[Healeys] BN2 Brake Problem

[gradea1 at charter.net]

Bob-one troublesome word you mentioned in relation to the wheel
cylinders is "new." These must be the County Brand...spelled China. If
you did get lucky, and they are good cylinders, what about the other
three for the front? Rebuilt with Moss kits? I have seen the problem
with the seals being incorrect for the bore. For instance, on a Sprite
master, one push of the pedal stuck the seal in the rear of the casing
and never again to function. Replacement parts today are to be suspect
in an obscure issue like you are having. Sad Healey tales...Hank

	-----------------------------------------From: "Bob Spidell" 
To: "WILLIAM B LAWRENCE", "Healeys"
Cc: 
Sent: Saturday April 24 2021 6:45:43PM
Subject: Re: [Healeys] BN2 Brake Problem

 (non) progress report:

 Thinking Bill probably had the explanation, I clamped off the RF flex
line--the wheel I'd replaced the cylinder on--per Michael's suggestion
and, Voila!, a nice hard pedal. Thinking also that I hadn't expelled a
bubble, like Bill also suggested, I increased the pressure on my
pressure bleeding rig and bled all wheels again. Still, a nice hard
pedal, so I fired up my BJ8 to get it out of the garage so I could
pressure wash the undercarriage of the BN2 and take it (BJ8) for a
warm-up spin. Halfway around the 'block,' about 5 miles from home it
started running very rough so I pulled into a covid-closed restaurant
parking lot and popped the bonnet; coolant all over the passenger side
of the engine bay. It appears the gasket under the brass shut-off
valve for the heater hoses sprung a leak, so a call to AAA was in
order. After getting the BJ8 flat-bedded home I washed the 100's
underside, put on the new wheels and tires and hop in ... brake pedal
goes to the floor! Since I could get some brakes if I pumped the pedal
a couple times I took a chance on a short, abridged spin around a
smaller block--the new wheels and tires ride fantastic, and no
'scuttle shake' detected--then parked it.

 Thanks for all the suggestions, folks. I meant to try the
'hold-the-pedal-to-the-floor-with-a-board' technique, but by EOD I was
so beat I forgot. I've had trouble bleeding brakes on the BJ8, but the
BN2 has generally cooperated until now. Damned if I can explain why I
can get a good hard pedal, which proceeds to go soft from just
sitting. Good thing I love these cars.

 Bob

On 4/23/2021 9:06 PM, WILLIAM B LAWRENCE wrote:
   The problem with the double leading edge brakes on the 100s and
100-6s is that the bleeder screw is at a low point in the system so it
takes a little extra effort expel any entrained air. You probably got
a pretty good slug when you changed the wheel cylinder. Probably keep
bleeding that wheel and use various techniques until you find the one
that actually moves the air out of the bleeder.  
  Bill Lawrence  BN1 #554 
-------------------------
FROM: Healeys  on behalf of Bob Spidell via Healeys 
SENT: Saturday, April 24, 2021 3:04 AM
TO: Healeys 
SUBJECT: [Healeys] BN2 Brake Problem     Listers,

 I have a problem with my BN2's brakes that is driving (heh) me up the
 wall. Here's what I've done:

 - new shoes and cylinders in both rear wheels
 - one new cylinder in one front wheel (there's a total of 4 in the 2
 front wheels)
 - new master cylinder

 I hadn't touched the M/C, so after all the installs I just pressure
bled
 as I usually do (this has worked well on my BJ8 for decades and a
couple
 times for the BN2). At first, I got decent pedal then, after a period
of
 time I lost it; the pedal would go to the floor with only slight
 pressure (probably from the return springs). Thinking it could only
be
 the M/C, I sprung for a new TRW brand M/C but after installing it and
 bleeding I got the same results. I've put 2 full quarts of Castrol's
 finest 'synthetic' DoT4 through the system and tried vacuum bleeding
and
 old-fashioned 'pump and hold' method; same result for all methods.
I'm
 not losing fluid as far as I can tell, and the pedal will pump up a
bit
 with a half-dozen or so strokes, but will go back to the floor after
 some time.

 Any and all ideas and suggestions accepted and welcomed.

 TIA,
 Bob
 _______________________________________________


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/healeys/attachments/20210425/43577e8e/attachment.htm>