Do you have power brakes?

 

I know where this is going so here is the basic info.

Everything in my brake system except the lines are now replaced. That includes the booster, mastercylinder, proportioning valve, slave cylinders, some springs and misc and now the calipers. The brakes have not been satisfactory for years and nothing improved them until I finally replaced the calipers themselves. I know everyone would have suggested replacing the booster/mastercylinder assembly, did that 3 times complete and 3 or 4 more times mastercylinder only. The rear wheel cylinders were frozen solid the first time I replaced them and, after replacement, even that didn't make much difference so I replaced the proportioning valve. That was a waste of money as well as a major pain in the butt. Yes, I had the brakes pressure bleed but it worked no better than when I and my son did it aprox 3,000 times. I've been down every road most of you can think of/suggested and it's taken me around 6 years to come up with any great improvement. I am running 33" tires now BUT the problem did not change when I put the bigger tires on. I noticed almost no difference in brake performance either before or after. I replaced the rear end with a 9" about 2 months ago and went through the brakes before transferring them to the new rear end, the wheel cylinders were stuck again but not corroded solid like last time. That tells me the rear wheel cylinders are not seeing much, if any, use. The original rear shoes I finally replaced at aprox 160,000 miles, when I replaced the wheel cylinders the 1st time, and they weren't worn out but I had replaced the front pads 1/2 dozen times and the rotors once.

If the, above, narrative seems a little like a bunch of sentences stuck together it's because I'm at work and keep getting interrupted mid type...........I give up, here's the post

JohnF

 

When you did the calipers ,I hope you put on new hoses. Also adjust rear brake shoes way up tight until wheel won't move then back off till it does then bleed them out. Then make sure theres pressure back to the rear brakes by turning wheel and appling brakes and make sure they work. I just got though doing 1982 F-50 fwd. The rear brakes weren't working at all.

 

That's what I'm saying about the rear brakes. I've never worked on one, older ones, where the rear wheel cylinders weren't frozen. My rear brakes will stop the wheels when the rear is in the air but in actual use they don't appear to do much of anything. I know the brake bias is set up so the rear wheels won't lock up before the fronts but the rears should do some work. It appears to me that the setup is a little too weak in the rear. I'm tempted to shim the master cylinder piston just slightly to give a bit more fluid volume to the rear or to look into one of the mechanical linkage proportional setups that adjusts the rear bias by the relative distance between the frame and axle. I think some of the older 3/4 ton trucks had those that lent more pressure to the rear brakes if there was a load in the bed.

JohnF

 

Have you looked at the depth that the push rod on the booster is set to. Most books give a depth of .980-.995. Too short no or bad breaks. Too long and TOOOO much breaks. Also I would look at the peddle and it's mount!

 

I wouldn't stop trying to fix rear brakes. If you don't get a steady strong brake fluid flow when bleeding, keep trying.:-staun