1990 F150 5.0 extended cab

The pickup is running better thanks to help from this forum. Still has a high idle (~2000 rpms until warmed up) and has a helluva time staying above 55 mph.

However, I think my next step is to get this brake issue sorted out. It's my understanding that there is only ABS on the rear brakes right? The pickup sat for four years with the left rear brake off. I put in a new cylinder on that side along with new springs and shoes on both sides. Then bled both rear brakes until new clean fluid had replaced all the old stuff, didn't touch the fronts.

1. When stepping on the brakes I get some stopping power but it's not until I get to the bottom of the travel when the fronts kick in that any real stopping power is applied. This is fine on dry roads, but on ice/snow the fronts lock up before the pickup even thinks about slowing down and I don't seem to get any help whatsoever from the rears. Luckily I can handle the slide just fine, but I'm not going to let anyone else drive until it gets fixed.

2. I've adjusted the rears but I don't think they're adjusted quite right. I've been told to spin the tires so they make 1.5 revolutions. Well they're making 1.25-1.5 revolutions, both of them. Is there some way to spin only one tire? Open diff by the way. I fear that one might be too tight while the other is too loose, but there's no pulling.

3. When the high idle is active, another problem comes up that's related. The brakes need to be at locking point to stay stopped. This can be overcome by putting the transmission in neutral, but that's only a stopgap measure. If the rears have traction and the fronts are on a slick surface I get pushed forward. I've also noticed that the right rear will often spin freely with the fronts locked and pickup being held in place. I don't know if the same happens on the left as it's always the one on the slick surface.

4. Brakes feel like they're applied evenly from side to side. I haven't had any issues with pulling to one side.

5. Parking brake has no effect. The pedal goes down several clicks freely until it stops suddenly. Doesn't hold either side. Cable isn't broken and I haven't done any adjusting as I want to get the brakes themselves sorted first.

Suggestions?
Bleed brakes?
Adjust rears?
Check something else?

How to do whatever it is I should do?
I'm pretty confident that the bleeding was done correctly as the pedal isn't squishy.
What about adjusting the brakes? I've lifted the rear, put the transmission in neutral, the turned the stars a decent amount. Turning the wheels like suggested results in the 1.25-1.5 revolutions. Am I missing something?


This isn't my daily driver, so it's not like I'm out there sliding around every day. Just last week we got over a foot of snow overnight and I couldn't even get this thing out of the gutter.
I had to take out my Monte Carlo which handled the snow with no problems, but it did dirty up my freshly washed car.

Thanks,
Garrett

 

First adjust up the rear shoes until you hear/feel the shoes lightly dragging on the drum, ignore the 1.5 revolutions aspect of adjusting them. Keep in mind to tight will over heat, burn up the brakes.

When you have them adjusted you can easily check by trying to pry the star adjuster wheel fore and aft within the drum, do so with the brake spoon/screw driver whatever you're using to turn the star wheel.

If it moves the shoes are not adjusted right, for example if you find the star wheel will drift fore and aft a 1/4"? That will cause excessive pedal travel and poor/late brake action, naturally if it moves even further then that, its worse yet! Should be very little/none fore aft movement of the star wheel when your done adjusting up the shoes.

If its new shoes installed in a turned or worn drum, especially one at/near the wear limit, that condition adds to the issue. New shoes do not match the radius of the inside of the drum anymore. So the middle area of lining is the only part making contact with the drum when the brakes are applied, takes some time to wear the lining down until full contact of lining surface is made with the drum. Braking action will suffer some until then but kept properly adjusted will keep any adverse effects to a minimum.

Don't rely solely on the self adjusters to keep the shoes up there tight at first, or even after the shoes initially brake in. Lift it up now and then, check the shoes, you'll know when if you pay attention to pedal travel. If the pedal travels seems excessive, time to manually adjust up the shoes again.

Might not be your only issue at this point but make sure those shoes are right at the drum to start with, go from there if need be.

 

Thank you, I will start with that tomorrow and readjust the brakes and go from there.

 

Just a little side note. You do have front disks, right? ( my 89 did ).

You have a proportioning valve -- I think near the m/c. That sets the amount of fluid between the fronts and rears. If you continue to have trouble getting the fronts to come in, you might check on that.

Of course you also could general problems in the front.

Good Luck,

hj

 

Yeah, they're disk in the front. I haven't really looked at them yet but I may tear them down eventually. All I've ever worked on was disk brakes so I'm fine with them. This is just the first vehicle that I've owned with disk brakes anywhere.