Air System Building too much Pressure

[rtjohnson1982]

Hey everyone, I'm having a sudden issue with the air system on my 2007 International 9200i. It suddenly is building air pressure well past 120psi in both tanks. I replaced the air governor, blew out all the lines including the line running from the secondary tank into the air dryer. Took air dryer apart and cleaned it as best as I could and put a new dryer filter on. Cranked it up and still building past 120psi. I'm at a loss from here and any help would be greatly appreciated! Thank you.

[Rawze]

Air compressor head unloader valve may be whats getting stuck.

The old procedure used to be ...
Take the intake and outlet lines off the air compressor and spray liberal amounts of WD-40 into the inlet while engine is running and flush out any carbon buildup that might have gotten into it.

[Nilao]

It could be the setting of the governor.. mine builds to 135 then purges. Cut in pressure is 115.

[tree98]

Could be your air dryer

[rtjohnson1982]

Changed governor today along with new air dryer filter, gonna take a look at the air compressor unloader valve in the am. Thanks guys, I'll post an update

[rtjohnson1982]

Hey Rawze, wanted also mention that it doesn’t start building excessive air pressure above 120psi until the knobs are pushed in. It will stay at around 120psi with the parking brake engaged.

[Chamberpains]

You never mentioned at what pressure it finally cuts out at.

[rtjohnson1982]

Sorry, it’s building all the way out to 150psi when it does it. Going to try the cleaning trick with WD-40 that Rawze mentioned and I’ll get back. Thanks guys!

[rtjohnson1982]

Hey Rawze, I tried cleaning the air unloaded valve but didn’t help and I wanted to see if you could offer any advice on how to change the valve out? As in where it’s located, difficulty, etc. thank you sir!