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dalexis · 12-07-2016, **(Subject: Service brake problems in wet weather )**

Hello, been driving a 2015 freightliner cascadia and yesterday I had problems with the service brakes on the tractor just decide they would stop working. The brake pedal was stiff and extremely hard to push. There was a little bit of braking power present but not much and when I really stomped on the brakes it would pull to the left. The trailer brakes were working just fine through the trailer brake valve on the dash. When i started out that morning everything was working just fine, made my delivery at the lowe's store and headed out. The brakes worked just fine on the way out to the interstate. Traveled around 30 miles without touching the brakes but when I went to get off at my exit that's when I first noticed the brakes were not working properly. During this 30 miles or so it was pouring down rain. By just the way and how it happened i've been thinking this is more along the lines of an electrical or possibly a foot valve problem. Anyone else out there driving an freightliner having these same issues and can point me to the culprit?

BTW: the brakes were checked and they were not out of adjustment and they all appeared to be activating as they should. I have driven for nearly 16 years and have never experienced this sort of problem before. Pretty spooky when you try to apply the brakes and there is nothing there to stop you.

in2trux · 12-07-2016, **(Subject: Service brake problems in wet weather )**

Did you check the actual pressure to the trailer?
The lack of an application air pressure gauge on late model trucks saves a few bucks but does nothing to help the driver. I always thought it was a valuable tool to have a better feel for the working condition of the trailer brakes running down the road.

Can you rule out the trailer?
I ask because I have lost service line pressure on the trailer due to air leak and it was pretty much like driving with no brakes, very unnerving.
Any large leak in the supply line or somewhere on the trailer?

One thing I do is to dry my brakes in wet or freezing weather by light application often so I have a better feel of how quick they will set up. I hate surprises.

I ran a 2015 FL for awhile and hate them for a number of reasons. First being the actual feel of the truck. I equate it to driving a marshmallow but that is probably more because I learned to drive trucks that were more like tanks. Somewhere in between is the happy medium.

There have been problems associated with RSD (reduced stopping distance) brakes from glazing and brake valves not seating. I would check that you can get a full 90+ psi to the trailer.

List of recall items on 2015 Freightliner,
http://www.arfc.org/commercial/freightli...calls.aspx

Johnboy · 12-08-2016, **(Subject: Service brake problems in wet weather )**

Honestly sounds to me like wet brakes it can definitely catch you off guard. I guess my question would be do they work better now that your out of the wet stuff?
When was the last time you drained the air tanks on the tractor?
If you drop and hook alot it's a good idea to try and drain the air tank on the trailer you never know how the air system on the previous tractor was working.
Coming into winter if you find any water in your air tanks on the tractor it would be a good idea to get the air dryer serviced and dose the tanks with alcohol.

Hedley · 12-08-2016, **(Subject: Service brake problems in wet weather )**

inspect your service (blue) line and make sure that it is not kinked between your tractor and trailer or in the trailer tandem slider area, also..make sure that the exhaust port on the relay valves are not clogged, you should be able to hear the valve sneeze as you apply and release your brake pedal.

Rawze · 12-08-2016, **(Subject: Service brake problems in wet weather )**

Everyone so far has had some good advice. I would like to add to it..

A loose wheel bearing and leaky wheel seal will make the brakes fail due to oil getting into the pads. Make sure you don't have a wheel seal leaking.

You could have also run through some oil in the road that does this, and are you sure it was the brake pads not grabbing? or perhaps a slick tire.

Regular comprehensive and thorough Inspections,.. Very important. -- It can even be too much slack in your s-cam bushings, pad thickness, a sticky or water-filled chamber, etc.

When is the last time you drained your air tanks to check them for moisture. -- Got ANY moisture in them,,.. REPLACE THE DESICCANT FILTER on the air dryer!!! -- otherwise you may have even more problems in freezing weather.

scottydogtruck · 12-08-2016, **(Subject: Service brake problems in wet weather )**

Dessicant.......spelling nazi has spoken!!!

Rawze · 12-08-2016, **(Subject: Service brake problems in wet weather )**

(12-08-2016 )scottydogtruck Wrote: Dessicant.......spelling nazi has spoken!!!

LOLZ you need to check your spelling too. in fact a lot of places that sell them get it wrong too...
-- Actually it is Desiccant

https://en.wikipedia.org/wiki/Desiccant

dalexis · 12-08-2016, **(Subject: Service brake problems in wet weather )**

There are other drivers in this fleet having the exact same problems, These are relatively new trucks just over 100k mileage and some less. Lots of great suggestions but none of them seem to be what caused this. No wheel seals leaking, no air obstructions, no water in the air tanks, brake pads are not worn, did not run through any oil on the road, wheel bearings not loose etc. the wet weather should have no effect on braking power, been through tons of rain storms worse than this 1 and never had a brake failure like this with the pedal feeling like a brick. The brakes were simply not applying except for the left front drivers side. It kind of acted like more of a valve problem because one brake was working while the others were not. What in the braking system would allow pressure to be sent to 1 wheel but not to the other wheels?

Rawze · 12-09-2016, **(Subject: Service brake problems in wet weather )**

(12-08-2016 )dalexis Wrote: There are other drivers in this fleet having the exact same problems, These are relatively new trucks just over 100k mileage and some less. Lots of great suggestions but none of them seem to be what caused this. No wheel seals leaking, no air obstructions, no water in the air tanks, brake pads are not worn, did not run through any oil on the road, wheel bearings not loose etc. the wet weather should have no effect on braking power, been through tons of rain storms worse than this 1 and never had a brake failure like this with the pedal feeling like a brick. The brakes were simply not applying except for the left front drivers side. It kind of acted like more of a valve problem because one brake was working while the others were not. What in the braking system would allow pressure to be sent to 1 wheel but not to the other wheels?

abs module problems?, otherwise air goes to both pads at the same rate I thnk. The line is just "t" line supplying them I think all the way to abs modules.