Service brake problems in wet weather

[snailexpress]

(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?

One of my friends has same complains for the brake system.

[simon999]

Freightliner has service bulletin for excessive moisture in air system. I suggest update your dryer parts, costs about $500 in parts.

  oil in air system-1.pdf (Size: 232.01 KB / Downloads: 471)
Also like was mentioned in previous posts it is important to replace your dryer cartridge(I replace it before every winter). If your dryer doesnt work properly you get moisture in the brake valves and that causes freezing brakes in cold weather.

[trucklogger2]

I would include the abs relay valves on your tractor and treadle valve(usually under cab) for proper function. And recall as others have said.

[dalexis]

Might add there were no faults when this happened, not sure if that would rule out electrical type problems.

[scottydogtruck]

(12-08-2016 )Rawze Wrote:  

(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

Ok...I lose...lol!!

[dalexis]

Hey guys sorry to bring this post back but still having problems with the brakes. It rained really hard today for the first time in a while and the brake problem reared its head again. Brake pedal felt like a brick and had to use the trailer brake valve to slow truck.

I found a service bulletin 42-69 excessive moisture in the air system but the truck is not having any of the symptoms it describes. This "ONLY" happens when it rains really hard and there is no error code.

Found a post on another forum about the rain trough under the windshield leaking down onto the compressor. Kind of leaning in that direction. Was thinking of maybe taking a couple gallons of water and try to replicate the heavy rain to see if it is in fact leaking onto the compressor. This is on a 2016 freightliner cascadia.

Thoughts?

[snailexpress]

(10-05-2017 )dalexis Wrote:  Hey guys sorry to bring this post back but still having problems with the brakes. It rained really hard today for the first time in a while and the brake problem reared its head again. Brake pedal felt like a brick and had to use the trailer brake valve to slow truck.

I found a service bulletin 42-69 excessive moisture in the air system but the truck is not having any of the symptoms it describes. This "ONLY" happens when it rains really hard and there is no error code.

Found a post on another forum about the rain trough under the windshield leaking down onto the compressor. Kind of leaning in that direction. Was thinking of maybe taking a couple gallons of water and try to replicate the heavy rain to see if it is in fact leaking onto the compressor. This is on a 2016 freightliner cascadia.

Thoughts?

Next time when you got rainy weather and bad brake check with someone help is it braking system or just wet shoes and drums. Do you have brake apply pressure gauge? What is the pressure?

[Rawze]

(10-05-2017 )dalexis Wrote:  Hey guys sorry to bring this post back but still having problems with the brakes. It rained really hard today for the first time in a while and the brake problem reared its head again. Brake pedal felt like a brick and had to use the trailer brake valve to slow truck.

I found a service bulletin 42-69 excessive moisture in the air system but the truck is not having any of the symptoms it describes. This "ONLY" happens when it rains really hard and there is no error code.

Found a post on another forum about the rain trough under the windshield leaking down onto the compressor. Kind of leaning in that direction. Was thinking of maybe taking a couple gallons of water and try to replicate the heavy rain to see if it is in fact leaking onto the compressor. This is on a 2016 freightliner cascadia.

Thoughts?

If your getting water in the air system, then the tanks will be full of it. Open the bleed valves and see if the tanks are full of water. If so, then your decadent filter/ air dryer filter element is toast along with any other problems you might be having.

If could also be polished brake pads form someone overheating them badly too. Water gets on the shoes and they stop having any friction on them if they are glazed over. - I would replace the all the pads while your at it if they have any signs of this.

[Sergiu]

Maybe some moisture got inside your ABS relay valves' electrical connections they are very sensitive, a new valve solenoid will show only 4-7 Ohms of resistance, everything else is out of spec and may influence your braking.
P.S. not related to your problem but could help somebody:
On my 2012 cascadia -- two abs valves under the fifth wheel has been leaking air only when tractor brakes were released, I thought it could be worn o-rings, seized valves/electronic actuators or bad programming. I decided to go for 1 year warranty on a new part (two abs valves and relay valve), freightliner parts guy told they change those all the time, seems something usual for 2012 cascadia, didn't have this issue once on my 2010 peterbilt though. Today I replaced that part and still was losing air until I found that two of my brake chambers had an internal leak. The air is leaking through the center near pushing rod from the spring brake side, and going back up the service line and out the exhaust of the relay valve. I took off the service line from each maxi one by one to find the culprit. Changed defective brake chambers and everything is working properly. BTW my truck was pulling to the right all the time, three alignments didn't solve the issue, also brake shoes on the passenger side was thinner then those on driver's side. The reason was internal leaking defective brake chambers.