Author Topic: DC24 brush bar operation. (Read 7601 times)

cleanman27 · « **on:** May 02, 2013, 11:26:42 am »

On my Dc24 the brush bar will operate correctly for 99% of the time. If the hose is used, handle upright, afterwards the brush bar will sometimes NOT operate unless the brush switch, by the power switch is operated. Yesterday the brush bar started OK but continually cut out, and had to be restarted again with its switch by the power switch.

Now I've de-fluffed the brush bar , the overload switch is pressed in and the micro switch is OK at the base. However I thought that the brush bar switch could be used to switch OFF the brush bar, which mine will not do, provided the brush bar was operating when it was pressed. Dyson engineer changed this switch for a new one a couple of years ago but if my thoughts on how it should switch OFF the bar as well as On are correct it would appear I need to replace it.

Do you agree?

eyemdee · « **Reply #1 on:** May 06, 2013, 10:30:29 pm »

Yes, sounds most likely to be the main brushbar switch at fault but it could also be the other micro switch which disconnects the brushbar when upright. I presume these are wired in series so either one can open the circuit and both have to be closed for the brushbar to operate. I would be looking to test both switches for intermittent operation.

cleanman27 · « **Reply #2 on:** May 07, 2013, 06:00:32 pm »

Thanks for that, I pretty sure it's the main brush switch as when it working you can turn off/on the brush head by tilting the handle. Pressing the main brush switch when it fails regain operation. So I've ordered two switches for the handle area, the main ON/OFF and the Brush ON/OFF. As they are so cheap from man-vac it seems silly not to change both once the area is disassembled. They seem a pretty ropey switch and to be honest I find the main ON/OFF switch to be a bit hit and miss with its OFF action. Will report when changed.

cleanman27 · « **Reply #3 on:** May 09, 2013, 12:43:52 pm »

OK switches arrived and I took off the switch assembly from the handle.

Continuity check on the original switches showed that they were both OK, strange.
Fitted new switches and found that the machine would not lock ON, removed assembly again and found that the switch I fitted in the ON/OFF position needed to go down further than the other to operate, only a mm difference but enough to prevent it operating with the mechanical limit on the ON/OFF button. swopped them over, reassembled.
Runs, but now unable to turn OFF the brush bar from handle. Take apart again. Investigate the operating system, switch is OK and if the unit is assembled without the brush bar button all works OK. Looked again at the interconnect between the ON/OFF and the brush bar switch and found that the lower end of the brush bar switch had a small lip on it, and the handle cover moulding wasn't square, small amount of filing and all now pass by each other OK. Quick spray with silicon lube. Reassemble again and this time ensure that the tongue on the interconnect slips into the cam in handle and plug in.

Now ON/OFF switch stays On and the brush bar is controllable by the handle switch. Can be turned OFF and ON independent of the main switch. If brush is OFF when main switch turned OFF, it will be switched ON again when mains is switched ON. Now operates as it should.

Worth the £6 I spent