Unscrewed the "DO NOT ADJUST" port from HF Jack (2 tons) - help!

[RandomUserOnInternet]

Hey guys, nice to meet you.
I am kinda lost and don't really know what to do. I was cleaning my 2 tons - HF Jack and i unscrewed the pressure port within the cover screw with the name "DO NOT ADJUST". I did not count the number of revolutions and now i don't know how to adjust it.
Could you please help me? What should i do?

 

[tipsy]

Welcome! If I'm understanding you correctly. As long as no fluid leaked out that pressure port screw is closed tight or screwed all the way in for lifting and then cracked open just enough to release pressure and lower the jack.

 

[rlitman]

The "do not adjust screw" sets the spring pressure on the bypass. That prevents you from exerting more pressure on the ram than the jack can sustain. Set wrong, the jack can fold up on itself when used on too heavy a vehicle, or lower itself unexpectedly.

 

[RandomUserOnInternet]

Welcome! If I'm understanding you correctly. As long as no fluid leaked out that pressure port screw is closed tight or screwed all the way in for lifting and then cracked open just enough to release pressure and lower the jack.

Hey pal, thanks for replying!
I'm referring to this (take a look at the image)

 

[RandomUserOnInternet]

The "do not adjust screw" sets the spring pressure on the bypass. That prevents you from exerting more pressure on the ram than the jack can sustain. Set wrong, the jack can fold up on itself when used on too heavy a vehicle, or lower itself unexpectedly.

Hey pal, thanks for commenting!
How can set it properly? What should i do in order to avoid that strange behaviour?

 

[htmdude57]

Put your jack on a test stand that can display force exerted in lbs. If your jack is rated at 2 tons, pump it up to just over 4000 lbs of force. Adjust relief to start bleeding off (bypassing) the oil. Retest it to check that it can lift 4000 lbs, and bypasses when you exceed that force.

 

[RandomUserOnInternet]

Put your jack on a test stand that can display force exerted in lbs. If your jack is rated at 2 tons, pump it up to just over 4000 lbs of force. Adjust relief to start bleeding off (bypassing) the oil. Retest it to check that it can lift 4000 lbs, and bypasses when you exceed that force.

Hey!
What if i don't have any "test stand"?

 

[htmdude57]

Don't unscrew the screw under the cap that says "Do not adjust".

 

[RandomUserOnInternet]

Don't unscrew the screw under the cap that says "Do not adjust".

Yeah, it was all covered by some dust + oil and did not see it :/. That was silly . Is there anything like "for 2 TONS HF Jacks it is necessary to give 4 revolutions"?

 

[htmdude57]

They need to put this kind of sign on it:

 

[RandomUserOnInternet]

They need to put this kind of sign on it:

Lol, seriously. How can i adjust that screw again without a test stand? How many revolutions? I guess there are millions of HF Jack 2 tons around the world

 

[htmdude57]

Maybe you could take it to a hydraulic repair shop? Maybe you might get lucky, and the guy would do it for you cheap or free? But he might also say that a HF jack it isn't worth his minimum shop charge to do the job?

 

[Zeke]

Where was this screw? I've never seen one.

 

[RandomUserOnInternet]

Where was this screw? I've never seen one.

Take a look

 

[mike93lx]

Lol, seriously. How can i adjust that screw again without a test stand? How many revolutions? I guess there are millions of HF Jack 2 tons around the world

Replace it.

It's amazing how everyone thinks there must be work arounds...especially on something you are asking to hold 2 tons up in the air

 

[rlitman]

Put your jack on a test stand that can display force exerted in lbs. If your jack is rated at 2 tons, pump it up to just over 4000 lbs of force. Adjust relief to start bleeding off (bypassing) the oil. Retest it to check that it can lift 4000 lbs, and bypasses when you exceed that force.

This exactly. A hydraulic press that has a gauge could serve as your test stand. That might be easier to find than a hydraulic repair shop.

 

[RandomUserOnInternet]

Replace it.

It's amazing how everyone thinks there must be work arounds...especially on something you are asking to hold 2 tons up in the air

It is not in the air by itself.. i use axle stands too

 

[mike93lx]

It is not in the air by itself.. i use axle stands too

So the car floats its way up there to get the stands under?

 

[Zeke]

I have 3 chinese floor jacks, only one from HF, the so called racing jack. It doesn't lift much before it strains. I use it under low cars to get them started and then put a 3 T jack under there. None of these jacks have anything that looks like that. When I need to put more than 50 lbs (est) on the end of the handle, I get a 2nd jack. I've never had a jack refuse to work when pumped no matter what. I started out many years ago with a Hein Warner that was tweaked due to someone letting a car roll off sideways. It was always a bit biased and I got rid of it. I think it was rated then at 1-1/2T and I used it on everything.

None of my jacks are less than 20 years old. I have 4 bottle jacks that I have leaned on pretty hard under houses and they don't have that screw either. Good thing they come with short handles.

 

[RandomUserOnInternet]

So the car floats its way up there to get the stands under?

Yeah, after that the jack is removed

 

[RandomUserOnInternet]

I have 3 chinese floor jacks, only one from HF, the so called racing jack. It doesn't lift much before it strains. I use it under low cars to get them started and then put a 3 T jack under there. None of these jacks have anything that looks like that. When I need to put more than 50 lbs (est) on the end of the handle, I get a 2nd jack. I've never had a jack refuse to work when pumped no matter what. I started out many years ago with a Hein Warner that was tweaked due to someone letting a car roll off sideways. It was always a bit biased and I got rid of it. I think it was rated then at 1-1/2T and I used it on everything.

