---
product_id: 506221705
title: "FJC 4923 UV Dye - 1 oz."
price: "€ 54.58"
currency: EUR
in_stock: true
url: https://www.desertcart.nl/products/506221705-fjc-4923-uv-dye-1-oz
store_origin: NL
region: Netherlands
---

# FJC 4923 UV Dye - 1 oz.

**Price:** € 54.58
**Availability:** ✅ In Stock

## Quick Answers

- **What is this?** FJC 4923 UV Dye - 1 oz.
- **How much does it cost?** € 54.58 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.nl](https://www.desertcart.nl/products/506221705-fjc-4923-uv-dye-1-oz)

## Best For

- Customers looking for quality international products

## Why This Product

- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Description

FJC 4923 UV Dye - 1 oz.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Manufacturer | FJC |
| Brand | FJC |
| Model | 4923 |
| Item Weight | 1.47 ounces |
| Product Dimensions | 2.7 x 1 x 0.9 inches |
| Item model number | 4923 |
| Manufacturer Part Number | 4923 |

## Images

![FJC 4923 UV Dye - 1 oz. - Image 1](https://m.media-amazon.com/images/I/71Gap0PjAjL.jpg)

## Questions & Answers

**Q: How long does it take for this stuff to show up once it is put into the oil?**
A: It seems to show up almost immediately. Run the system briefly to mix in the dye, and watch for the leak. I found it easier to see if it was not full daylight. I got a nice bright UV flashlight for about $12. Also, a little goes a long way ;-).

**Q: Does this work with all types of fluids?**
A: It should. it has most of the fluids on the label you can put it in. I used it for an oil leak.

**Q: will this work for brake fluid?**
A: You have to distribute this throughout your brake system.  How?  since you asked :)  Add 1/4 bottle to bottle of brake fluid.  Remove as much fluid from reservoir and replace with dye'd fluid.  Start bleeding brakes until you see dye (using light).  I estimate 5 to 10 brake pumps per caliper.  after 4 calipers flushed, drive or pump brakes (while running)  then UV light system and see.  Havent seen a brake system leak since I forgot to tighten the bleed screw when I was 17! But I have heard of pin holes in highly salted cities like NYC.

**Q: can i use it for smoke machine, especially for the purpose of finding EVAP leakage?**
A: Short answer, I don’t think so.
Long answer- 
It would be helpful if you clarify the intended use. Are you talking about a theatrical smoke machine or, an HVAC system?
If the latter, it is made to be put in with the refrigerant. Then you can see leaks in the system with an ultraviolet light. I can’t imagine how you would use this with smoke.
Also pretty sure you wouldn’t want to breathe it. 
In general , this product works. I use it to find engine oil and power steering leaks on cars. 
First thing I found was that a little bit goes a long way. I over used it at first. Start with a fraction of what you think you need and then add more if necessary.

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*Product available on Desertcart Netherlands*
*Store origin: NL*
*Last updated: 2026-01-23*