



🛠️ Stop leaks before they stop you — keep your projects flowing smoothly!
Bar's Leaks Jack Oil with Stop Leak is a 12.5 oz hydraulic fluid additive designed to stop and prevent leaks in all types of hydraulic jacks and snow plow fluids. Its non-corrosive, non-clogging, and non-foaming formula is compatible with petroleum-based, mineral oil, and synthetic fluids, ensuring reliable performance and extended equipment life. Trusted by professionals and DIYers alike, it offers a cost-effective solution to maintain hydraulic systems without costly repairs.





| ASIN | B0002KKIBY |
| Best Sellers Rank | #2,795 in Automotive ( See Top 100 in Automotive ) #72 in Diagnostic, Test & Measurement Tools |
| Brand | Bar's Leaks |
| Customer Reviews | 4.7 4.7 out of 5 stars (3,655) |
| Date First Available | July 7, 2004 |
| Global Trade Identification Number | 00046087000441 |
| Is Discontinued By Manufacturer | No |
| Item Form | Liquid |
| Item Weight | 12.6 ounces |
| Item model number | HJ12 |
| Liquid Volume | 12.5 Fluid Ounces |
| Manufacturer | Bar's Leaks |
| Manufacturer Part Number | HJ12 |
| Material | Plastic |
| Model | HJ12 |
| Number of Items | 1 |
| Package Information | Bottle |
| Product Dimensions | 6.6 x 3.6 x 3.4 inches |
| Recommended Uses For Product | Anti-wear |
| SAE J300 Viscosity Grade | 10W |
| Specific Uses For Product | Repairing and maintaining hydraulic jacks and snow plow equipment |
| UPC | 046087000441 |
| Unit Count | 12.5 Ounce |
| Viscosity | 10w |
M**E
Easy choice for quality and value.
Refilled a hydraulic pump and there were no issues. No new leaks or viscosity issues. Thickness and smell and use in a 10-ton press is going just as expected - no problems.
J**.
Works well!
Good stuff, worked well in my old Craftsman jack
P**O
Quickly cured bad clutch master cylinder!
The clutch master cylinder failed on my 2012 Ford Focus. It leaked internally, causing the pedal to sink to the floor without disengaging the clutch, but with no loss of brake fluid. The same reservoir is used on the Focus to hold fluid for the brakes and the clutch. Bars Leaks jack oil with stop leak must NOT be put into the brake system reservoir because it can affect the boiling point of brake fluid and the viscosity thereby causing problems with the ABS system. Also, it will not mix with brake fluid. My solution was to segregate the clutch hydraulics from the brake system. I purchased from Amazon a Lefossi universal reservoir for motorcycle brake systems. I mounted this reservoir on the side of the battery box. I also bought from Amazon some 150 cc plastic syringes for fluid transfer. I cut the fluid line from the brake master cylinder reservoir to the clutch master cylinder fluid intake nipple. I plugged the output nipple on the brake master cylinder reservoir. I ran a hose from the remaining section of the fluid supply line to the clutch master cylinder up to the Lefossi reservoir. I then vacuumed out the remaining residual brake fluid in the clutch system using a manual brake vacuum pump which can be purchased from Amazon, by connecting the vacuum pump to the clutch bleed nipple. After that, I used the syringe to pump the Bars Leak jack fluid into the clutch bleed nipple. This filled the clutch hydraulic system and automatically bled the system of all air. I pumped in just enough jack fluid to fill the Lefossi reservoir (this is called reverse injection). Then I closed the clutch bleed nipple. The result, it took about 15 hours or so for the Bars Leak jack oil to do its magic and then the clutch worked perfectly! Bars company claims you should allow up to 3 days for the oil to recondition the seals of a hydraulic jack or snow plow system. They also insist that there are no solvents in the product which can ultimately dissolve the seals. Bars company does not specifically recommend the jack oil for use in clutch systems, and they caution against putting this stuff into the brake fluid in the brake reservoir. It can ruin your brakes, but I got great results with my clutch system after I segregated the brake hydraulics from the clutch hydraulics, and I saved almost $500!
S**2
Normal use
The product performs adequately; there are no major issues.
S**R
Easy fix for a jack low on oil
I've had my floor jack for several years and inevitably they loose oil over time. Topped off the oil with this and have a perfectly working jack again. It's an easy fix and would recommend trying this before replacing.
G**E
good product great price
fluid for hyd jacks
D**Y
Jack goes all the way up again
Was having an issue where my jack stopped rising to full level. Bought this to fill it up and worked great. The nozzle does not fit the hole on the jack, so a funnel with small spout was needed. Great quality. Did not stop my leak, but did get my jack working again when I needed it.
J**Y
Works as advertised and now my hydraulic jack does again, too.
This product worked exactly as advertised and refilled my aging hydraulic automobile jack, just fine. I never noticed leakage. However, after many years of use, I suddenly couldn't raise my tire fully off the ground for rotation or replacement any more with my hydraulic jack as it used to do easily by several inches. After researching this problem on the web, I realized I needed this product or something similar. I only needed a few ounces to completely refill my jack and return it to proper working order, so I have most of the bottle unused, in case I need to add anymore in the future. The included reclosable cap made an excellent refilling funnel when I unscrewed it from the bottle, and inserted it in my jack's oil fill hole. Highly recommended.
A**R
Not fixing the jack problem still not working
A**R
Absolutely incredible product! My floor jack had been slowly leaking down for months and I was ready to toss it and buy a new one. Then I found Bar's Leaks Jack Oil with Stop Leak, and what a difference it made. After topping off the fluid, the jack lifted smoothly again and held pressure like it was brand new. You can see the improvement right away. No more creeping down and no more puddles under the cylinder. The stop leak actually works, and the hydraulic action feels solid and responsive. For such a small bottle, it’s pure magic in a can. I honestly didn’t expect much for the price, but this product exceeded every expectation. It’s easy to pour, works fast, and saves you from having to rebuild or replace your jack. I’ll be keeping a bottle of this in the garage from now on. If your jack is leaking or losing lift, don’t waste time. Get this! It’s the best fix I’ve ever used for a hydraulic issue.
N**N
Fixed my jack easy peasy. No issues.
A**R
One of two of the best jack oils I found but this one was available on Amazon so a no brainer. If it stops leaks I wouldnt know, my jack is new. It's supposed to extend the jacks life and probably does.
L**E
Works as it should
Trustpilot
4 days ago
1 week ago