Diagnosing/repairing a hydraulic jack

[Elkins45]

I have a floor jack that’s malfunctioning. It was purchased from Walmart several years ago so it’s certainly not a high quality unit, but I would like to get it back into service if possible. It will rise easily when unloaded, and will start to bear the weight of the vehicle a bit, but once it unloads the springs a tad it won’t life any further.

When it first started doing this I could “reset“ it by fully raising it, barely opening the valve and then standing on it so it slowly lowered. Sometime it took a couple of tries before it would start lifting again. I tried to use it today and it wouldn’t life even after several up and down cycles.

Any suggestions on troubleshooting? I know absolutely nothing about the inner workings of hydraulic jacks other than understanding the basic principles of hydraulics from a physics perspective.

 

[Pew]

Try filing up the fluid and bleeding it:

How To Properly Bleed a Floor Jack - Garage Lift Equipment

Regardless of the make or model of the floor jack, some maintenance is required. After extensive use lifting cars, trucks, or other vehicles the pumping action on floor jacks over time can allow air into the hydraulic pistons or cause a small amount of jack oil to leak out. This can cause the...

www.powerbuilt.com

 

[TomYoung]

Guessing it is a Chinese unit. You said it was not a high quality unit and not expensive. You need to get a new jack from Harbor Freight and toss this. I love thrift, but there is a line to be drawn somewhere, and this is definitely over that line.

 

[Soft Cars]

I got the Daytona Super Duty from HF. It's built pretty stout. At the time I bought it, it was a $100 less than what they want for it now.

All the popularity has forced the price up. I got it when it first came out.

 

[ajchien]

Got a picture of the jack? I’m curious what model it is.

 

[D60]

I was recently looking for parts for my trans jack and these guys were crazy responsive.

I don't think they can help with diagnosis, but might source parts if you figure out what you need.

Lazzar's Floor Jack & Hydraulic Cylinder Repair Part Supplier : Sells Seal Kits for Floor Jacks : hcrcnow.com

Lazzar's HCRC is a leading supplier of repair parts and seal kits for floor jacks, air hydraulic pumps, hand pumps and rams. We also sell Metric and Standard Seals.

www.hcrcnow.com

For jacks with a single hole/plug ya gotta open the valve, push handle down, fill the single hole, close valve and bring handle up. This will "suck" fluid in. Repeat.

Otherwise the Husky "hybrid" 3T is still $129 and I gotta say -- I really like it. It rolls easily and is fairly compact for a 3T jack

 

[Elkins45]

Got a picture of the jack? I’m curious what model it is.

MVP Superlift

 

[ajchien]

MVP is a brand that is no longer around. I believe they got bought by Shinn Fu, and some of their products have been re branded as Pro-Lift now.

The jack design you have is fairly low cost. I think I would do what Pew/TomYoung suggested above. That is, check the oil level and if it’s low, refill and re test.

If it is not low on oil, then potential reasons that it won’t lift up include a release valve that is not sealing tightly, an overload valve that is not set correctly (usually hear a “whoosh” sound while pumping), a main lift arm seal that has failed, or the oil transfer check valves aren’t sealing right. Usually folks take apart the jack to replace all the seals, and inspect the ball valves/valve sets for corrosion.

I think your time/money is better spent on a new jack and then tearing that one apart as a learning experience.

Here is someone’s video tearing down a jack similar to yours (there is also a part 2) …