[Healeys] Brakes

Bob Spidell bspidell at comcast.net
Fri Jun 12 10:14:39 MDT 2020


If a significant amount of brake fluid is leaking into the servo you 
will get white smoke out of the tailpipes (under most running 
conditions). This is because the engine will suck fluid into the intake 
manifold through the vacuum hose. The most likely cause of this is the 
'gland' seal; which seals the vacuum piston--the large canister on the 
servo--from the servo's hydraulics (it has two pistons; one is activated 
by pedal pressure to gate air at ambient pressure into the canister to 
assist a second 'master' cylinder, which powers the slave cyls).

You can rebuild the servo yourself; I've done it once successfully, 
others report 50-50 success. I've not heard overwhelming stories of 
success with aftermarket (Lockheed, or an Australian equivalent) 
replacements, but some like them. They aren't apparently, a 'drop in' 
replacement without some fiddling, and hearsay says they're not as 
effective as the Girling (putting my Nomex suit on). The hydraulic 
section of the servos is not much different from ordinary brake 
cylinders. The shop manual has an excellent explanation of the theory 
and workings of the servos; it took me several reads and some cogitating 
to grok it all, but they are pretty ingenious.

If you're not getting any white smoke, your guess is as good as mine; I 
have the same problem--although I haven't pulled the drums to check the 
rear slave cylinders (fronts are not leaking)--but since I had bled them 
before the problem occurred I'm thinking I screwed the pooch somehow on 
the bleed.

Bob


On 6/12/2020 8:46 AM, Fred Wescoe wrote:
> I am having issues with the brakes on my 66 BJ8.  I am new to this BJ8 
> with boosted brakes, but I have owned a BJ7 for many years.  I don't 
> find any clues in the shop manual or in Norm Nock's tech talk manual.
>
> When I press the brake pedal, it slowly goes to the floor. I am losing 
> hydraulic fluid in the reservoir but there are no apparent leaks that 
> I can see.  There are no fluid spots on the garage floor at each wheel 
> and no evidence of brake fluid on the wire wheels which would indicate 
> a leak.  I have pulled each wheel and I do not see brake fluid anywhere.
>
> Is it possible that the fluid is leaking into the brake booster?  How 
> am I able to check that out?  If this is the case, can the booster be 
> repaired by me or someone else, if so, who.  If fluid is leaking into 
> the booster, is it  better to simply replace the booster and who is a 
> good source?
>
> Something always happens before what promises to be a great sunny weekend.
>
> Thanks for any help,
>
> Fred
>
>
>



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