Jeff,
There's been a few replies about needing to completely flush the old brake fluid
out, so I won't repeat that.
You said you won't use the car as a daily driver. I seem to recall that DOT5
might not be such a good idea for cars that aren't used reguarly.
The problem is that DOT5 doesn't absorb any water. Normally, this would be a
good thing in a brake fluid, and this is one of the reasons people switch to
DOT5 (apart from not wanting to corrode their paint). But if the fluid doesn't
absorb water, any water which gets into the brake system will just sit in the
brake pipes not moving, and will cause localised rusting of the pipes, from the
inside out. This isn't a problem if you drive the car regularly, because the
water will move around as you drive, and rust won't get a chance to set in, but
if the car's sitting for extended periods it may be an issue.
I'll leave this one for the list to debate - no doubt you'll hear from some
people who leave DOT5 in their car for 6 months of the year and have never had
any problems.....
Dean
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Date: Thu, 6 Jan 2000 10:45:57 -0800
From: "Jeff McNeal" <jmcneal@ohms.com>
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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