Tuesday, 18 January 2011


Here's a reassuring sight that 270 KTA's driver won't have seen for years, perhaps even decades.

It's a gauge showing a full tank of vacuum.

After weeks of isolating pipes in search of a likely hairline hole, followed by the fiddly removal of the exhauster (the bit that generates a suction which ought to evacuate the tank), followed by the refitting of another... and another... and... etc., I've finally managed to establish why we've been struggling to build up vacuum to operate the brakes.

The answer was a simple spring and ball bearing, missing from inside 270 KTA's original exhauster, which acts as a crucial non-return valve to prevent suction being 'wasted' through the pipe which is supposed to drain off excess oil to the engine. Essentially, the thing was sucking through its arse and not through its mouth.

The valve was missing from one of the replacement exhausters too, and back to front in the other, so it's no wonder it took a while to trace.

One thing's for sure: 270 KTA can't have built up a safe vacuum for as long as the valve has been missing, a fact worryingly confirmed by this photo of her in use with previous owners, showing the gauge barely reaching the halfway point. I'm glad I wasn't on board...

Now mended, the brakes not only work pronto, but vacuum replenishes so quickly after each operation it would be impossible for the needle to crawl this low with the engine running.

With the vacuum issue resolved, I started work this weekend on stripping-down the front nearside brakes. Other than two seized adjusters, everything seems to be working, if badly in need of cleaning and adjusting.

The brake drums, apparently well-silvered when viewed through the wheel, speak of quite a different maintenance philosophy to my own. Look closely with the wheel off, and you'll see that a paintbrush had been poked through the holes just to cover the visible bits...

Inside, meanwhile, the brakes themselves are long overdue some 'silver service'...

Ironically, the drums should be green, not sliver, and will be when they go back - hopefully with original-style wheels to boot.

As I write, I'm about to revive an old tradition of the Sheppard household. The kitchen sink has been primed to receive its first bus part for cleaning - the centre hub cap which, instead of green, will emerge in original polished aluminium condition. Unlike the sink, I suspect...

It's a long road, but we are making progress.

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