Rebuild a floor jack or leave it be?

Bminder · Oct 30, 2011

I just picked up a used Napa 791-6420 floor jack for $30. They told me when I bought it that it jacked fine but leaked down a little. I found the manual online and popped off the fill button and topped it off, then bled it. It still leaks down a little, so I'm wondering if it's worth getting the rebuild kit from Napa. It's about $35.
How hard it is to rebuild, and is it worth it?

Hiball · Oct 30, 2011

Bminder said:
I just picked up a used Napa 791-6420 floor jack for $30. They told me when I bought it that it jacked fine but leaked down a little. I found the manual online and popped off the fill button and topped it off, then bled it. It still leaks down a little, so I'm wondering if it's worth getting the rebuild kit from Napa. It's about $35.
How hard it is to rebuild, and is it worth it?

Rebuild it, $35 bucks is a Fair Price for the Seal kit. I suspect the Main Ram seal is the culprit. BTW.. If you do decide to rebuild it, Dont venture into the valves..

Bminder · Oct 31, 2011

Thanks Hiball, I've done some searches and read your posts about leaving the valves alone

The kit Napa actually quoted $24 plus $10 for shipping.
Is it very hard to do?

Hiball · Oct 31, 2011

Bminder said:
Thanks Hiball, I've done some searches and read your posts about leaving the valves alone
The kit Napa actually quoted $24 plus $10 for shipping.
Is it very hard to do?

No, You will need some general hand tools, A vise to remove the tank nut and a little time in the Shop. Im easy to get ahold of and always willing to help...

Bminder · Oct 31, 2011

I've read different things about this jack. Is it Chinese built or American?
The online manual I found shows a breather valve on top, but this one just has a rubber plug.
It was from a Goodyear tire store that went out of business.

Hiball · Oct 31, 2011

Bminder said:
I've read different things about this jack. Is it Chinese built or American?
The online manual I found shows a breather valve on top, but this one just has a rubber plug.
It was from a Goodyear tire store that went out of business.

Its a Import (3.5 tons), From the factory it had a Breather.

Bminder · Oct 31, 2011

When I popped the plug off it didn't look like there were any threads in the hole.
I topped it off with hydralic jack fluid, then did what the manual said to bleed it: Pump the jack to full height then let it down and repeat that a couple times.
But I've seen other info that to bleed the jack you open the release valve and pump the handle 20 times.
What's the best way to bleed it?

Hiball · Oct 31, 2011

Bminder said:
When I popped the plug off it didn't look like there were any threads in the hole.
I topped it off with hydralic jack fluid, then did what the manual said to bleed it: Pump the jack to full height then let it down and repeat that a couple times.
But I've seen other info that to bleed the jack you open the release valve and pump the handle 20 times.
What's the best way to bleed it?

Both will do it, The reason you pump it while in the Release position is to fill the Valves with oil, Its always a good idea to cycle the jack a few times as long as there is plenty of oil in the resevoir. If the Oil is low it will only ingest air back into the system.

sjdon67 · Nov 4, 2011

Not a bad price for a rebuild kit. Is the jack made in USA?

MalibuLX3 · Nov 4, 2011

I'm not sure if you ordered it yet or not, but did you know Hiball actually sells hydraulic jack rebuild kits??? If you're going to wait for it to ship from Napa, you might as well buy it from Hiball...probably better quality parts too!

Hiball · Nov 4, 2011

sjdon67 said:
Not a bad price for a rebuild kit. Is the jack made in USA?

No the Jack is a Import

MalibuLX3 said:
I'm not sure if you ordered it yet or not, but did you know Hiball actually sells hydraulic jack rebuild kits??? If you're going to wait for it to ship from Napa, you might as well buy it from Hiball...probably better quality parts too!

I dont sell "Kits" for alot of the Import jacks, With that said i can supply members with all the Individual parts as long as sizes are given. In this sitsuation it will be easier for the OP to get the kit from Napa, Im not always the cheapest around but i have no problem pushing members in the Cheapest/Easiest Direction. I apreciate the Compliment though... :thumbup:

Aeromech · Dec 25, 2011

HiBall,
I was just given a Napa 791-6420 and it takes me 35 pumps to reach full height. I'm guessing I need to rebuild the cylinder or have it done by a professional. I have already tried filling it and now I'm seeing fluid on the floor. Please advise.

My new Arcan next to the Napa

Hiball · Dec 25, 2011

Yes.. 35 Pumps is Excessive, It could be a Pump Piston seal or the Main Ram Cup. Will it lift a Load? Where is it Leaking?

hossdoc · Jun 27, 2012

Hiball,
I am currently in the rebuilding process of this very jack. I have already replaced the pieces in the valve body. Now, why exactly should I have NOT done that?

