Hydraulic jacks
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1. A RESERVOIR to hold hydraulic fluid. | 1. A RESERVOIR to hold hydraulic fluid. | ||
| − | 2. A PUMP that draws fluid from the | + | 2. A PUMP that draws fluid from the reservoir on it's up, suction or intake stroke then creates pressure on it's down/power stroke pushing the fluid through a... |
| − | 3. CHECK VALVE which after allowing fluid to pass from the | + | 3. CHECK VALVE which after allowing fluid to pass from the reservoir to the pump now 'checks' off the return port to the reservoir and directs the pressurized fluid to the... |
4. MAIN CYLINDER where the... | 4. MAIN CYLINDER where the... | ||
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5. RAM PISTON is forced out or upwards as the main cylinder fills with pressurized fluid. | 5. RAM PISTON is forced out or upwards as the main cylinder fills with pressurized fluid. | ||
| − | 6. After the jack has done it's job and it is time to release the pressure allowing the ram piston to return back into the main cylinder THE RELEASE VALVE is opened and the fluid is ported back into the | + | 6. After the jack has done it's job and it is time to release the pressure allowing the ram piston to return back into the main cylinder THE RELEASE VALVE is opened and the fluid is ported back into the reservoir so the jacking cycle can be repeated. |
You might wish to view our 'ANIMATED JACK' showing the Inside of a Working Bottle Jack - You can see it on our INFO Server HERE. | You might wish to view our 'ANIMATED JACK' showing the Inside of a Working Bottle Jack - You can see it on our INFO Server HERE. | ||
SEALS | SEALS | ||
| − | The original hydraulic seals were primarily LEATHER and ROPE PACKING. Today, a hundred years later, leather still is being used but has mostly given way to poly-urethane and neoprene. World War II brought about wide spread acceptance of neoprene O-RINGS as an effective yet inexpensive seal and they remain with us today, along with their slightly more | + | The original hydraulic seals were primarily LEATHER and ROPE PACKING. Today, a hundred years later, leather still is being used but has mostly given way to poly-urethane and neoprene. World War II brought about wide spread acceptance of neoprene O-RINGS as an effective yet inexpensive seal and they remain with us today, along with their slightly more efficient cousins, the QUAD RING. O-RING BACK-UP RINGS, first of leather and now commonly of plastic are popularly used to keep the round o-rings from moving around and being distorted in their usually square retaining grooves. |
CHEVRON or VEE SEALS, while arguably the best, most durable seals for hydraulic applications over the past 50 years have lost ground to POLYURETHANE U-CUPS and POLY-PACKS which in the last 20 years have proven themselves to be quite excellent seals (plus, require less machine work in the original manufacturing of the jacks). | CHEVRON or VEE SEALS, while arguably the best, most durable seals for hydraulic applications over the past 50 years have lost ground to POLYURETHANE U-CUPS and POLY-PACKS which in the last 20 years have proven themselves to be quite excellent seals (plus, require less machine work in the original manufacturing of the jacks). | ||
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Another popular question we receive is - How do I bleed my jack? Well, jacks are NOT quite like the hydraulic brake system of your car. You don't have several feet of small diameter steel tubing carrying ounces of oil all over the place, so, you don't really need to bleed them as part of routine care. | Another popular question we receive is - How do I bleed my jack? Well, jacks are NOT quite like the hydraulic brake system of your car. You don't have several feet of small diameter steel tubing carrying ounces of oil all over the place, so, you don't really need to bleed them as part of routine care. | ||
| − | If your jack is acting ' | + | If your jack is acting 'spongy' the major reason generally is that you have a BAD SEAL that is sucking air into the system or else your kids (or some bugwit neighbor) played around with it and tried jacking it upside down. Whatever the reason - Here we go: |
Jack the jack all the way up/out. Release the release and retract all the way down. Open the filler plug and you should get a little psssst. Voile'! That's IT! But MAKE SURE you open the filler plug and NOT a CHECK VALVE - This will introduce air INTO your system!!!. | Jack the jack all the way up/out. Release the release and retract all the way down. Open the filler plug and you should get a little psssst. Voile'! That's IT! But MAKE SURE you open the filler plug and NOT a CHECK VALVE - This will introduce air INTO your system!!!. | ||
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CHEATING | CHEATING | ||
| − | The lifting capacity of a jack should be an exact thing, shouldn't it? Well it is, sorta, kinda, maybe... Years ago a two ton floor jack used to weigh a lot more, it had a wider base, a bigger ram piston and appeared stronger all the way around. With the flood of import jacks beginning in the 70's things changed. It was our understanding that the imports were NOT tested in any way as to their lifting capacities whereas the American jacks were. If a U.S. made jack said it could lift 2 tons, it damn well could, and usually much more, the 2 ton rating was almost it's minimum rating. At the same time some un-named brand from Taiwan that had a 2 ton rating couldn't lift half of what the American one would - and they got away with it! There simply was NO authority to question the imports claims while the Americans were stuck with government standards all over the place - no wonder the prices were so different for a supposedly equivalent jack! In response, to stay alive the American manufacturers cut, trimmed, shortened, lightened and did about anything they could to compete resulting in a situation where just about all jacks have suffered strength-wise and are the minimal tool for the maximum rating... In | + | The lifting capacity of a jack should be an exact thing, shouldn't it? Well it is, sorta, kinda, maybe... Years ago a two ton floor jack used to weigh a lot more, it had a wider base, a bigger ram piston and appeared stronger all the way around. With the flood of import jacks beginning in the 70's things changed. It was our understanding that the imports were NOT tested in any way as to their lifting capacities whereas the American jacks were. If a U.S. made jack said it could lift 2 tons, it damn well could, and usually much more, the 2 ton rating was almost it's minimum rating. At the same time some un-named brand from Taiwan that had a 2 ton rating couldn't lift half of what the American one would - and they got away with it! There simply was NO authority to question the imports claims while the Americans were stuck with government standards all over the place - no wonder the prices were so different for a supposedly equivalent jack! In response, to stay alive the American manufacturers cut, trimmed, shortened, lightened and did about anything they could to compete resulting in a situation where just about all jacks have suffered strength-wise and are the minimal tool for the maximum rating... In other words DON'T TRY TO CHEAT THE RATINGS. The American and Japanese jacks WILL lift what they say they will, but NOT a whole lot more. The Chinese and Taiwanese rarely even come close! |
NEITHER A BORROWER NOR LENDER BE... | NEITHER A BORROWER NOR LENDER BE... | ||
| − | Just about half of the jacks that came into our shop for repair were accompanied by the owner's lament - "I lent it to a friend." Don't know what it is exactly but a lent jack is soon a broken jack! People not really | + | Just about half of the jacks that came into our shop for repair were accompanied by the owner's lament - "I lent it to a friend." Don't know what it is exactly but a lent jack is soon a broken jack! People not really familiar with jacks seem to think they can lift anything and when no one's looking (and it's not their property to begin with) they try lifting a corner of their 20 ton house with a 2 ton floor jack. God bless 'em, they helped put my daughter through college, but YOU might want to think twice before you lend your jack. Our best advice is a little white lie - tell them you'd be happy to but 'it's not working right', you 'don't want to chance it...' Then tell them that you think the guy down the street with the old Mustang has one. As much as you'd like to - DON'T LEND OUT YOUR JACK! |
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