Brakes locking/soft during/after wet weather, again and again

[Pete99]

2002 Edge, 4.0 Automatic 4WD, 120,000 mi

Last year I started having two problems with my truck: the speedometer needle flickered at idle, and the brakes locked up or were very soft after wet weather.

My mechanic replaced all the speed control sensors and some other brake components, and everything was fine. Briefly.

I brought it back in a couple of months later after a very close call with a soft brake pedal. Again, it came back fine. Briefly.

The third time, I was told that the rear differential was on its last legs, and friction was causing heat to transfer down the axles, cooking the sensors and other wheel-area components.

Too much time and money later (so long that it ruined my relationship with them permanently), I got the truck back, and within a few weeks it was doing the same thing again.

What were these guys missing? tYying to do a little research before going to the next mechanic.

 

[55trucker]

If you suspect that the rear axle IS getting hot pick yourself up an infrared thermostat gun and monitor the rear brake assemblies running temps.

I can't see this happening on short drives, heat needs time to thermally conduct, but perhaps on long trips if the shop was correct, but the fact that you have the truck once again and the problem persists suggests they were wrong.

http://g01.a.alicdn.com/kf/HTB1ZO.q...ter-Laser-Temperature-Gun-Meter-Sensor-50.jpg

 

[gw33gp]

I don't like suggesting more things to try because it may send you down the wrong road. However, one thing comes to mind that may be contributing to your problem. A soft pedal usually is an indicator of air in the brake hydraulics. I am sure they have been bled but the ABS system has to be bled in a special way to may sure air is 100% out of everything. You may need to take it to a Ford dealer to have the brakes hydraulics totally flushed properly.

 

[Ranger4x4.0]

Every ranger I've ever had done this while wet. I just deal with it lol

Sent from my SAMSUNG-SM-G890A using Tapatalk

 

[Jimmyrig]

I agree with gw33, there are a lot of possibilities, the differential would be towards the bottom of my list, especially if you aren't experiencing any other symptoms like lots of noise from the rear end. I've found that brake problems are usually brake problems. Brakes work by turning your motion into heat. Heat does bad things to car parts, too much will kill your speed sensors, but it will also boil your brake fluid causing gas bubbles creating a soft pedal, break down the seals in your wheel cylinders, causing soft pedal, (because they will leak, probably not your problem) and it can also cook the axle bearing seals. If it was my truck I would drive it ten miles or so on the highway, slowly stop then see if I could hold my hand on the drums without getting burned. If not the brakes are dragging causing your issue. A simple adjustment and fluid flush would fix it, although new shoes would be a good idea. That's assuming it's the rear brakes. Calipers can stick creating the same grabby then soft pedal situation. Or a master cylinder, some brakes are grabby when they're cold, but a master cylinder just starting to go can cause soft pedal that can go away if you pump or bleed the brakes, only to come back again. The unfortunate truth about mechanics, especially younger ones, is that today 90% or better of the diagnosis is done for them. Plug in a scanner and it tells you what's wrong. Some of them are close to clueless without this especially if they didn't know much before school. I'm inclined to blame this for the theory that your differential is the problem. It is possible, but unlikely. I would be willing to bet the issue is inside the drum if it's the rears, or in the caliper or wheel bearing department if it's the front. Those are the obvious theories, and it's where I would start if it was my truck but it could be any one of a hundred things.

The speedo thing has me curious, because the sender for that should be on the transfer case unless I'm mistaken, the sensors by the brakes should just be for the ABS, not the speedometer

 

[heavy breather]

Its interesting that jimmyrig brings up a scanner. I was thinking you should find a reputable shop that has a bidirectional scanner and can look at and communicate with the ABS pump. A good scanner in the right hands is a good diagnostic tool, in the wrong hands, it can make a parts changer lots of money. Codes can be thrown for multiple reasons. A good Tech will look at the code and think to him/her self, why would that code be popping up? A parts changer will just replace the sensor responsible for the code.

If your break issues are dependent on wet weather, I would say the ABS module/pump likely has an issue. It could be any thing from a short/bad pigtail, to a bad pump or module.

The dealer is not the first place I would go, ask around a bit. Talk to the guys at the parts stores, not just the new kid at the Orielly's, but find a good parts house with a guy who has been around for a while, he likely knows a shop.

 

[adsm08]

Are the little rubber plugs for accessing the adjuster screws in place? My wife had an S-10 that did EXACTLY what you are describing. It had done it from new. I was the first person to ever work on the rear brakes as far as replacing stuff, and had to punch out the spot-welded tabs over those holes to adjust stuff. When I was done I put the rubber plugs from the hardware kit in and viola, the problem went away, didn't do it again for the rest of the time we owned it. I figure it must have been water getting into the drums.