Freightliner ‘pass-thru’ manifold

[snailexpress]

(09-12-2021 )SquareOne Wrote:  Thought I’d let any Freightliner guys know about this info I discovered yesterday. Apparently in many Freightliner trucks (I have a Cascadia) there is a ‘pass-thru’ air line component which houses a large amount of air lines coming from outside the truck, to inside. This is located at the firewall right above where your driver foot would be , or if you’re looking from the outside....yeaaaa all those pretty colored airlines....well that’s the component I’m talking about.

This seems to be a common point of failure and also seems like a real Pain in the a$$ to change. I believe that part is a couple hundred bucks as well. Even if only one of the fittings begin to leak, it seems a replacing the entire assembly is the only option.

Since I can’t stand pissing away time/money on changing otherwise good parts I decided what did I have to lose by trying to repair the leaking fitting. Long story short, if you carefully remove the quick connect coupler from the leaking fitting, it will reveal an o-ring you now have access to. If you carefully replace that o-ring, your leak issue will be corrected for literally pennies as well as very little time/effort when compared to replacing the entire assembly.

Maybe many of you know this info, but for those who don’t, give me a shout if you need any other info.

We do it on Volvo truck every like three months interval. When tube is out check the cut end is perpendicular and surface is smooth, no reinforcement thread .
Just FYI pass thru manifold has some internal connections between ports. Not every port can be drilled thru. As an example big supply line inside the manifold connected to pressure sensor port. Same for stop light switch.