triumphs
[Top] [All Lists]

Re: Problems bleeding Spitfire brakes (long update)

To: triumphs@Autox.Team.Net
Subject: Re: Problems bleeding Spitfire brakes (long update)
From: Eric Kieboom <ekieboom@xs4all.nl>
Date: Fri, 02 May 1997 20:56:30 -0100
Thanks for all your replies so far! I've got some things to look into.

About an hour ago, we were really fed up and I said, while opening the left
rear bleed nipple: "just pump the pedal!". My father pumped it five times
and I closed the nipple. Hardly any tiny bubbles. "Now try it..." The pedal
was firm - Great!

I took the car out and drove a few miles, doing some normal braking, which
got noticeably worse :-(. When I returned I could almost push the pedal to
the floor and braking was marginal. The discs were hot, the drums warm, and
the fluid in the reservoir had dropped very slightly. I left the car for a
few minutes and tried again: firm pedal. So I drove it for about ten miles
and the pedal became all soft again... AAAARRRGGHHH!!!!

*Now* what?

===
John Matthews <matthews@sj.bigger.net> wrote:

>This is really common. If you have one of those double resivoirs make
>sure you fill the rear chamber.

We made sure of that and topped it up after every ten pedal strokes...

>Also try adjusting the rear adjusters, these can make the whole system feel
>spongier.

Adjusted them *just* right, makes no difference.

>I don't know how stiff
>the pedal is supposed to be, but something tells me it's not very......

I know it can be quite stiff if properly bled. Not up to Citroen standards,
of course, but still.

====
David M Brock <dmbrock@julian.uwo.ca> wrote:

>Sounds like you might have the seal in the master cylinder in backwards.

I thought about that, although I'm sure put the new seals in exactly the
same way as the old ones came out, like this (the slashes and backslashes
depict the way the lips on the seals are pointing):

          \|________|/            \|_________\|
\\\\\\\\\=  ________  >\\\\\\\\\\\= _________ [
          /|        |\            /|         /|

 rear         rear        front       front
spring       plunger      spring     plunger

>Are you quite sure that all other nipples are sealed tight?  You could be
>sucking in some air from a badly sealed or crossthreaded nipple on another
>of the wheels.

Quite sure. I'm very careful not to open them too wide (so as not to draw in
air through the thread) and close them firmly after bleeding. Got all the
nipple threads well covered in copper grease. Positively _no_ leaks.

>The other thing might be that you have one of those reservoirs (like mine)
>that has a very small opening to the rear system (dual system) and you're
>not actually filling the right one up?  Don't scoff at me- I made this
>error, and couldn't understand where the air was coming from.

I think I don't get what you mean: my '77 Spit 1500 has a reservoir that's
divided into two parts. The front part is readily accessible throught the
filler cap and feeds the rear brakes - the rear part is connected to the
front by some vertical slits and feeds the front brakes. I cannot properly
fill the front part of the reservoir without also filling the rear part.

===
"PAUL LOGUE" <GPAULOGUE@msn.com> wrote (four times ;-):

>Try topping reservoir by pumping fluid from the bleed nipples up to the 
>reservoir. Use a plastic line attached to a pumper can.

Hmmm, that's an interesting approach. I might try that sometime, if the
reservoir is empty ;-)
On the other hand: Andy Mace seems to have a good reason to dislike it... :-|

===
Tom Howard <thoward@sdcoe.k12.ca.us> wrote:

>Here is a test you can do.
>
>Close up all the bleeding screws.    Clean everything off so that there is
>no trace of brake fluid anywhere.    Now,  get in and press hard on the
>pedel.    Hold this pressure for a couple of minutes.    If there is a leak
>anywhere in the pressure side of the system you will get some brake fluid
>showing up.

Did that - no leak.

>If you can't find any leak then you should look at the vacuume side of the
>system.  That is when you release the brake pedel the system sucks fluid
>into the master cylindar from the tank.   There could be a problem there.

What kind of problem could that be and how could I find out if that's it?

>Also, when holding the pedel down for those minutes it should not move.
>This is it must not creep down as you push.   If it does that is another
>indication of a leak or a "bad" master cylindar.

Ahh, I think we might be on to something here... The pedal always was a bit
of a 'creeper' and it still is, even after overhaul. I am beginning to
distrust that master cylinder (and I don't like the price of a replacement -
ugh!).

What I still don't understand, though, is how can it be nice and firm at the
start of a trip and very soft after driving a couple of miles and braking a
few times?

Eric Kieboom
The Netherlands
   ____    _       __ ___     __
  / __/___(_)___  / //_(_)__ / /  ___  ___  __ _
 / _// __/ / __/ / ,< / / -_) _ \/ _ \/ _ \/  ' \
/___/_/ /_/\__/ /_/|_/_/\__/_.__/\___/\___/_/_/_/
ekieboom@xs4all.nl      www.xs4all.nl/~ekieboom/


<Prev in Thread] Current Thread [Next in Thread>