Raucous Kenwood Chef A701a

A noisy Kenwood Chef A701a gets a gearbox rebuild.

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This Chef had been sleeping quietly in a kitchen cupboard for some time before being woken up to make cake mixtures once again.  The owner had owned the mixer for many years from new and was sentimentally attached to it.  I fully sympathise, they’re great machines.  It had been used many times in the past and then packed away as new machines came and went.  Having decided that there was still a place for the A701a, it was fired up.

The owner didn’t remember it being quite as noisy and wondered if something was wrong with it.  She got in touch and brought it in to the workshop.   After listening to the mixer at varying speeds, we agreed that perhaps it was a bit noisy and that further investigation was required.

 At this stage I must confess at this repair has been on the bench for a long while..!

I think the A701 is my favourite Kenwood Chef product as it’s very elegant, beautifully proportioned and almost over-engineered.  It comes from a time where built-in obsolescence was a swear word.

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FixItWorkshop, Oct’17, Kenwood Chef, A701a,

On with the problem.  After disconnecting the gearbox by removing the drive belt, I checked the motor for general wear and tear, the brushes and speed control mechanism and I concluded that it all seemed OK and working smoothly.  The gearbox however did seem a bit noisy when turned manually, nothing hideously graunchy, but a little rough.  To be honest, it would have probably survived, but I wanted to open up the gearbox to make sure that it was as it should be.

Whilst removing the Chef’s casing around the gearbox, I’d noticed traces of grease around the joints and various power take-offs.  All models seem to do this to an extent, but this one seemed to be quite bad.  Closer inspection revealed that some of the grease had escaped out of the seal between the two halves of the gearbox casing.  Opening up the casing revealed that the grease that was left had been pushed to the corners of the space within the gearbox and that the gears were a bit dry, this was probably the root cause of the noise.  The planet wheel that drives the beater was also bone dry.

Luckily, there are plenty of suppliers who can supply rebuild kits for Kenwood Chef gearboxes, including new gears and grease.  The gears in this seemed serviceable, but it seemed very sensible to replace the lubricant with the correct 130g of Kenwood gearbox grease, which is food safe.  I used ‘Kenwood Chef Restore’, an eBay seller and the kit was a reasonable £10.99, including P&P.  The kit included the main gearbox grease, white grease for the planet gear and sealant for the gearbox casing.

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FixItWorkshop, Oct’17, Kenwood Chef A701a, repair kit from Kenwood Chef Restore, eBay.

Before replacing anything, the first job was to clean out all traces of the original grease which had gone very sticky and was contaminated with general wear.   The first pass clean involved using paper toweling, followed by water and detergent, before a final clean with brake cleaner, which removed the last few traces of grease and dirt.

With the gearbox refilled and resealed making sure the spacers were re-fitted to the correct parts, the drive belt re-fitted with just enough slack, the gears sounded much sweeter with the final parts of the casing reassembled.  One last point to note is that I used silicone sealant on the blender attachment power take-off plate in replacement to the one fitted, since the original seal was well past it (see below).

As a finishing touch, I replaced the existing machine feet which had turned to mush with replacements from Sussex Spares (eBay shop) for a very reasonable £2.70, delivered.

The Chef was now ready to prepare cake mixtures again.

Cost of new machine: £300 and up.  Cost of replacement parts: £13.69 (plus my time).

 

Dyson DC14 roller bearings and block/ bypass relief valve

This Dyson DC14 came into the workshop with a couple of problems.  The first was a lack of suction power and the second was a horrible noise from the front of the vacuum cleaner.  It got to the workshop just in time.

A bypass valve is fitted to most vacuum cleaners without a bag and is there to prevent damage if a blockage exists somewhere in the airways or the owner has neglected to empty the collection bin.  In this case, the valve seemed to be stuck open, causing suction power to be lost.

The valve on the DC14 (other Dyson models are similar) is a small device situated near the exhaust filter.  the valve itself is a clear tube with a rubber sealed cap controlled by a spring.  In normal operation, the cap seals a hole to the outside world, but if there’s a blockage, the pressure of the spring is overcome and air is allowed past the cap.

In this case, the valve was dirty and stuck.  Repair required dismantling with normal household tools (small screwdriver and pliers) and cleaning using a damp cloth.  A small squirt of silicone spray on the rubber seal ensured a smooth operation upon reassembly.

 

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FixItWorkshop April’17, Dyson DC14, repaired in the workshop

The noise was traced to the front of the vacuum cleaner.  The roller/ beaters were making a horrible noise when in use and it wouldn’t have been too long before complete failure would have occurred.

Spare roller/ beaters are readily available from Dyson directly and from many aftermarket suppliers at reasonable prices.  Since the beaters were in good condition, it seemed reasonable to have a go at a repair.  The small ball bearing races at each end of the beater are easily removed and upon inspection, both were very stiff in operation.  Fortunately, the bearings used by Dyson were of good quality and as the dust covers were easily removed, all that was required was a clean with solvent cleaner and a re-grease.  Once refitted, the roller/ beaters sounded as they should again.

Cost of a replacement Dyson vacuum cleaner, circa £250, cost of repair £1 (bit of cleaner, grease, silicone spray.

Dyson DC33 repaired in the workshop

Conked out Dyson DC33

This Dyson presented with a pretty terminal case of ‘no go’.  The owner had run this relatively new machine in to the ground with little maintenance so it was little wonder what happened next.

Whilst in use, the machine spectacularly went bang and tripped the main fuse board of the house.  The noise and following smell was quite something I was told.

The owner had nearly rushed out and bought a new machine and was budgeting between £300 and £400 for a replacement.

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FixItWorkshop, Worthing, Feb’17. Dyson DC33 motor replaced

I was glad I could help since I was fairly certain I knew what the problem was without seeing it.  After giving the cable, switches and casing a visual inspection, it was time to delve deeper.  The filters were in poor condition and the general smell of it indicated that overheating had been an issue, probably leading to premature wear on the motor.

With the motor out, the true extent of the damage became apparent.  Both motor bushes had worn away to nothing and part of the brush holder had broken up inside the motor, probably while it was running, causing the noise.

I suspect that the owner had ignored the warning signs of burning smells and occasional cutting out (as the thermal overload circuitry performed its fail-safe role).

Being only a few years old, the owner had a couple of options; either replacing the faulty part with a genuine Dyson replacement (a very reasonable £40) or pattern motor kit with filter pack for under £25.  The owner chose the latter on the basis of the machine’s age and the fact that both filters in the machine were also ruined.

The job took an hour, including testing before the machine was back performing its cleaning duties once more.

A note to all vacuum cleaner owners (that don’t take bags):  Keep your filters cleaned every couple of months or so.  Your machine will last much longer if you do.