Does anybody know how to repair a hydraulic jack?

[aclwalker 3]

My dad has a substantial hydraulic jack which gradually sinks over time. It's reasonably new (maybe 5 years or so) and not had much use, but it no longer maintains its height. It's fine for jacking a car up but over a period of, say, 10-15 minutes it will have sagged substantially, requiring extra pumps to re-lift it.

 

Any idea how to fix? I was thinking that there's maybe a bit of grit in the valve that you turn to 'lock' it, or perhaps a seal is leaking. There is no evidence of external oil leakage, but perhaps the oil is leaking from one part to the other.

 

I have no idea where to get new seals. I'm not sure of the make. It might be Halfords own but I'm not sure. He might have got it from Costco.

 

It's quite annoying because it was an excellent jack and as I say, has had light use.

 

Also, I wonder if maybe we weren't storing it right, as it was generally stored standing vertically in its original box (simply because of space issues)but I wonder if it should have been stored flat and maybe a seal has 'dried out'?

 

Any ideas? Thanks.

 

Edit: BTW, I realise new jacks are quite cheap these days, but still, if it's an easy repair with a new o-ring or something then it's still worth it. The jack basically still works, but can't be trusted to hold anything up for any length of time (not that I ever trust a jack on its own anyway).

[Neil VR6 0]

My gut feel is that it would be prohibitively costly in terms of money and your time to repair it. In today’s throwaway society you’d probably be better off recycling it and buying another one unfortunately as it’s probably ‘maintenance free’.

 

I’m sure Machine Mart do a decent range.

 

I’ve found that if I haven’t used my foot pump for a while it benefits from a drop of good old ‘3in1’ to make the piston seal as it should. Maybe you could try that?

[Jim Bowen 1]

i have a halfords one that does the same as you explain, its says something on the front about oil/fluid and what to use, but i never topped mine up or checked any of that.

 

are they refillable or does air get in there?

[mrbeige 0]

I have similar problem with my Hellfrauds jack. It's about 5 years old, but loses the ability to lift after a period of time, especially if you pump it up quite high. I think it might be the hydraulic fluid that has leaked over time, and so is it possible to refill it with fluid?

 

[EDIT] ^^^^^ I'm not alone with dodgy Hellfrauds ones then?

[aclwalker 3]

My gut feel is that it would be prohibitively costly in terms of money and your time to repair it. In today’s throwaway society you’d probably be better off recycling it and buying another one unfortunately as it’s probably ‘maintenance free’.

 

I’m sure Machine Mart do a decent range.

 

I’ve found that if I haven’t used my foot pump for a while it benefits from a drop of good old ‘3in1’ to make the piston seal as it should. Maybe you could try that?

Yeah, it's unfortunately the way of the world these days, i.e. bin everything after a couple of years.

[aclwalker 3]

I have similar problem with my Hellfrauds jack. It's about 5 years old, but loses the ability to lift after a period of time, especially if you pump it up quite high. I think it might be the hydraulic fluid that has leaked over time, and so is it possible to refill it with fluid?

 

[EDIT] ^^^^^ I'm not alone with dodgy Hellfrauds ones then?

Yes, I think it actually is a Halfords one. It's bright yellow, as is the box. Perhaps it has leaked some fluid and we've not noticed. I know you can buy jack fluid from Halfords (£3.99 a bottle I think) so presumably these jacks are refillable. Perhaps they are bleedable too.

 

I'm not sure how much fluid is in the typical jack. If it's a very small amount then even the slightest leak could have an effect I suppose.

 

Something else for me to investigate while the economy implodes and I burn through my savings.

[mrbeige 0]

Yes, I think it actually is a Halfords one. It's bright yellow, as is the box. Perhaps it has leaked some fluid and we've not noticed. I know you can buy jack fluid from Halfords (£3.99 a bottle I think) so presumably these jacks are refillable. Perhaps they are bleedable too.

