DIY: Floor Jack O-ring Rebuild

[cn90]

There is lack of info on hydraulic floor jack rebuild in forum, so I decide to write a short DIY.

If you fix your floor jacks, please share your photos etc. Make sure you post brand name of the jack and photos.


Some background info:

- My local tire shop uses Snap-on floor jack ($500-$600/each), and even with Snap-on and the amount of cars they jack per day, the shop owner tells me the jack usually lasts one year, then it won't lift the vehicle (INTERNAL leak). But he never has an EXTERNAL leak from Snap-on. The shop owner usually buys another cylinder ("hydraulic ram")for $250.
If you have this problem: you can still rebuild it using appropriate kits/O-rings, search youtube for DIYs for INTERNAL leak.

- My problem with Harbor Freight 2-ton jack is the opposite: it always lifts the car but oil starts leaking after 6-12 months. I have tossed a few of these cheap jacks over the years. This is jack #4 during the last 10 years. Sears, Torin are not better since they come from the same factory.
Reading review online tells me that the EXTERNAL leak has to do with O-ring and nothing to do with the price of the jack, whether it is HF Pittsburgh, Sears, Torin, or Lincoln etc.

- I don't want to dump more stuff in the landfill if I don't have to. So I decide to tackle this project. I am glad I did this rebuild: less waste in the landfill sites!


PARTS + TOOLS:
- O-ring set from HF: $5
- Hydraulic Oil: $5
- Adjustable wrench, screwdriver, snap-ring pliers.

PROCEDURE

1. First, read the attached pdf and study the diagram. Basically:
- Oil flows from chamber A ---> chamber B. There is a 1-way valve to block oil from returning. If you can't lift the vehicle: either the 1-way valve is bad (rare) or the O-rings leak internally (#2 and #3 in the diagram). Conceptually, this is similar to brake master cylinder internal leak!

2. Watch these youtube videos:


LARGE O-ring:





SMALL O-ring:





3. The Oil Chamber (reservoir) is #21. Oil leak is prevented by:
- Teflon O-rings #20, #23. These Teflon rings are very robust and should not leak at all.
- O-ring #19: this was my problem. After a few days in the garage (not using jack at all), it leaks from the O-ring: a few drops on the floor.

Factory O-ring is: 21 x 3 = 27 mm total.
I used O-ring with: 20 x 4 = 28 mm total: zero leak afterward!

3. Undo the nuts and separate the 2 halves of the jack.

4. Undo the circlips holding the arm.

5. Undo the spring. During re-installation, you need to wear goggles and use the spring tool to hook it back up.

6. Things are self-explanatory. Don't forget to refill with new oil and bleed it (search you tube for bleeding procedure).

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[cn90]

Below is a nice animation of how a typical hydraulic jack works.
The hydraulic system basically uses Pascal's Law.

Once you understand how it works, you can simply rebuild it.

As I mentioned above, there are 2 kind of leak:
1. EXTERNAL Leak: oil on the floor even when you don't use it.
2. INTERNAL Leak: you can't lift the vehicle...this rebuild is more extensive but doable with appropriate kits.
Actually once the cylinder is opened as in my photos above, the master cylinder O-ring is right there.
So not much more time involved.
However, finding that O-ring (part numbers #2 and #3) may be a challenge.

[scot850]

I think this is a good idea, but when I contacted the UK supplier of my 25+ year old Sealey branded unit they told me the replacement parts are no longer available for some reason!! Mine has been a faithful old unit that has followed me around the UK and now lived in my garage in Canada for the last 16 years but now has become incontinent and loses pressure. I love this compared to the new low profile unit I bought from Costco which is a royal pain as it sits so low that if I put cardboard down for messy jobs it grounds and won't move. The wheels also have poor quality bearings for rotating. Finally, discovered you can't replace the jacking pad as it is a non-standard size, so the rubber seat pads I have won't fit.

Neil.

[cn90]

- I think you can find Sealey jack rebuild kit on the web. I just searched and saw some Sealey rebuild kits from the UK.

- I recycle stuff at home, I am a "green" guy and therefore hate throwing stuff in a landfill site. As mentioned above, I have thrown out 3 of these cheap jacks over the last 10 years with the only defect being an external leak! This time, I say no to waste. BTW, most of these jacks come from the same factory, only having different names on it (Torin, Sears, Napa, AC Delco, Pittsburgh, to name a few).
In theory, I can say to myself: "throw it out get another cheap one for $30."
It is not about waste but it is a matter of principle: when it can be fixed, I will fix it.

