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Testing operation of PacBrake

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I've been following a thread on IRV2 for the last 3 weeks. https://www.irv2.com/forums/f123/cummins-isc-350-with-low-turbo-boost-only-15-psi-626352.html

The initial complaint was loss of boost.  I was the first one to respond and basically said check CAC and PacBrake.  Long story short after having it the shop and checking everything, replacing exhaust manifold (which probably needed to be done anyway), they finally found that the PacBrake was not operating correctly.  As of now he's looking a +20 hours labor plus parts.  The PacBrake air cylinder cost $185 plus probably an hour to change.    You might say this was a hard lesson learned.

Anyway, I lube my Pacbrake twice a year.  Not hard but after the ordeal above I decided I'd like to add a momentary switch near the PacBrake so that I can actually activate it an watch it work.  I have a power source back there.  Is it as simple as wiring in a momentary switch and wiring it to the red wire, which I assume is (+), on the PacBrake solenoid???

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19 minutes ago, tmw188 said:

What type of lubrication do you use on that Jim don’t they make a special pack brake lube?  I’d like to see a photo of your switch set up there?

Yup I use the PacBrake high temp oil, I'm sure there are alternatives but I bought a small bottle ~10 years ago and have hardly used any of it.  https://pacbrake.com/superlube-exhaust-brake-lubricant.html

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To operate the Pac Brake it just needs 12positive and 12v negative- oh and air in the air tank.

in testing mine, I just brought a separate battery to the engine area and used that to operate it while oiling it up with the pac brake oil.

Also, does anyone know where the relay is that operates the pac brake?

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I wired in a momentary toggle switch for the PRXB PacBrake on my previous Windsor many years ago when Fred White (RIP) was still alive. It is located on the plate of solenoids that is accessible under the floor cover in front of the closet. You just have to determine which solenoid is for the PacBrake and wire in a 12 VDC positive to it. No ground needed. Just a hot signal to activate the unit.

The proper wire should be in the electrical schematics for the 02 Windsor. I will check my 02 Windsor folder to refresh my memory and re-post.

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Bob, Michael, and Richard


My air solenoid is mounted under the starting/grid heater solenoids.  Can't see it but I traced the air line.  Just a two wire solenoid I'll just have to figure which wire it (+).  The wires just go into a mass of other wires.  

2 hours ago, tmw188 said:

I think I use some anti seize grease on mine one time. Ever heard of using that?

I have antiseize grease but I don't think it's high temp.   Working in the underground mines it was used on any bolts on equipment that might have to be taken apart in the future, otherwise everything just pretty much rusted together. 

There are other high temp lubes but there wasn't much cost difference so I bought the one recommended by PacBrake. 

When I lube the PacBrake I take the airline loose and put a little down the hose so that tie will lubricate the inside of the of the cylinder.  The link that I provided ultimately resulted in them finding the air cylinder had failed. 

Edited by jacwjames
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Its funny however earlier this year after replacing the exhaust manifold i swear that my pac brake has become less effective if working at all, i know its working cause i lubed an tested it. I believe the reason is with the leaking manifold everytime i used to turn it on it would whistle, so in my feeble mind i acquainted operation with the noise, so now there is no more noise so as the gray matter is concerned no noise = not working🤪

However i do know it is, due to driving next to a barrier i hear it when braking. 


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