M/c Jack leaks by

[N0tac0p]

I have the typical M/C jack (Sears), and as i have been working on my bike for the last two weeks i have had an opportunity to note that the hydraulics must leak by.  I say that as i went to pump it up with the foot pedal.....no resistantce for about 5 pumps and then it got more solid.  so i am assumming, the bike is sitting on the safety bars.  has anyone ever rebuilt the hydraulics on their Jack?  advice?

[hubcapsc]

I just posted this picture on another thread where a member's bike
fell off the jack:



The board in the jack scissors keep the jack from deflating...

I know a guy who tried to work up a jack fixing business (apparently nobody
wants to pay to fix a $10 Chinese jack, though)... I asked him about it and
he said they were easy to fix, take them apart and put in a new Oring...
I never tried that, but I did try a bleeding procedure that was in the jack's
manual, or maybe I googled it... didn't change anything... anywho... the board works for me...

When I need to raise the bike off the board, the jack responds right away, as if
with help from the board it doesn't leak down... (but it sure would without
the board)...

-Mike

[PAVALKER]

While that board is an excellent secondary safety.... We should try to remember to actually lower the jack to the installed safety stops (they are built into the jack at graduated heights), and relieve the pressure of the bike on the hydraulic jack.  That should help save the seals, hopefully prolong the life of the hydraulic jack, and  keep the bike in the upright position off its side on the floor.


Oh and don't forget to slide that rear axle in before ya jack the bike up..... 

[Bone]

My jack is a Sears and looks just like the one in the picture. Bought it in "05" when I bought my Valk. I posted about my jack starting to slowly leak down when 2 or 3 years old. Make sure you use the metal stops.
Looking through the owners handbook it says to change the oil once a year    I didn't remember reading that when I bought the jack. Changed the oil and burped the air out and no more leak-down. Now that I write this I checked my garage note pad and I didn't change the oil last year forgot. I'm in a cold climate the bike sits on the jack 3-4 months some winters I was lucky last winter. It's easier than rebuilding but mine didn't leak oil just pressure to support weight.

[hubcapsc]

While that board is an excellent secondary safety.... We should try to remember to actually lower the jack to the installed safety stops

The stops seem failsafe. I use the board because I like to jack the bike to where I want it
to be, not where the stops are...

Oh and don't forget to slide that rear axle in before ya jack the bike up..... 

D'OH!

-Mike 

[N0tac0p]

I alwayas release to the stops and then apply ~ one foot pump to have the hack share the load, and yes it DOES NOT "leak" oil, i believe it is "by-passing"  due to the weight.  so when i get her off, ill change the oil

[Bone]

I found Hydraulic / Jack oil at AutoZone so I haven't looked at other stores.

[BF]

Yes, you're supposed to change the fluid in the bottle jack once a year. 

With this....

[old2soon]

The stops are there to alleviate the pressure on the jack. The jack is designed to get object/vehicle to desired height and then a solid mechanical device-jack stands stops built into the lift-to hold object/vehicle at raised height. I have hydraulic jacks screw jacks and the old one click at a time in the shop some where. I DO NOT work on the object/vehicle UNTIL it is on the jack stands or the safety stops on the M/C lift. The hydraulic portion of the lift is not designed to hold object/vehicle long term-safety stops and jack stands are designed to hold object/vehicle long term. RIDE SAFE.

[N0tac0p]

exactly

[0leman]

The stops are there to alleviate the pressure on the jack. The jack is designed to get object/vehicle to desired height and then a solid mechanical device-jack stands stops built into the lift-to hold object/vehicle at raised height. I have hydraulic jacks screw jacks and the old one click at a time in the shop some where. I DO NOT work on the object/vehicle UNTIL it is on the jack stands or the safety stops on the M/C lift. The hydraulic portion of the lift is not designed to hold object/vehicle long term-safety stops and jack stands are designed to hold object/vehicle long term. RIDE SAFE.

I agree with you.   I use my MC jack to get to the desired height, then put  manual Jack Stands under the crash bars before I do anything.  If the hydraulic's in the MC jack looses pressure the jack stands will keep the bike upright.   I have had the MC Jack holding my Valk for several weeks, without any problems with the hydraulic jack loosing pressure.  I bought the MC jack in 2006.  I gets used maybe two times a year.