I was not very precise in my description of the problem. The pedal box was
completely refurbished and the pedals return smoothly w/o problem. The
brake M/C plunger, however, has been slow to return the last fraction of an
inch, resulting in a bit of extra play in the pedal. This goes away when I
tap the pedal and the plunger snaps up the last bit.
I took the restrictor valve apart yesterday, cleaned the internals (all two
parts), and reinstalled it. There is not much there to go wrong, and all
the internals are metal. We'll see how it behaves for a few miles.
Thanks for the ideas.
Dean Mericas
1965 TR4
1974 2000GTV
> -----Original Message-----
> Date: Sat, 14 May 2005 09:54:39 -0700
> From: "Randall" <tr3driver@comcast.net>
> Subject: RE: TR4 brake restrictor valve
>
> > Since then, the brake pedal tends to stick part way up.
>
> The pedal return spring should be strong enough to lift the
> pedal all the way up, even if the MC doesn't return. Sounds
> to me like your return spring is weak or missing, or the
> pivot is binding. The pivot should get a drop of oil once in
> a great while but it seems most people don't do this.
>
> > Now I'm thinking that the brake cleaner may have messed up
> something
> > in the brake restrictor valve. The part appears to be NLA.
> >
> > My questions:
> >
> > 1) Is this something that can be refurbished or replaced with a
> > similar part from another car?
>
> It can certainly be disassembled and cleaned.
>
> > 2) Is the valve necessary? Rimmer shows it as not always
> being fitted.
>
> It wasn't fitted to the first 7,000 or so cars with front
> discs (TR3), then was discontinued sometime during TR4A
> production. AFAIK all TR3A/3B/4 had it.
> Might be that the softer suspension of the IRS cars reduced
> the flexing of the front spindles, I don't know. Or it may
> have just been a response to what I understand was a fairly
> constant stream of complaints about the brakes dragging all the time.
>
> Removing the valve entirely will cause your solid lines not
> to fit, but it's not absolutely essential otherwise. The
> approach I took was to remove the plunger and spring from
> inside the valve, then put the valve body back into place.
>
> You should be warned that you may experience low brake pedal
> after "spirited"
> driving ... this is what the valve was supposed to prevent.
> A quick pump will bring back the pedal and allow you to stop.
> I never found it to be a problem on my TR3A (which I did
> sometimes drive quite hard, we have some lovely twisty
> mountain roads around here) but it might be upsetting if you
> weren't expecting it.
>
> Randall
|