Common air leak on the Freightliner Cascadia, the pass through manifold or air manifold located in the driver side firewall just behind the foot brake valve. You can try to remove the air line and cut tip off and then reinsert the air line and see if that helps. But the problem is usually in the fitting itself which is NOT serviceable.
TOOLS needed: torx bit set, ratchet, extension, 1 and 1/16 deep socket and maybe flat screwdriver.
Takes about 1-2 hours to remove and install depending on your experience.
Super easy to do yourself.
24 Replies to “Common air leak on a Freightliner Cascadia, pass through manifold or air manifold”
If it's a plastic air fitting on a Cascadia it will need to be replaced… lol
I just replaced that on my truck good video
Great job on the video👍🏻
Why not just replace the sensor?
How many hours will a dealer charge for this? Great video.
Wow! Wow! The best directional, Instructional and informative Video ever. I have a leak in the passthrough in my 2012, and C.D.E just saved me time and money! Thank you / Asante Sana!
My 2016 cascades losing secondary air while driving, it drop down to 90 then 125 and keeps doing it every couple of minutes, when I stop to check for leak I can’t hear anything, it only happens when pulling heavy load , bobtail or empty is fine , any idea what should I check for thanks
About to replace mine tomorrow after I stop
Would replacing this would fix the "transmission low air" problem?
Hey bro I have a 2009 cascadia and I have a leak from the middle sensor do I have to replace the whole part or just that one sensor
Just make sure you clip air lines a quarter 8n and be sure and push them all the way in. I didn't initially and paid the price. Also put new switches in at this time as well.
A whole lot of talking just demonstrate how to do its do its
Hey man I’m not even sure if this is relevant but I keep losing a lot of air from my valve brakes. I’m not sure why but they were leaking air when I stopped to fill my tank and now the alarm just keeps sounding but the gauges are at 100. Hopefully you see this in time any suggestions?
The o-rings inside the manifold are replaceable. Spent $0.90 replacing three cracked o-rings. New manifold is around $180 at freightliner so I saved a lot fixing my old one. Look into this before replacing the whole manifold!!
Thank you buddy you gave the confidents to do it myself and you spoke english..God 🙌
Would the location be the same on a 2021 cascadia ?
Gracias your knowledge really help me with my air leak under the cab. Many blessings.
I only have the yellow air hose leaks on the engine side. Do I need to replace the manifold or the ending fit? Where is your shop? Thanks!
This video is giving me nightmares. Had to do this 8 months ago, it was not fun.
my friend you are throwing your money in the trash just replace the o-rings
how you figured out that was bad
My shit is leaking right where the sensor is. Can I just replace the sensor?
thanks for the insight I am working on mine now.
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