Sticking PacBrake

[FDziurda]

Anyone else having problems with their PacBrakes sticking in the engaged position? Mine works fine at idle or when EGTs are reasonably cool, but tends to want to stick when the EGTs are 600+ deg F. It eventually releases but sometimes takes 15-20 seconds!



Have tested the vacuum solenoid and it is working properly. Also have 22" of vacuum, so that shouldn't be a problem.



If anyone out there has had a similar problem and came up with a solution, I am sure open to suggestions



Am just about ready to pull it off the truck and see if I can find something wrong.



Thanks all,



Frank

 

[Blu-meanie]

Did you try lubing the linkage with a high heat lube?

 

[Sticks]

I have read that if the E-brake is not used frequently enough, they can build up carbon deposits on the butterfly and cause problems. Maybe unbolt and pull it back a little to check inside? Just a thought.

Sticks

 

[FDziurda]

Thanks

Thanks Guys.



My next chore was to remove it from the truck and check the butterfly, to see if there was any carbon buildup.



I have lubed it with the hi-temp Superlube that is recommended and that didn't really make any difference. When it is cool, and I can get my hand in there, I can easily move the linkage back-and-forth, as long as I remove the vacuum lines.



Frank

 

[DCMille290]

After 2 years, I started having the same problem with sticking.

Here is the test from Pac Brake: Remove the incoming & outgoing vacuum lines from the solenoid. Plug the ends of the hoses so no air can push by, then reach down, cool brake preferred, and try and move the butterfly assy. If it moves easily, in or out, then one of seals inside needs to be replaced. Call Pac Brake and they will send a new cylinder and an address to return the old one.

Easy job, remove entire Pac Brake, unscrew fittings on old cylinder and re-install new cylinder and stick the Pac Brake back on truck. Did mine in about 30 mins. No more troubles.



Good luck,

DC Miller

Marbleman

 

[drees1]

Mine sticks when it is below freezing. I'm assuming the vacuum solenoid is freezing or the bronze vent plug is freezing with water vapor. Above freezing, never a problem. Not sure if there is a fix for this. Anyone???

 

[R.ebel]

Had the same problem with sticking Pac Brake. The fix is a new vacuum cylinder. Works great now.

 

[FDziurda]

Contacted PacBrake

Thanks DCMille290!



I performed the test you detailed and there is virtually no back pressure, so it appears the seals are gone inside the cylinder.



I have emailed PacBrake and am awaiting an answer. Will post when I hear from them.



Thanks everyone for the help,



Frank Dz

 

[jelag]

The test for the cylinder is correct... ... Besides the cylinder wearing out we have found many of the exhaust brakes that gum up from lack of use..... we own 6 trucks with them and each truck except 2 have over 250K with the orgional pac brake but we never turn them off..... If you have a worn out cylinder look at the condition of the filter on the solenoid... ... if it shows any damage than replace it... . remember the air has to pass through that filter each time you shut off the exhaust brake... ... any dirt there will damage the solenoid and the cylinder... .



There is a new lube made by PacBrake C18037... . we put a drop on the shaft each time we install one... . both on the inside and the outside..... We sell the stuff for under $6. 00 so check with your local PacBrake Dist for it... ...



If you any specific questions, you can contact PacBrake directly... from their web sight... or me with a pm... .



Have a great day...



Jim