They have to little red caps over two access points, one of which is probably a bleed nipple (oo-er), but IIRC it does say not to remove them lol

[Supercharged 2]

Yeah you can buy the oil but I just chucked my Halfords Jack after 5 or 6 years and bought a new one, It was working ok but was getting creaky... It had done well for £21 so I just bought another the same, it's safety at the end of the day!

[Neil VR6 0]

it's safety at the end of the day!

 

Not that I've ever use a jack without an axle stand in place if I was going to lay under the car... :)

[blue95 0]

You can change the oil, if its a seal it can be repaired....not usually financially viable tho.

 

Under no circumstances would I ever knowingly work with a dodgey jack, it's just not worth the risk, get another one ASAP IMO.

[aclwalker 3]

it's safety at the end of the day!

 

Not that I've ever use a jack without an axle stand in place if I was going to lay under the car... :)

Yes, exactly. I only ever use a jack to lift a car and never go under unless axle stands are there. I also usually leave the jack in position so that if a stand collapsed then somebody (my dad is usually with me when working on cars) can quickly raise the car again.

 

When I replaced all my brake pipes I think I had 4 axle stands and two jacks under the car, including the scissor jack that comes with it. I've also used a bottle jack to provide localised pressure, e.g. gently raising the engine at one side for engine mount replacement.

 

I've never really used the 'wheel under' trick as I think it's overkill when you have multiple axle stands and jacks, but the wheel trick did save my grandfather's life when he was a young man and a bus jack/stand collapsed while he was under it. He got crush injuries but wasn't killed.

 

Much better to use proper stands though rather than wheels, but I guess health and safety attitudes were a lot different back then.

[aclwalker 3]

You can change the oil, if its a seal it can be repaired....not usually financially viable tho.

 

Under no circumstances would I ever knowingly work with a dodgey jack, it's just not worth the risk, get another one ASAP IMO.

Well, like I said, I never go under a car without stands. What's more, I almost never take a wheel off without a stand under it, even if I'm not going under it (e.g. for brake pad work). I would only not use a stand if I was just swapping a wheel or something quick like that.

 

I don't think there is a real safety issue with this approach, whether the jack slowly 'sags' or not to be honest.

[colinstubbs 0]

It would be crazy not to try topping up the oil level before deciding to buying a new one!

[mrbeige 0]

It would be crazy not to try topping up the oil level before deciding to buying a new one!

I'm going to try, can't hurt, plus I never go under a car without an axle stand anyway... :nono:

[VR6 0]

Viagra? :shrug:

[KipVR 1]

The oil level has nothing to do with the ram sliding back down, If you are low on oil you would just have trouble getting it to full travel. :D

It'll almost certainly be the the tap seat (the bit you turn to let the jack down) if there are no signs of oil.

If it was the piston seal you would see leaky oil because it's a single action ram (pushed from one side) and so any excess oil would leak to the outside around the ram.

 

Take it back to halfords they may offer an exchange or refurb kit you never know. :shrug:

[colinstubbs 0]

Take it back to halfords they may offer an exchange or refurb kit you never know. :shrug:

 

Don't hold your breathe though - they don't do replacement pressure gauges for their foot pumps, Arse.

[Skimask 0]

the jacks supplied now are pants! A halfords one lasted over a year before leaking. Yes you can top the oil up. Just unscrew the valve that lets the jack down. Be careful - it is a spring and ball bearing affair. Hold the jack upright with the valve assembly at the top and pour a few drops of oil into the hole and work the piston - it will suck the oil in - then add a few more drops etc. Clean the ball bearing/valve and spring and finally the slotted bolt. I found I had to keep the valve closed when finished - this was causing a leak.

My first jack lasted 20 years - now you only get a couple of years out of them.

[Jim Bowen 1]

can you use brake fluid? or does it say, do not use brake fluid? i can't remember

[aclwalker 3]

can you use brake fluid? or does it say, do not use brake fluid? i can't remember

You definitely DO NOT use brake fluid! I'm guessing one reason is that it would probably attack the seals in the jack. You must use proper jack oil.