Phil Ethier wrote:fter this.
>
> I have sort of the opposite problem. Since I bought the TR4, the brakes
> have been solid, high, and immediate. Not the slightest hint of needing to
> be pumped up, ever. The classic "hard pedal".
>
> I went to an autocross last Sunday. Thought it would be fun to let my
> buddies see me slide around on the brick-like tires it is currently wearing.
>
> I launched, then made a few turns, accelerated, changed up to second. Then
> I needed to use the brakes for the first time on the run. The pedal dropped
> more than half the travel.
I had the same problem with my TR4 vintage racer. It took three years and trying
LOTS of things before we finally tumbled to the root cause. On the way to the
solution we tried everything -- including aftermarket residual pressure valve
for the front circuit.
Something is happening with the front wheels to push back the pistons in the
calipers during cornering. With my car, this happened only after a
left-right-left sequence of corners.
It could be loose wheel bearings, but that was not the case in my car, and is
apparently not the case in yours. You could check to make sure that the nut
holding the front spindle in the upright is still on tight. They have been known
to loosen, hard as that is to imagine. In my case, the cause was that the rotors
had been turned a couple times and were under spec on thickness. I completely
solved the problem with new rotors. I have since found on my car that this
problem will start with any irregularity in the rotors -- taper, out-of-true on
flatness, etc etc. Therefore on the race car I replace them probably once a
year, but that is only on a car that uses up a set of Carbon Kevlar front pads
in two racing weekends..........
Good luck.
--
TR6 -- 29 and still running
TR4 -- 39 and being rebuilt
uncle jack -- down but not out
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