Builds "Rednexus" - 2007 GX470 Build and Fabrication Thread (8 Viewers)

[Rednexus]

Nice! My refrigerant is now starting to need replacement, AC still works but got the climate control warning popup so it's detecting it is starting to get low. Somehow it made it 15 years on the factory refrigerant, at least there is no history it was ever changed and my previous owner was not a DIY'er, they took it to the dealer for everything. I'm going to let my local trusted mechanic shop do the work to make sure there are no leaks and to keep local business IN business.

P.S., why'd you replace the horns with those PIAA ones? What's the sound difference over factory?

Bad news. It's a pinhole in the hardline that I had repaired with AC-specific epoxy in 2021 . It didn't hold vacuum....some more black light investigation found the leak (inside the corrugated tubing that covers the hard line - so it wasn't immediately noticeable). I'm going to have to either re-do the Alum-Bond epoxy repair or attempt to braze it. It's on the big low-pressure line that runs from the condenser all of the way back to the rear AC. So, the hard line is not removable.

PIAA horns are a bit louder than factory, but not drastically so. I'd prefer something with a few more dB honestly.

 

[GrizzlyClint]

PIAA horns are a bit louder than factory, but not drastically so. I'd prefer something with a few more dB honestly.

Solution.

Nathan AirChime K5LA Train Horn

Discover the Nathan AirChime K5LA, the ultimate train horn with a powerful tone and unmatched quality. Experience the real deal, perfect for limited vertical space installations.

hornblasters.com

 

[Super]

Those Nathan AirChimes have gotten expensive!!
I have an antique P series 3 bell set. Mine were cast back in the 50’s. Had to keep those when I sold my Peterbilt 379 back in 2010. Nothing like legit train horns to get someone’s attention

 

[GrizzlyClint]

Those Nathan AirChimes have gotten expensive!!
I have an antique P series 3 bell set. Mine were cast back in the 50’s. Had to keep those when I sold my Peterbilt 379 back in 2010. Nothing like legit train horns to get someone’s attention

I desperately want to install a K5LA in the spot where my spare tire is.

 

[Rednexus]

^So here is the skeleton in the AC closet. In 2021 when I was installing the lift, I cut off the top of the OEM strut with a sawzall due to the bolts being rusty/rounded off. I had no idea there was an AC line behind the strut....until the tip of the sawzall blade pierced it and I lost all of my Freon. This is a single hard line that runs from the AC condenser all the way back to the rear AC. I don't think it's removable without cutting it up. So in 2021 I used some ALUM-BOND epoxy for the repair, which worked just fine until last week when the repair finally failed (note this photo was taken after I had bent up the inner fender for better access).

^With the UV light on. The corrugated plastic sheathing was full of UV dye and PAG oil (not showing here). It's apparent that the Freon/dye had soaked into the epoxy repair.

^About half the epoxy came off with a pick. The rest came off with various Dremel attachments. It's pretty thin at the original pinhole location. I have a nice MAP brazing torch and aluminum brazing rod with flux coming in later this week, and I'll attempt a permanent repair. Haven't done a lot of brazing, so hopefully this holds. If not I'm back to ALUM-BOND or trying to find a mobile TIG welder.

 

[Rednexus]

The rig had also been having intermittent MAF issues this week. They started after I detailed the rig, including washing the engine bay. It was throwing codes for "low MAF voltage" (I think they were P0102) and actually died a couple of times. It also had some intermittent strange behavior on vacation, including a spell in MT/WY where it was low in power and had super-high fuel trims (which I at the time attributed to tank of bad gas).

But, this isn't the first time the rig has had MAF issues. I had to splice on a new connector in 2021 to address ongoing lean codes, and then again in 2023 or so. Both splice jobs were some of my "early" electrical work, using 16-22 ga heat shrink butt splices, which I've since found add a small amount of resistance to the circuit and can cause problems with engine sensors (they do work just fine for wiring up non-sensitive things like lights and accessories, however).

^So, I made a new MAF pigtail. This included a new Amazon MAF connector, with a 6-pin male Deutsch connector on the other end, that goes into another 6-pin female connector that I spliced onto the OEM MAF harness branch of the main engine harness. I've had great luck with Deutsch connectors in other sensor applications as the connection is robust, they have nominal resistance, and they are watertight. And, if I ever have another MAF connector issue, I can just replace the pigtail without having to cut off more of the OEM harness.

^Here is it installed (the female Deutsch connector is on my ARB twin bracket - also note that the rig has a Hewitt Tech SAIS bypass which plugs into the MAF too). I went ahead and built a spare MAF pigtail and threw it in the spare parts stash in the back of the rig. Upon startup, STFTs were way lower, indicating that I indeed had a problem in the MAF wiring before, where the MAF was under-reporting the amount of air getting to the motor. It it continues to have issues I'll try running with the SAIS bypass removed from the MAF wiring.

 

[Super]

Brazing aluminum isn’t too bad. I’ve done it several times on Trane outdoor AC units with much thinner tubing and was nervous the first time. Went smoothly and next time I didn’t even blink. Wire brush and acetone are your friends when prepping.

 

[Rednexus]

Brazing aluminum isn’t too bad. I’ve done it several times on Trane outdoor AC units with much thinner tubing and was nervous the first time. Went smoothly and next time I didn’t even blink. Wire brush and acetone are your friends when prepping.

Thanks! I hit it up pretty good with a Dremel wire brush but will hit it again before brazing. Pretty sure I have a can of acetone sitting around as well.