Clean It Up
UK General Cleaning Forum => General Cleaning Forum => Topic started by: Ged on June 17, 2006, 06:58:56 am
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Dear Doctor
First, thanks for your very informative posts on the forum. i was reading your comments about the running of the pressure washer in bi -pass. i was told when i bought my machine two years ago to avoid this at all costs as it will shorten the life of the unloader valve. i work off a trailer so often a long way forom the machine so tend to run in bi pass quite a lot the unloader valve is still working fine but tends to leak very slightly from time to time.
are the valves easy to replace and if so how do you do it (my machine is 13 hp honda from Tech Clean) as i would rather replace the unloader than constantly worry about running in bi pass.
Regards
Ged
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Hi Ged,
Thanks for that glad to see someone appreciates me, even if I can't spell it lol!
It's not the engine type but the pump that controls cost of underloader. I would imagine you probably have an Interpump ww965 or similar, if the underloader vah the tall black pressure adjusting numpty) is outside of the pump cylinder head by that I mean connected by a tube or fitting usually 3/8 inch BSP (22mm spanner ) nuts they are about £31 + vear and tear (VAT) but they do need setting up. Don't fall for the "what machine have you? we will just fit the right spring" touch. Get a dedicated one for your machine.
To my dismay some of the newer pumps being sold have a built in underloader that has a built in internal by pass, the biggest draw back in my opinion is, if like you, you have to change the underloader is you have to change the WHOLE cylinder head complete, very costly, probably £280 all in.
As to the external by-pass causing premature failure of u/loader, rubbish the u/loader goes into by-pass, stays there or drops out of by-pass exactly the same weather internal or external, as I said before it's the heat build up in only a couple of mins that does damage in an internal arrangement, if you have this one you must not let machine run with triggers OFF (in by-pass) for more than 5 mins MAX
Wear on underloader showing as leaking around the shaft the numpty is on is caused by exsessive by-passing then going back into pressure mode,then by-passing again. This is the symptom of an high pressure leak anywhere from outlet on underloader, to the small shaft in the trigger guns, including all the h/p pipe joins/couplers (quick release connects are prone to this as they are underrated for 250 bar m/c. Ahy leaks here whilst m/c running full revs and triggers OFF will leak off the trapped line pressure that causes the underloader to by-pass, reulting in the underloader popping up and down (in and out of by-pass) all this EXTRA movement contributes to wear. So fix any h/pressure leaks!
And don't put any oil or grease on triggers, threads with rubber o rings in them or the underloader as oil rots the seals, use a silicone spray or silicone grease