Hydraulics

[seekermeister]

I need to repair my floor jack, therefore must buy some hydraulic fluid and o-rings. I know from past experience that not all o-rings and fluids are equal, but have not been able to find any specifications for my particular jack. I sent some emails to some suppliers asking about this, but thus far have received no replies.

How does one determine exactly which o-rings and fluid to get? I'm only referring to materials and forumula.

 

[Hopalong X]

$3.39 32oz. > Hydraulic Jack Oil | AutoZone.com

$5.99 32oz. > Buy Coastal AW 32 Hydraulic Jack Oil S3H027/21601 at Advance Auto Parts

$3.99 12oz.> Gunk M33-12 - Hydraulic Jack Oil | O'Reilly Auto Parts

O-rings are available at all three automotive retailers above.

 

[seekermeister]

Okay, thanks. I was going to order them online, but since I'm only a couple of blocks from Autozone, I guess there is no excuse for not going there. Am I to understand that automotive fluids and o-rings are the same as used in hydraulic jacks?

EDIT: Forget the part of the question about the fluid, because I now see that it is specifically jack oil. I thought it curious that while AutoZone is cheaper than what I found online for the fluid, the same isn't true of the o-rings, as can be seen by comparing the links below:

http://www.autozone.com/autozone/ac...s&fromString=search&itemIdentifier=76119_0_0_

http://cgi.ebay.com/ebaymotors/?cmd...49&item=190574969385&sspagename=STRK:MEWAX:IT

 

[Hopalong X]

I would take the old ones in to the store and just match them up to size. You can't need more than 10 total.

Probably only 5-6 max. at about 50 cents each.

 

[seekermeister]

You're probably right, but without actually tearing into the jack, I'm guessing that there are only 3 o-rings involved...1 on the release valve, one on the compression piston and 1 on the output shaft. Does that sound right? Not having the jack apart, I can only guess which seal is bad, because there is no sign of external leakage, only that it doesn't hold pressure.

 

[carwiz]

The pump and cylinder are most likely NOT O-rings. O-rings are not meant to hold high pressure. These will be lipped seals. If there's no external leak, the problem is, more likely than not, just a check ball that's not seating. A way to try and clear dirt from the ball and seat is as follows.

1. Make sure the jack has fluid.
2. Open the release valve.
3. Lift or pull the cylinder up by hand. Let it go down. Repeat this 2-3 times.
4. Close the release valve and see if it will pump.

If it pumps up, I suggest doing the following:
1. Drain the fluid.
2. Fill with Stoddard Solvent (Paint Thinner).
3. Repeat step 2 & 3 above except 4-5 times.
4. Drain the solvent and refill with Jack Oil.

You should be good to go.

 

[Britton30]

I used to work at a NAPA store and we had a place to send jacks in for repair. They came back looking like a new one for $30-$100 depending on the jack.
(Scotty's Hydraulic Jack Service, Indy)
Check with your local AutoParts MegaMart or repair garages to see if some service like that is in your area.

http://www.google.com/#sclient=psy-....,cf.osb&fp=298cfbc9b6f1239a&biw=1920&bih=875

 

[Layback Bear]

If the jack is made i China don't wast your time doing anything.

 

[carwiz]

I've got more floor jacks and bottle jacks in the shop than I know what to do with. All but two came from the salvage yard. They end up in the scrap yard for all the same reason--They don't pump up. I do the quick test and nine times out of ten, they start working. I then buy them for $0.15/lb. (Earlier ones were ten cents a pound.) If there's no sign of leaking, a re-seal is a waste of money. A good cleaning will get them to work again. It's common for paint chips from the fill plug, dirt or bits of rust to get under the intake check ball. Give it try. It costs nothing.

 

[seekermeister]

The pump and cylinder are most likely NOT O-rings. O-rings are not meant to hold high pressure. These will be lipped seals. If there's no external leak, the problem is, more likely than not, just a check ball that's not seating. A way to try and clear dirt from the ball and seat is as follows.

1. Make sure the jack has fluid.
2. Open the release valve.
3. Lift or pull the cylinder up by hand. Let it go down. Repeat this 2-3 times.
4. Close the release valve and see if it will pump.

If it pumps up, I suggest doing the following:
1. Drain the fluid.
2. Fill with Stoddard Solvent (Paint Thinner).
3. Repeat step 2 & 3 above except 4-5 times.
4. Drain the solvent and refill with Jack Oil.

You should be good to go.

I will give that a try, but since it already does pump up, but will not hold sufficient pressure to raise my vehicle, I will have to check it under load.

Just in case that doesn't work, if you are right about the internal seals not being o-rings, I'm wondering if they are user replaceable and where I would find those lipped seals?

