Last Updated on April 20, 2020 by Tim
The question of whether you should try to repair or replace your floor jack is actually a fairly common one for any relatively expensive tool. Even with correct use and routine maintenance, an automotive jack will eventually be in need of repair or replacement.
Hydraulic jacks are pretty basic when you break it down. Each jack has 6 main components:
- Reservoir – holds hydraulic fluid
- Pump – Draws hydraulic fluid on every UP stroke of the handle and then creates pressure on every DOWN stroke.
- Check Valve – Allows pressurized fluid from the down stroke to flow to the master cylinder while “checking” off the return port so the fluid cannot flow back.
- Master Cylinder – Fills with hydraulic fluid.
- Piston – Pushed up or outwards due to the hydraulic fluid that fills the master cylinder.
- Release Valve – Once it’s time to lower the jack and return the piston back to the master cylinder, the release valve is opened to allow the fluid to drain back to the reservoir to start the process again.
For a more detailed explanation of how a floor jack works, click here.
Jack does not fully extend or slowly drifts down – Most likely, there is a small leak somewhere which has caused hydraulic fluid to leak out over time. Depending on the leak, you can simply top off the hydraulic fluid or you may need to repair.
Wheels are squeaky or appear damaged – You may need to lubricate the wheels or possibly replaced the damaged wheel(s). Fortunately, replacement wheels are sold for most major brands and are easy to replace yourself.
Frame is damaged – Jacks may seem indestructible but if you notice the frame is cracked, bent, or noticeable damaged, it’s not safe to use anymore and will need to be replaced (do not attempt to fix).
Oil appears milky or foamy – Somehow, water has made its way into the system and will slowly damage the jack from the inside, eventually beyond repair.
Handle kicks back – If the handle kicks back up after a down stroke, stop using it immediately as this can be very dangerous. This issue may be repaired by a professional.
Repair or Replace?
Typically, this depends on the value of the jack. If you have a $100 jack from Harbor Freight, it would make no sense to take it to a hydraulic jack repair shop which would cost more than a new comparable jack. But the case may be different for higher end brands such as Hein-Werner or Milwaukee.
It’s really a similar argument as when you’re trying to determine whether to replace or resurface brake rotors. Unlike repair manuals for cars, there’s no manual to repair various brands of jacks so getting the pros to help is the only option.
Sometimes buying just the hydraulic unit or other floor jack repair parts and replacing it yourself would make sense. Companies such as Gustin Hydraulics, HCRCnow.com, and others have a wide range of replacement parts. Figuring out how to fix a floor jack is often a matter going to the manufacturer’s site or doing some Googling.
Ted Tyson says
Milky fluid could also mean that someone added brake fluid to the jack after it had
Leaked. Brake fluid will turn neoprene seals in to mush, allowing them to weaken, crack crumble and eventually end up as chunks in your pump. Never use brake fluid in a hyd pump…if your not sure just take a whiff…if its brake fluid you’ll smell it
LUIS R TEODORO says
My 2 ton floor jack is a dual pumper. Now the jack is not properly working due to going back to the rest position with any load (light or heavy) after pumping it and the release valve is close when pumping.
Easiest thing you can do is to make sure your hydraulic oil is topped off. Here is a good guide: https://www.youtube.com/watch?v=Zq75zX8U2L0
After topped off and you notice it leaking, you probably have a failed seal. Depending on how old the jack is, you may actually be better off replacing the jack at this point.
Hey there, I’ve got an awesome 2 ton Hein-Werner that leaks down. Who would you recommend to rebuild? I live in the San Diego area.
I’ve heard some good things about Hogan’s Hydraulics in Lakeside from a couple car forums I belong to but other than them, I couldn’t recommend anyone in particular.
If you want to attempt yourself, YouTube is usually enough in many cases.
Since most modern jacks are made in China, repairing is a waste of money. I just plan on spending a couple hundred on a brand new model every few years. Makes the decision easy.
Joseph Jancewicz says
The safety relief valve on my trolley floor jack needs to be readjusted because someone ignored the “Do Not Adjust” now I need to know how to get it right. I called several hydraulic repair shop and no one wants to look at it. Any help would be appreciated.
Sean Lin says
My hydraulic floor jack jacks up very slowly, it would take a lot of pumping to get it all the way up. The jack will go all the way up, stay up, and come down like normal and there’s no leak. I’ve fill the jack full with hydraulic oil. I’m not sure what the problem is. Do you guys have any ideas what might be causing this problem?
It’s possible you have some air trapped in the reservoir. Check out this thread and see if it applies to your situation: https://www.garagejournal.com/forum/showthread.php?t=52078
I have a american forge jack model 350ss 3.5 ton double pump bottle ,lifts load good but will slowly go down.have a leak some were in hyd.circut. could you suggest what to look for or adjust .I have bleed air out.Thanks
Greg Valant says
How do I replace the Release Valve on my Torin PROFORMANCE 1.5 Ton Aluminum Racing Jack, which is identical to the “US General” and the “Pittsburg Racing” models. I can’t find any maintenance / repair manuals that show how to remove the valve stem from the hydraulic body. The universal joint broke and the entire valve stem needs to be replaced.
Jeremy Collins says
Does anyone know what kind of jack the teal one is in the picture i have one just like it and need to know the brand to get seals and orings