In 2011 I bought a set of British manufactured hydraulic ramps rated at 1350kg. from local tool company Vocor. Sadly the hydraulic rams started to leak after about a year of use. They didn't always leak, so I thought maybe vertical storage was the cause of the problem. I asked about this at the seller, but they couldn't help or think of a cause.
Some time later I found they were always leaking and, apart from making a slippery mess on the garage floor, I didn't relish the thought of one of the seals failing suddenly while lifting a car.
To find the cause of the problem I dismantled the ram and found that the seals looked old and worn. This is strange as I have not used these ramps that much and I bought the ramps only three years ago. Maybe the rams had been in storage for a long time?
I wrote an email to the manufacturer of the ramps, CJ Autos Ltd in the UK, to ask if they had spare seals available. They sent me a new set of seals free of charge, so I could replace the bad seals. I think that is very good service as of course the ramps were out of warranty by now.
Fitting these new seals was easy, so finally I have a set of useful ramps I can use safely, without making an oily mess on the floor. Of course a professional lift is much easier, but as I have limited space these ramps give a useful working height while I can store them upright against the wall to save space. They also fit in the boot of a car, so they are portable as well.