"I bought this product to complete a fuel filter change on the car, I needed to suck fuel through the new filter to prevent an airlock whilst reconnecting the hoses.
I was sceptical about the performance of the product after reading the reviews of others, but I found it to be exactly what I needed, I was able to draw fuel through relatively easily by squeezing the bulb until there were no bubbles showing in the input hose. I have some advice for using this product:
The no-return valve does seem weak (especially when drawing air through) and it will let fuel go backwards if you stop pumping. For this reason I trimmed the hose to 15cm from the filter to the pump but retained the longer hose from the pump to the container I was using to collect the fuel. Once the fuel was pulled through to the pump, it became much easier to achieve a good flow - it helped to press the pump firmly with my full hand.
I used the pump horizontally to minimise the effect of gravity (instructions say to use vertically) and I can see why you might find it difficult to draw fuel vertically along the full length of the hose from a fuel tank. But, overall I was happy with the performance as I was able to complete the job!"
"Used this when I do my pluming, works well, I have had some issues with it stopping working but I think this is due to scale or debris being sucked in to it, I managed to get it back working with little effort, shame it doesn't have a filter or similar to reduce this happening."
"This tool doesn't do what it is supposed to do. I bought it to get the diesel out from my car before it goes to the scrapyard. The pump is not strong enough to lift the fuel. With a much bigger pump and a longer hose it could work but this item is useless, couldn't get any fuel out. Don't buy it!"
"This item is useless, it does not do what it is supposed to do as the pump is nowhere near strong enough to create any kind of vacum from one container to another. After two hours I had managed about 0.5 litre to be transferrred and evetually gave up. Very frustrating to see the fuel come into sight then dissapear back down the tube again due to the ineffectiveness of the syphon pump. I even tried it on a bucket of water so I could see what was going on and this failed to work either. Comes with no instructions at all for use. Eventually I wrapped it on a bag and threw it in the bin."