None of my jacks are less than 20 years old. I have 4 bottle jacks that I have leaned on pretty hard under houses and they don't have that screw either. Good thing they come with short handles.

My HF Jack did not even come with a manual :/

 

[mike93lx]

Yeah, after that the jack is removed

Nice! A magic jack

 

[Kenstone1]

My HF Jack did not even come with a manual :/

All the jacks sold by HF today have the manual pdf file in the listing on the HF site.
You might find the info you need there...
jmo,
.

 

[APEowner]

First I'd look carefully at the screw and see if there are any witness marks that you can use to see how far in it was threaded. If there aren't then I'd slowly adjust it in until it will just bearly lift up your car. Assuming your car is under the rated weight capacity of the jack you'll now have a jack that can do what you need but is safely adjusted below the original capacity.

 

[Zeke]

Once something is calibrated it shouldn't be messed with. No test stand, drive a truck over the scales and get the weight of the heavy end. There are ways to multiply leverage.

Me, I'd be buying a new 2nd jack and use the old one as a back up holding trannys and such. One jack is never enough.

 

[driftpin]

I think I'd scrap the jack, chalk it up to 'life's lesson learned,' and be glad you are still alive. Sure you can mess with it, but it's a frickin' HF jack, and a brand-new HF jack isn't gonna be too-many simoleons. People die all the time from using sub-standard equipment for the job they're attempting to accomplish. 'Don't be that guy.'

 

[ChefRex]

Sir, drop the tools and walk away from the vehicle

 

[oldmachinenut]

Tighten it back down in small steps testing it each time by lifting the front of your vehicle. Repeat the steps until it lifts the vehicle without bypassing. This will most likely set it to a lower relief pressure than it originally had. The only dangerous thing to do would be to bottom that screw out and hydraulically exceeding the capacity of the rest of the jack.

 

[snyder]

Will you be using the jack to lift over 4,000 lbs.. if not , run that screw all the way..

 

[Samh]

Go buy another HF jack like, and take out that screw that says do not adjust, but count the revolutions this time /sarcasm.

 

[paulsomlo]

Try running the screw in all the way, then back it out 1 1/2 turns, see how it performs. If it can't raise a reasonable load, then tighten it little by little.

 

[RandomUserOnInternet]

Try running the screw in all the way, then back it out 1 1/2 turns, see how it performs. If it can't raise a reasonable load, then tighten it little by little.

I will, pal!

 

[racecougar]

Be advised that following that advice may set the bypass higher than the jack arm/frame is capable of withstanding, which can absolutely cause a fatal situation if things go sideways.

 

[mike93lx]

Be advised that following that advice may set the bypass higher than the jack arm/frame is capable of withstanding, which can absolutely cause a fatal situation if things go sideways.

But hey, it's a suggestion, so run with it, right?

 

[Kenstone1]

Hey pal, thanks for commenting!
How can set it properly? What should i do in order to avoid that strange behavior?

Most jacks when topped out (fully extended) any further pumping will hit that bypass valve.
The amount of force on the pump lever to actuate that bypass valve can be used as a "gauge" to determine the setting of the valve.
That lever pressure could be "gauged" on a jack that has not been adjusted and duplicated on the jack that is out of adjustment.
jmo,
.

 

[firebirdparts]

This thread makes me sad.

OP, I feel for you, having to sort through this condescending drivel. At least we do have the ignore feature.

 

[PoorUB]

If it were me I would stick the jack under the heaviest car or pickup I have, assuming it is under the jacks rating. Back off the screw and try jack up the vehicle. Keep screwing in the adjustment until the jack will pick it up, then maybe one more turn.

The front end of a 1/2 ton pickup should be maybe 2500 pounds so you will well under the 2 ton limit of the jack.

Try running the screw in all the way, then back it out 1 1/2 turns, see how it performs. If it can't raise a reasonable load, then tighten it little by little.

I would advise not doing this. You have not idea where that setting might be. You maybe well over the rating of the jack. Doing it like this it probably will lift the load just fine, but that doesn't mean it isn't set way too high.

Start with the screw farther out, set too light. If it will not lift a known load, then run the screw in and try again.You want to jack to not left your load and then adjust the setting in untill it does and then perhaps another turn.

 

[rslaback]

It would take a little bit of rigging but if it was me I would set that bypass tension off of another jack in the same way that you can use a calibrated torque wrench to ballpark calibrate another.
If you can find another 2T jack and place the two so that they are in series you can adjust the screw to the point where the calibrated jack starts to bleed off instead of the questionable one, then turn back just a bit.

 

[gregs]

I

If it were me I would stick the jack under the heaviest car or pickup I have, assuming it is under the jacks rating. Back off the screw and try jack up the vehicle. Keep screwing in the adjustment until the jack will pick it up, then maybe one more turn.

The front end of a 1/2 ton pickup should be maybe 2500 pounds so you will well under the 2 ton limit of the jack.


I would advise not doing this. You have not idea where that setting might be. You maybe well over the rating of the jack. Doing it like this it probably will lift the load just fine, but that doesn't mean it isn't set way too high.

Start with the screw farther out, set too light. If it will not lift a known load, then run the screw in and try again.You want to jack to not left your load and then adjust the setting in untill it does and then perhaps another turn.

This is what I would do if I was in the same situation. One of the problems with overloading it is having the u-cup seal failing on the piston.

 

[imagineer]

IMO, this is a situation where you need to accept the goof-up as a lesson learned, and go get a new floor jack.

Recover all the usable hardware, material, casters, etc. from the messed up jack and just throw out the carcass.