Right rear brake locking up

BigRedWeather

Full Access Member
Joined
Mar 2, 2009
Posts
162
Reaction score
0
Location
Lexington, KY
My back right brake will sometimes lock up when I brake at under 20 MPH going around a curve. Troubleshooting said to replace the RABS II valve which I did. I took it to a good brake shop and they helped it, but now 4 months later I am having the same problems even worse than before.

Is there a set of instructions that will guide you in adjusting the brakes on this truck? With the rear ABS there is quite a bit going on that in the entire brake system.


Thanks,

BigRedWeather
 

tjl

Diesel Nut
Joined
Feb 1, 2008
Posts
174
Reaction score
0
Location
Nashport, Oh
I had the same problem. My emergency brake cable was stuck. If you pull on the cable where it comes through the floor under the truck it should release it. If you use the emergency brake it's not releasing all the way.
 

Goofyexponent

Mentally Unstable..
Joined
Jan 7, 2009
Posts
4,567
Reaction score
4
Location
Halifax / Nova Scotia
I have the same problem. I know for a fact that it's not the E brake sticking as my cables eeized and I had a hell of a job releasing them...so I didn't not apply them since then. I was told that the brake is out of adjustment. I am going to bend a screwdriver to adjust them when the weather gives in a little and warms up and let you know if that solves the problem. The wheel that is sticking is the back passenger side tire...it will drag at low speeds and release when I release the pedal.

I had all the brakes apart and checked everything a mere month or two ago and everything worked fine up until about 3 days ago. I took EVERYTHING apart, lubed it up and put it back together. I made sure that it was all free moving and there was no binding when I put it all back together. I know nothing is stuck.
 

BigRigTech

Diesel junky
Joined
Feb 10, 2007
Posts
3,288
Reaction score
1
Location
Nova Scotia, Canada
My bet is that it's out of adjustment and the e-brake lever inside the drum is sticking....I just re-did the brakes on my 91 and everything was stuck back there....All good now.
 

BigRedWeather

Full Access Member
Joined
Mar 2, 2009
Posts
162
Reaction score
0
Location
Lexington, KY
I'll have to check on the E brake to see if it is releasing or not. However, that doesn't explain this: On a curve under 20 MPH sometimes I press the brake lightly and the right pass brake locks up for 30 - 40 feet and then releases when I let off the brake. It appears that 80% of the braking power is going to that one rear pass brake. Seems this could be caused by a bad Diff Sensor (described below) telling the ABS system that the rear axel is still turning, (when it isn't) so it sends it more pressurized brake fluid. That doesn't explain why the rear pass brake would be locked up and the rear driver brake would not- but that could be because of some other malfunction.

Sometimes it doesn't lock up when going around a curve.

When I drive any trip over 1/2 mile my E brake and ABS light come on at the same time and stay on until the key is turned off. This means the RABS valve isn't engaged and I have regular brakes on the rear, no ABS brakes on the rear.

The RABS brakes have a sensor (I'll call it the Diff Sensor) on the top of the rear differential that looks at a toothed ring to determine if the rear axle is turning. From my diagnosis I am thinking this could be bad. I have the shop manual for my truck but to go through all the diagnostics test would take many hours, and require several tools I don't have access too.

If I go to a professional the only thing I know for sure is that they will charge me another $200 - $300. I also know for sure that a few months later my brakes will be as bad as when I took it in. I am certain, someone knows how to fix them for good. Finding that someone is the hard part.


BigRedWeather
 

Double-S-Diesel

parts seller
Joined
Mar 8, 2005
Posts
2,520
Reaction score
76
Location
derry pa
there is no difference in pressure from side to side on the rear brakes rabs valve will not do this.
usually if the speed/abs sensor is bad the spedo will usually jump.
Im still betting on the cable, I go though one a year.
 

Double-S-Diesel

parts seller
Joined
Mar 8, 2005
Posts
2,520
Reaction score
76
Location
derry pa
there is no difference in pressure from side to side on the rear brakes rabs valve will not do this.
usually if the speed/abs sensor is bad the spedo will usually jump.
Im still betting on the cable, I go though one a year.
 

BigRedWeather

Full Access Member
Joined
Mar 2, 2009
Posts
162
Reaction score
0
Location
Lexington, KY
usually if the speed/abs sensor is bad the spedo will usually jump.

I'm definitely checking out the cable. Are you saying the speedometer will jump if the speed/abs sensor on the rear differential is bad? Is the speedometer driven by that sensor? That would tell real ground speed (if the wheels were on the ground)

Thanks,


BigRedWeather
 

Double-S-Diesel

parts seller
Joined
Mar 8, 2005
Posts
2,520
Reaction score
76
Location
derry pa
yep the spedo and the abs is run by that sensor. if ya replace it stick with ford aftermarket ones sometimes dont work
 

94f450sd

Supporting Member
Supporting Member
Joined
Oct 12, 2005
Posts
6,617
Reaction score
55
Location
somewhere,ma
check the adjustment on the drivers wheel.fords are notorious for the rear brakes backing themselves off,hence the reason i will never go back to an f350 for a towtruck.how often do you drive it?if they sit for a day or 2 or even overnight if its raining the drums will get surface rust on them and cause the same problem you have.
 

7.3n/anut

Full Access Member
Joined
Mar 30, 2009
Posts
108
Reaction score
0
Location
VA
sounds to me like bad adjuster hardware. Mine had the same problem. actually i washed it at a carwash and it was freezing outside and when i went to pull out i got stuck on ice! had to lock it in 4wd and have at it. ANY way i would loosen that brake up and itd be fine then it start again. sound like adjuster hardware to me.
 

BigRedWeather

Full Access Member
Joined
Mar 2, 2009
Posts
162
Reaction score
0
Location
Lexington, KY
I've done a pretty poor job on this post by not telling the whole story at the beginning... My brake pedal is real soft for about 3" then grabs about 1.5" off the floor. It used to be real hard after I pushed it down 1".

I'm gonna say if my speedometer works smoothly, as it does, I will assume the sensor in the differential is working properly.
 

Forum statistics

Threads
91,198
Posts
1,128,136
Members
24,024
Latest member
Bugoo

Members online

Top