Automotive Air Conditioning Information Forum

(reposted to correct forum)

I know that it’s a bad idea to use R134a that includes sealant and dye for finding and fixing leaks even though these are sold everywhere.

But what about a product like FJC 4921 that just has a little R134A and dye and no sealant?

Dye charge cans have been around a long time. Not a problem. As long as they have only Dye

Generally they are smaller, and contain a couple of ounces of refrigerant to move the dye, along with some oil that suspends the dye

The product you mentioned has 2 ounces of refrigerant, and 2 ounces of POE oil. POE is compatible with PAG, and adding a couple of ounces of oil to a system with a leak is not a problem.

Follow the instructions from the manufacturer.

bohica2xo wrote: ↑Sat Jun 08, 2024 6:45 am Dye charge cans have been around a long time. Not a problem. As long as they have only Dye

I have used such "refrigerant and dye only" cans in the past.

Most recently (2018) I've used PAG oil that already contains dye when the system was open.

‘Sold everywhere’.

Yep. But that does not equate to ‘good’.
Read carefully. If it says ‘leak stop’, walk on by. That stuff will clog and ruin your system. Most pro shops will not even connect their gauges

OP, you can purchase fluorescent dye in small, unpressurized containers without oil, refrigerant, or other additives. You'll need an injector tool for adding it to the system, though. ACKits.com, this Forum's sponsor, carries both.