- I used to look at hydraulic jack and was intimidated by it simply b/c I didn't know the anatomy and how it worked. Only after I studied it in detail (checking parts diagram and watched some youtube videos), it appears to me that this is easier than replacing an axle or brake in my Volvo. The challenge is not in the procedure but rather where to find parts!

- Luckily, most of the time, the defect is simply a leaking O-ring and as mentioned above, you can use standard O-ring from the $5 kit. Or measure your particular jack O-ring size and find it at local hardware store. You will find that the repair is satisfying b/c you know you do the right job. You also save the earth from unnecessary waste. Plus you have a few extra O-rings for the "next time".

[scot850]

Totally agree with the philosophy. I am also of why replace if it can be fixed, unless it gets to the point where the repair is getting as much as a new one. Some stuff just can't be replaced as parts are obsolete.

I have had a look for the seal kit, and chances are the new model is just the same as the old one but 25 years newer. They change the model number and sometimes color but they often look identical.

This is on the winter project not just because I think it can be fixed, but as I like the jack and think it is way better made than the newer stuff today. That is why it is not in the trash pile.

All the videos and links are handy and will be studied again nearer the repair time.

Thanks for taking the time to assemble and share the info.

Neil.

[erikv11]

This is a great idea. If you're going to the trouble to open up and repair a jack, I'd highly recommend spending a few bucks on better quality o-rings. Go to a machine supply shop and tell them what you are using them for, they will size the old ones and give you something made from actual rubber not plastic. Those plastic (or whatever compound it is) ones will be shot within a year, the cheap ones (including most single-sale o-rings from any hardware store) are utter crap, unfortunately. I've learned that the hard way.

@scot850 I was feeling good because my old Costco floor jack is going on 12 years and hasn't leaked a drop, I was at first thinking to post something like "or buy a quality jack and avoid all the hassles." But clearly your Sealey unit is a few cuts above what I've got, I will keep quiet!

[cn90]

I don't have INTERNAL leak (failure to raise the vehicle) but for those of you who have this problem, no worry.

READ the threads below and do a google search on "Loaded U-Cup Seal", which is basically U-Cup (probably made from Teflon) with the inside loaded with an O-ring and this is it.
When you jack it up, oil is pushed into the cylinder, expanding the O-ring, which in turn pushes on the U-Cup Teflon ring outward to form a tight seal.
In addition, the weight of the car pushes the piston back into the chamber, increasing the pressure in the U-Cup Teflon ring.

http://www.garagejournal.com/forum/show ... hp?t=58869

http://www.garagejournal.com/forum/show ... hp?t=51105


I copy and paste the photos from that thread so you can see the "Loaded U-Cup Seal" design.
If you can source both the U-Cup and O-ring, then replace both.
If you cannot find the U-Cup, then a new O-ring usually solves the problem, simply b/c O-ring wears out (hardened with time and fails to expand), while the U-Cup Telfon design should last much longer than the O-ring itself.

[mecheng]

Scotty Kilmer uses ATP-205 to fix his jack, after using it myself I am a believer, worth a shot to save a lot of work

[abscate]

By the way, there is no reason to send anything metal to the landfill. Im lucky and have a scrap metal recycler 5 minutes from my house. I routinely cash in about $100 bucks a month of scrap washers, grills, brake drums whatever people throw away. Sometimes I pick up an extra 500 pounds of stuff on the way!

[cn90]

Agree re metal recycling.

I am working on a small project: I will study all the seals in a typical 2-ton floor jack.
I have a local hydraulic shop and they sell good USA-made seals, O-rings.

When I look at the more expensive floor jacks such as Hein-Werner ($400-$500) or Snap-on ($500-$600), their seals/O-rings last longer. But they will eventually leak like anything else under the sun. Do I want to spend $500 on a floor jack? No.

On the metal parts: Hein-Werner or Snap-on jacks are sturdier but the HF jack metal parts are not bad either.
This is because the metal parts are basically metals parts, but it is the seals/O-rings that define the longevity of the jack.

My point is: Harbor Freight $25 2-ton Chinese-made jack + USA seals/O-rings (I can get them for $10) = $500 jack lol.
Basically the "best of both worlds".

I will post an update later.