Originally Posted by
sparky
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the thing to look at is the pump, I've worked on hp pumps, so have an understanding of them better than a lot of people. In the smaller Karchers, and a lot of other cheaper makes the pistons are made of nylon, and this is for 2 reasons, 1 the cost, and 2 the length of time they are designed to last.
In a domestic situation any tool is expected to do a limited amount of work over the guarantee period, I remember Black and Decker used to reckon that in the hands of a DIY'er one of their drills would do no more than 6 hours work over a year, the warranty period, there were certain parts in the machine that they knew would only fail after 1o hours use, so if you took the drill in under warranty and one of these parts had failed, they'd deem it to have been used in a non DIY situation and therefore voided the warranty, it was a con basically, especially when you considered that a lot of people had sawing and sanding attachments for their drills.
It's the same with the nylon piston in a pressure washer, they know how long they will last before they fail, they actually melt!, effectively ruining the pump. Now they know that these will only fail in 2 situations, 1, running the machine dry, (remember you should always pull water through the lance before switching on) or 2, the machine has done more than the calculated number of hours during the warranty period, it's ridiculous how they calculate this, believe me.
The best advice I can give to anyone looking to buy a pressure washer is to find out if it's a metal pump, or a plastic one, yes, they're even making some units now with fully plastic pumps!
If it's a metal pump with metal pistons then the O rings can be replaced fairly easily and cheaply, you can do them yourselves. I have a number of Kango breakers, they are all over 30 years old, they don't make them any more, the only thing that ever fails is the piston seals, meaning they don't hammer, a seal kit is about £40 online, I found out the size of them, basically an imperial O ring and bought a box full for less than a tenner, now I can repair these machines at my leisure. it really is that easy, a lot of stuff uses common parts, you just have to identify them, I remember a bearing failing in the washing machine, a bearing from the supplier was about £50, a bearing from the firm who supplied the manufacturer was about a fiver. hope this saves some people a few quid.