 

[seekermeister]

I used to work at a NAPA store and we had a place to send jacks in for repair. They came back looking like a new one for $30-$100 depending on the jack.
(Scotty's Hydraulic Jack Service, Indy)
Check with your local AutoParts MegaMart or repair garages to see if some service like that is in your area.

Google

The jack would cost less than that to replace, so that idea doesn't fly.

 

[seekermeister]

If the jack is made i China don't wast your time doing anything.

Ugh, yes it is made in China, so I guess that it is a waste of time.

 

[seekermeister]

I've got more floor jacks and bottle jacks in the shop than I know what to do with. All but two came from the salvage yard. They end up in the scrap yard for all the same reason--They don't pump up. I do the quick test and nine times out of ten, they start working. I then buy them for $0.15/lb. (Earlier ones were ten cents a pound.) If there's no sign of leaking, a re-seal is a waste of money. A good cleaning will get them to work again. It's common for paint chips from the fill plug, dirt or bits of rust to get under the intake check ball. Give it try. It costs nothing.

Even though I've had this jack about 3 years, I think that I've only used it twice. It almost looks like new, the paint hasn't even been knocked of the wheels.

 

[Britton30]

I agree with Layback Bear on the Chinese issue. There are really nice aluminum floor jacks available for less than $100. Similar to the kind NASCAR pit crews use(also Chinese though)

 

[carwiz]

Yeah, I think it's still the check ball but a leaking pump seal could give you the same symptom. But a leaking seal on the pump will show oil around the plunger. The bodies are cast steel and it's not uncommon for the import products to contain sand or slag. This works it's way into the valve and pump. The check ball lifts to allow fluid into the pump when the handle is raised. When the handle is pressed down to pressurize the cylinder, the check ball is supposed to close. If there's dirt under the ball, it won't seal and the pump pressure leaks back into the reservoir. So there's little or no pressurization of the cylinder.

I don't know of any one that makes a seal kit for the imports. It's just not worth it. They'll be metric and if you do have to replace them, you'll just have to match them up. (I doubt any one will have listings.) Most hydraulic distributors should have the seals. The bearing distributor I use carries a selection of seals too. I think you'll find that replacement seals will cost more than you probably paid for the jack though.

In any case, don't load the jack when doing the clearing. You can't any way--The release valve needs to be open. The procedure is simply to flush fluid back and forth through the pump to dislodge debris from the check ball and seat. After that, then you can load test it. If it holds then do the cleaning procedure because you know it's dirt under the ball.

 

[seekermeister]

I agree with Layback Bear on the Chinese issue. There are really nice aluminum floor jacks available for less than $100. Similar to the kind NASCAR pit crews use(also Chinese though)

Unlike most people, I don't use the floor jack in the garage (don't have one), I keep it in the vehicle in-lieu of a regular jack, because of it's greater ease of use.

The better floor jacks not only cost much more, but they are too heavy and large to keep in the vehicle. However, even though it only cost me ~$40 new, that is still somewhat expensive for a jack that only worked twice.

 

[seekermeister]

Yeah, I think it's still the check ball but a leaking pump seal could give you the same symptom. But a leaking seal on the pump will show oil around the plunger. The bodies are cast steel and it's not uncommon for the import products to contain sand or slag. This works it's way into the valve and pump. The check ball lifts to allow fluid into the pump when the handle is raised. When the handle is pressed down to pressurize the cylinder, the check ball is supposed to close. If there's dirt under the ball, it won't seal and the pump pressure leaks back into the reservoir. So there's little or no pressurization of the cylinder.

I don't know of any one that makes a seal kit for the imports. It's just not worth it. They'll be metric and if you do have to replace them, you'll just have to match them up. (I doubt any one will have listings.) Most hydraulic distributors should have the seals. The bearing distributor I use carries a selection of seals too. I think you'll find that replacement seals will cost more than you probably paid for the jack though.

In any case, don't load the jack when doing the clearing. You can't any way--The release valve needs to be open. The procedure is simply to flush fluid back and forth through the pump to dislodge debris from the check ball and seat. After that, then you can load test it. If it holds then do the cleaning procedure because you know it's dirt under the ball.

I truly hope that you are right, because the alternative is to consign it to the dumpster. I wouldn't mind too much buying a new jack, but I've never had too much luck with hydraulic jacks in the past...probably because I didn't want to pay the price for a good one.

 

[carwiz]

Even the good ones can have this problem over time. I have several old "made in USA" floor jacks put back in use just by doing the same thing. It does work. I hope it works for you. Let me know one way or the other.

Back to work - More sandblasting to do.

TTFN

 

[Britton30]

I think being unused for long periods would be detrimental to a jack. The inner seal may deteriorate or harden or the fluid could absorb water and rust the innards.

 

[seekermeister]

carwiz,

It appears that your tips worked. At least it held pressure for 10-15 minutes after exercising it as you described. I guess that means that I need to wash it out as mentioned and refill it.