Does anyone else have a problem with their PacBrake not engaging when it's cold outside? Ever since the weather started turning colder, my PacBrake works one time, then won't engage until the outside temp. gets around 50. When I get up in the morning, I go out and start the truck with the brake on to let it warm up. I go in and have breakfast (a glass of milk) and brush my teeth. When I leave about 10 minutes later, the truck is warm and heat is blowing. Once the brake releases, it won't engage again in my hour commute. This isn't a huge problem, but when your used to slowing down when you let off the pedal, you kinda get that "oh crap" feeling when you let off and don't slow down. I'd had a similar problem a couple of years ago, but it stuck on (engaged). Now, given the choice, I'd rather it stick off than on, but I'd really rather it not stick at all. PacBrake sent me another solenoid when it was sticking on, but it was like pulling teeth to get it from them. Has anyone else had this problem? What did you do to fix it? Thanks for your help.

David

 

Check your pivot pin and lubricate, instructions should be with your instal paperwork. Good Luck

 

Check your vac hoses. They might be hard and leak when cold

 

I have been running mine since 1999 and have had no problems to date. You might be getting some moisture, like condensate, in the vac line at the solenoid and the cold freezing it up.

 

The way to tell if its the solenoid is when it wont work, stop open the hood and push the button on the end of the solenoid. If you dont know what I mean, its on the end of the solenoid and it should be black. It also doesnt look like a button but you can push it with a small screw driver or something. What it does is push the plunger back to the OFF position but in your case you are feeling for it to be in the ON position, given you still have the engine running and the Pac still on while you try this. The switch is really there in case the plunger sticks and doesnt let the Pac turn off. At least you'll know that much. If not then try pulling of the hoses and sucking on them with you mouth to see if you are loosing vacuum. If you are then you have to determine if its the hose or the canister. I had trouble with mine sticking twice and Pac couldnt have been nicer about helping me and sending me parts. Funny cause there really isnt much to them mechanicaly but when they give you fits it can be a pain to locate the problem.

 

I had problems with mine sticking on and not engaging. I took the soleniod apart and cleaned it put it back together and it worked. I'm betting you have moisture in the lines and it's freezing.

 

Although I tend to run in extremes of temperature, I am currently on my 3rd vacuum canister from pacbrake. They have been very good to me as far as warranty goes.

I do not use the pacbrake for warming up, only for its original intended purpose, of adding whoa power. the canister does not react well to the cold. Each time I have had trouble, I go through all the troubleshooting steps, including the button on top of the solenoid, checking for vacuum leaks, and so on. I keep the unit lubricated with the proper PacBrake High Temp Silicone Lube. It just so happens that they work for about a year, then start to bind up in the cold weather.

I have discussed this at length with representatives from the PacBrake company, as I install a fair number of these units, and it would be good to find a cold weather solution.

As soon as the temps dip to about -10 to -15c here, the brake canister becomes a paperweight, although mine sticks in the "on" position, and won't shut off until I open the hood, and physically attact the pivot with a dead blow hammer. a couple sharp raps and it frees up, but as soon as it engages again, same problem.

Almost like there is a taper that is catching the piston inside the cylinder???

Be neat to find out.

 

I went through the same with a buddy's Pac brake cylinder. On the third try Pac provided a new improved cylinder, seems to be working great, been almost a year now.
Pac is a great company to work with, no charge on anything even though the brake was way out of warranty.

 

Thanks for all your imput. I lubed all the pivot points and the ram on the vacuum cylinder. I don't think that's where my problem was, because everything moved freely when I took the vacuum lines off. I took the vacuum solenoid apart and cleaned everything with contact cleaner. It didn't look dirty, but I sprayed everything out pretty good anyway. The first time I had cleaned it, it looked like it was full of graphite or something. This time it looked clean, so I put everything back together. It's been working like a champ ever since. Thanks for you help, guys.

David