do floor jacks leak down or are they not supposed to?

[The motor guy]

Years ago I bought a craftsman 3 ton floor jack and even new it always bled down a bit. Recently I bought a newer smaller low profile jack and that thing has held my trailer up since monday and hasn't dropped at all. It does have a jack stand underneath and I did expect it to slowly lose that half inch or height and rest on the jack stand, but it never did. Guess all these years that craftsman was defective

 

[Astro14]

If they are working properly, no, they don’t leak down, but a seal can fail, often suddenly, and they will come down quickly when that happens. Glad you have a stand under there as well. I trust jacks so little, that I let the car down until the stand is taking the weight, and then use the jack as the back-up, by closing the valve, with the weight still on the stand. Never trust a hydraulic jack.

 

[ATex7239]

If they are working properly, no, they don’t leak down, but a seal can fail, often suddenly, and they will come down quickly when that happens. Glad you have a stand under there as well. I trust jacks so little, that I let the car down until the stand is taking the weight, and then use the jack as the back-up, by closing the valve, with the weight still on the stand. Never trust a hydraulic jack.

Yep. I do this as well. Jack is the backup to the jack stand.

 

[D60]

IME it's 50/50 at best. But in a perfect world, no, they shouldn't leak down. My Sunex held up the rear of a SxS for months, but that's a relatively light load.

I don't worry if they do leakdown overnight as they're not meant to be a load holder, but rather just a temporary load elevator.

 

[The motor guy]

IME it's 50/50 at best. But in a perfect world, no, they shouldn't leak down. My Sunex held up the rear of a SxS for months, but that's a relatively light load.

I don't worry if they do leakdown overnight as they're not meant to be a load holder, but rather just a temporary load elevator.

Yeah, I mean it held long enough to put a jack under whatever I needed. Funny thing is it's not leaking down now. Guess it's behaving now since I bought a replacement to keep in the truck

 

[SammyChevelleTypeS3]

If they are working properly, no, they don’t leak down, but a seal can fail, often suddenly, and they will come down quickly when that happens. Glad you have a stand under there as well. I trust jacks so little, that I let the car down until the stand is taking the weight, and then use the jack as the back-up, by closing the valve, with the weight still on the stand. Never trust a hydraulic jack.

That is exactly how I always operate if jacking a vehicle is needed. Better safe than sorry. Stuff happens when we least expect.

 

[The motor guy]

That is exactly how I always operate if jacking a vehicle is needed. Better safe than sorry. Stuff happens when we least expect.

This new jack has a smaller pedestal on it. Or whatever it's called. Makes me nervous that it might slip off

 

[D60]

Yeah, I mean it held long enough to put a jack under whatever I needed. Funny thing is it's not leaking down now. Guess it's behaving now since I bought a replacement to keep in the truck

IME it's also common that a leaky jack will vary in severity of bleed-down from day to day. A million variables there...

 

[The motor guy]

IME it's also common that a leaky jack will vary in severity of bleed-down from day to day. A million variables there...

Technically you're supposed to go all the way up and then all the way down periodically to bleed any air out. That's what it said in the manual of that craftsman jack if you notice bleeding down

 

[BHopkins]

I've never had a car on a floor jack long enough to find out if it would leak over time. My use of floor jacks has always been to lift a vehicle long enough to position jack stands, then lower the car to rest on the jack stands.

It seems a little iffy to work under a car that is supported by a column of hydraulic fluid, being held in place by a valve of some sort, and a seal around the piston.

 

[The motor guy]

I've never had a car on a floor jack long enough to find out if it would leak over time. My use of floor jacks has always been to lift a vehicle long enough to position jack stands, then lower the car to rest on the jack stands.

It seems a little iffy to work under a car that is supported by a column of hydraulic fluid, being held in place by a valve of some sort, and a seal around the piston.

I have always said, hands stay at 9 and 3 when putting tires on. They won't get smashed by the wheel well, and won't get crushed if you have them underneath and it comes down.

 

[D60]

I have always said, hands stay at 9 and 3 when putting tires on. They won't get smashed by the wheel well, and won't get crushed if you have them underneath and it comes down.

Then I fail because I have a technique of lifting the tire with my foot (toes) while guiding with my hands. Although 99% of the time this is on my 2-post I do always wear steel toes.....