Guidance with CO2 Leak Testing

[Tim]

tough to use soap and water on an evap drain tube...

A Florida buddy of mine got one from HF (do not know which one) and believe it or not it has served him well.
I use a TIF (15 yrs old) and I wouldn't want to be without it

Whatever actually works.

[Cusser]

I used soapy water to identify a leak in the center of my 1988 Mazda B2200 evaporator about 2000. I picked up a replacement (in-stock at AMA/Tim's in West Phoenix) and that's still in my truck operating to this day.

My 9-year old daughter helped with the install.

[Tim]

I used soapy water to identify a leak in the center of my 1988 Mazda B2200 evaporator about 2000. I picked up a replacement (in-stock at AMA/Tim's in West Phoenix) and that's still in my truck operating to this day.

My 9-year old daughter helped with the install.

Cusser, many shop repairs started with an acid bath of the core and pressure test while doing it.

[tbirdtbird]

Cusser I would love to know exactly how you did that, since you can't really get at the evap unless you remove it.
Got any other kids you can send over to help with AC work here? LOL Dave

[Cusser]

Cusser I would love to know exactly how you did that, since you can't really get at the evap unless you remove it.

Well, I didn't have a digital camera back then (2000) so no pictures. 1988 Mazda B2200. Evaporator case is on passenger side, under the dash. There are maybe about 8 little clips that hold the bottom of the evaporator case on, and 2 clamp/banding type clips that prevent air loss from each end of the evaporator plumbing.

I was experiencing low air flow out the vents (any vents), and the fan was blowing fine in all 4 speeds, so I took off the evap case bottom to look for obstructions like leaves. I found a bunch of tar-like gunk covering the evap fins. I tried dishwash detergent, would not dissolve the gunk, finally put a catch-bowl underneath and used aerosol brake cleaner and a nylon parts brush to clean off the gunk, and then buttoned up the bottom of the evap case. My air flow was restored, I was happy - for about 10 days.

After 10 days my vent temperatures rose, it dawned on me that the gunk was likely from refrigeration oil mixed with dust. I again removed the evaporator case bottom, got the bubble solution out and found a leak in the center of the evap itself.

This was before I had computer, so I called local Mazda dealer and found that a new evaporator was about $250 and special order, so I'd have to make one trip to pay/order it, then come back in a week to pick it up. So I called Tim at AMA and they had the evaporator in stock at like half the Mazda price. Well, Phoenix is #%^&&$#@%^&&%#%^&&%$ hot in summer, and I needed AC, so I went and picked up the evaporator, and my daughter helped me line it up and install it the next day. I do remember removing the entire evaporator case for that, took us an entire Saturday morning.

That vehicle is still R-12, running a Sanden SD-708 Model 7225 compressor bought new through Tim at AMA in 2014.

[tbirdtbird]

Great job!

[Alan B]

Thanks to all for your responses.

A tech friend recommended Murphy's Oil soap. What do you guys think?

The lowest cost Tek-Mate is 180. Tuff to justify as I might not use it again. Harbor Freight has one for $80 but I'm concerned it may not have the necessary sensitivity for a small leak. Any others with experience with it?

[tbirdtbird]

I am not sure the choice of soap really matters.
Your call whether sniffer or soap.
Be aware that fixing any AC properly is not cheap, ya gotta have the tools.

I looked at the HF one which is re-branded from Elitech. Elitech states that there must be 50 psi pressure in the system. Which could simply be you puffed in 20 psi of 134, then dry compressed air up to 50 or prolly even higher, I would go to 100.

IIRC you had a rather substantial leak.....

Can you borrow your tech friend's sniffer?

And there are other choices of sniffers priced between HF and the 180.00 one

[Cusser]

I have an electronic sniffer from Harbor Freight, cost me like $5 half a dozen years ago.

As for soap bubbles, I've used dishwash liquid mixed with a decent amount of water for finding holes in tires; one can add additional glycerine, what I did back when I worked for the soap company and there was tons of glycerine. For automotive AC leak finding, I've used a big bottle of kids' bubbles from Dollar Tree; it cost - wait for it - $1 !!!

[bohica2xo]

These were more fun