Jeff,
When I rebuilt my '77, I went all though the brakes and the clutch system.
Before installing the rebuilt calipers and the new rear wheel cylinders I
flushed the system and then put in silicon fluid. Be sure to flush the system
as the silicon fluid is not compatible with the older DOT 3 or 4. I flushed
mine with the silicone fluid, others have recommended isopropyl alcohol, which
is definitely a better way to go (less costly and less messy).
FYI - You should be able to get the silicon fluid at your local discount auto
part stores for about 1/3 to 1/2 of what Vicky Brit charges. I got mine at
'Jocko's', $10 a quart.
Thanks,
Paul Mostrom
'77 Spitfire 1500
'80 Ford F-100 (Triumph Support Vehicle)
'Black holes, where God divided by zero......'
-----Original Message-----
From: Jeff McNeal [mailto:jmcneal@ohms.com]
Sent: Thursday, January 06, 2000 12:46 PM
To: Spitfire List
Subject: Switching to DOT 5
Hi all... I currently have no brakes because there's a leak somewhere in
the hydraulics. The previous owner was using standard (I'm assuming DOT 3)
brake fluid in the reservoir, although he used only Catrol Girling in the
clutch (thank goodness!). I don't know if natural rubber is used in the
brake and wheel cylinders, but I'm guessing they do and that the use of DOT
3 smoked the rubber seals.
I'm replacing the rear wheel cylinders with brand new ones from Spitbits and
also ordered a rebuild kit for the master cylinder and another rebuit kit
for the front caliper pistons. I've decided that this might be an excellent
time to convert to DOT 5 silicon, so I've ordered a quart of that stuff from
Victoria British.
My questions are as follows:
Is my assumption that using DOT 3 in the brakes thereby destroying the seals
valid? Or do the brakes not use natural rubber seals anymore? Nigel was
unable to tell me whether or not the specifications for the seals have
changed over the years, but I suspect that the original specs still apply.
Will a quart of fluid be enough to bleed the system properly? I sure hope
so. That silicon stuff is expensive!!
Is there any reason I should NOT go with DOT 5 silicon and simply stay with
DOT 4 Castrol Girling? I understand that the silicon fluid might be a
smarter bet for someone like me who will not be using the car as a daily
driver.
Thanks!
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