Pac Brake does not work until warm in under 28 degree cold weather?

[KaiHartman]

Have started using my Pacbrake (installed about two months ago) more and more now that it is getting colder here in Indiana. However, once the temps dropped into the 20's, my Pacbrake will NOT come on until after the engine has been running awhile!



I thought it was surely something faulty in my wiring, so I've messed with solenoids and the switch and stuff. No luck. I began thinking I had a leak, but compressor comes up and holds air fine. It seems like something in the truck might be telling it to not activate. Is this a part of some special cold start cycle that I"m not aware of?



Don't get me wrong... it could still be something in my wiring... but after the truck hits, say 150 degrees coolant temp, the brake automatically comes on and works perfect from there on out!



I am wondering if the components in my switch are affected by the cold weather enough to prevent them from working until the interior temp comes up... . I will experiment with this by eliminating the switch tomorrow. IF this doesn't pan out and I can't figure out the problem, I guess I'll have to disconnect it from the ECM harnesses up front and run it off my switch alone...



Has anyone else had this issue? As always, THANKS to everyone who has some input!

 

[wcjp]

We don't have consistent cold temps here in the Pacific Northwest. When the temps do dip the Pacbrake works no problem. My first guess for your problem is a sticking relay. Second, water in the system. Compressor's are great at creating condensation. Maybe install a drain on the airtank.

 

[CumminsBu]

Water in the air lines???

 

[TBartlett1]

Mines doing the same, I believe the moisture in the air has frozen in the compressor.

 

[KaiHartman]

I checked my truck this afternoon (25 degrees). Compressor filled up the tank to full pressure just as it should, right away. Pacbrake did not start working until coolant temp was 140 degrees.



I'll try to check the tank for water ASAP--THANKS for the suggestion!



I did eliminate the switch today with a jumper wire and the Pacbrake still would not function when cold. However, came on and worked perfect once the trucked warmed up as I mentioned above.



Do you think ice is in the lines near the actual exhaust brake? That's the only thing I can think of... . because my compressor and tank are mounted in bed in front of my toolbox. Of course, the exhaust crossover pipe runs fairly close to it, but it has never seemed to get too hot up above where I have the compressor mounted.



Could also be a relay... . I hope I get it tracked down soon. Hopefully something I messed up or overlooked when it was installed. It seems completely pointless for me to have the capability to use an exhaust brake for warmup when it won't come on until the truck is warmer!! Thanks again for the input!

 

[wcjp]

Water in the air lines???

Compressed air will consistently leave water behind. I work with low pressure dryed air at work. To remove most of the water, we move low pressure air through an AC unit to cool the air. When cool the water is easily removed. The saturated air is then pushed through some canisters filled with a media that absorbs water.



While I'm not sure if it'll work, one could hook up the Pacbrake to a shop compressor at say 60psi. Disconnect the air line to the Ebrake at the Turbo. Activate the brake. Might help to do this after engine has warmed abit to avoid pressurizing ice in the lines. Also, install a drain at the tank.