Hiball · Jun 27, 2012

hossdoc said:
Hiball,
I am currently in the rebuilding process of this very jack. I have already replaced the pieces in the valve body. Now, why exactly should I have NOT done that?

Nothing Wrong with Replacing the Valve Parts, The only problem is getting the High/Low/Overload Valve adjustments back to where the Jack functions Properly. I always recommend that people check the OEM settings of these valves "Prior" to Tearing it down that way when you dont have a lot of trial and error. The Most important Valve to check is the Overload, This cant be set properly with a test station and its a Safety feature to make sure the Seal's Max PSI isnt exceeded by Overloading the jack.

hossdoc · Jun 27, 2012

Hiball,
I would like to apologize for my lack of anatomical knowledge with regard to my floor jack. Do you have an exploded view of this cylinder? The owner's manual does not have one.
I removed the large plug and replaced the small then the large BB. The smaller plug housed a smaller plug and a spring with a bullet shaped valve at the end. You are correct in assuming that I did NOT count how many turns it took to get the smaller plug loose. How should I proceed?
Also the kit did not include an O-ring the obvious size for the handle's plunger. Additionally, the O-ring for the base of the inner screw in pipe appears different than the one I removed. I was sent a rubber O-ring and a plastic one that fit this location. I am therefore having some trouble getting this back together correctly.
I am sorry if this is not the correct venue for these questions. PM me if it would be more appropriate.

Hiball · Jun 27, 2012

hossdoc said:
Hiball,
I would like to apologize for my lack of anatomical knowledge with regard to my floor jack. Do you have an exploded view of this cylinder? The owner's manual does not have one.
I removed the large plug and replaced the small then the large BB. The smaller plug housed a smaller plug and a spring with a bullet shaped valve at the end. You are correct in assuming that I did NOT count how many turns it took to get the smaller plug loose. How should I proceed?
Also the kit did not include an O-ring the obvious size for the handle's plunger. Additionally, the O-ring for the base of the inner screw in pipe appears different than the one I removed. I was sent a rubber O-ring and a plastic one that fit this location. I am therefore having some trouble getting this back together correctly.
I am sorry if this is not the correct venue for these questions. PM me if it would be more appropriate.

Are you referencing the Napa Jack? Where did you get your Kit from? I would call them and let them know you are missing some parts or have incorrect parts.

Does your jack have 4 valves on top of the Unit or 3? I believe this Magic lift from Omega (Shinn Fu) should correspond to the 4 valve version that Napa sells.

http://www.shinnfuamerica.com/Temp/2502.PDF

If yours doesnt match up, Post up some pictures.

hossdoc · Jun 27, 2012

Hiball,
Thanks for the exploded. It is not correct however. Mine only has 2 valves. I have included pics.

I ordered the kit from my local NAPA where I purchased the jack some time ago. The package reads RS35SK. Is this even the correct kit for MY jack?

Hiball · Jun 27, 2012

hossdoc said:
Hiball,
Thanks for the exploded. It is not correct however. Mine only has 2 valves. I have included pics.

I ordered the kit from my local NAPA where I purchased the jack some time ago. The package reads RS35SK. Is this even the correct kit for MY jack?

Probably Not.. Im no expert on Napa Part numbers but i suspect you have alot of extra pieces left over. Your jack is just a standard Lift, No Quick lift etc....

BLAH.. at that Shell/Oring Main Ram Seal.. You need to upgrade to a UCUP.

Btw.. Your jack only has 1 valve that has a Adjustment on it <--- Overload. The Other valve is what i call the Working valve.

hossdoc · Jun 27, 2012

Hiball,
Thanks for the advice. Where do I source this part in Fort Worth TX?

I have several small back up rings and matching O-rings.

I still need the correct one-piece O-ring for the base of the center pipe (items F and G on the diagram you sent) and the O-ring for the pump plunger.

Do you have an exploded for MY jack?

Hiball · Jun 27, 2012

hossdoc said:
Hiball,
Thanks for the advice. Where do I source this part in Fort Worth TX?

I have several small back up rings and matching O-rings.

I still need the correct one-piece O-ring for the base of the center pipe (items F and G on the diagram you sent) and the O-ring for the pump plunger.

Do you have an exploded for MY jack?

I keep most of those parts in stock.. I just need some Measurements.

hossdoc · Jun 27, 2012

Hiball,
What is the best way to contact you directly? and when?

Hiball · Jun 27, 2012

hossdoc said:
Hiball,
What is the best way to contact you directly? and when?

PM Sent..

Rebuild a floor jack or leave it be?

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