[Healeys] Brake servo

GUY DAY grday at btinternet.com
Tue Jul 21 13:06:34 MDT 2009


The correct way to do this brake servo test is to first evacuate the vacuum 
chamber by pressing on the pedal 6 or 7 times, without the engine running. 
You should hear a slight hissing noise when you press the pedal as the 
chamber evacuates.  Keep pressing until there is no more hissing.  Finish 
the last press with a longer (5 or 6 seconds) hard press to see if the pedal 
goes down.  It shouldn't, it should remain solid.  Whilst your foot is still 
on the pedal start the engine and as the vacuum builds up the pedal should 
go down slightly underfoot.  This should happen more or less straight away 
and you may even feel the pedal moving before the engine actually fires up.
After the engine has started and the pedal has gone down slightly, lift your 
foot off the pedal for 3 or 4 seconds and the next time you press it it 
should be at its normal braking level.  Press the pedal hard enough to bend 
the steering wheel ( ! ! ) and the pedal should sink to its maximum braking 
position and stay there.  Keep pressed for 8 to 10 seconds, your foot / 
pedal should not sink any further.

If all of those conditions are met the servo has passed the UK DOT annual 
test.

Guy R Day

----- Original Message ----- 
From: "Gaagten" <gaagten at hetnet.nl>
To: <healeys at autox.team.net>
Sent: Tuesday, July 21, 2009 7:19 PM
Subject: [Healeys] Brake servo


 Dear list,
 Thanks for all the good ideas about my problem. Most of the people went for
 the solution of changing the flexible break lines.
 I ordered these items today, I will keep you informed.
 Second option was the servo unit. Also a test was recommended which I did,
 putting my foot on the brake pedal and start the engine.
 I did not notice any change in the feeling of the pedal? (It should go down
 for an inch).

 Regards,
 Ge Aagten
 BJ8 1964
 THe Netherlands


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