Braking point

Mr Giugiaro · #1 (**permalink**) 08-19-2003, 05:27 AM

Hi, tricky brake problem, would welcome suggestions.

The brakes on my '72 2000 GTV are acting strange, at times the brake point moves further down - I start braking, then lift off a bit and occasionally I then have to push the brake deeper to engage it again. Fine again after you lift off. It is not really unsafe or anything, but I am worried as it could get worse. Anyone experienced something similar?

The brake fluid is full up, no leaks, both servos are connected and the brake master cylinder is two months old.

Thanks.

djone101 · #2 (**permalink**) 08-19-2003, 07:19 AM

Sounds like you have the twin servo set-up. This is a nightmare to bleed in my experience (as you have to bleed front and rear together) it has taken me a long time to get mine right and the pedal has been consistent once I got the whole sysem bled (new servos and master cylinder) That was until last week when the rear brake started binding - I'm hoping it's just a sticky piston....

So not much help from me but lots of sympathy.

**Gary Williams** · #3 (**permalink**) 08-20-2003, 01:32 PM

I had a similar problem on my GTV. The pedal would be firm one application or several, then at other times would drop enough to be noticeable. After bleeding the system several times and installing new brake master and new booster, we found the real culprits. Yes, plural. Front right rotor ever so slightly warped. Needed a dial indicator to find it. Left rear wheel bearing slightly loose. The retainer clips that hold the pads in the calipers seemed a little tight, acting to hold the pads away from the rotors. And finally, a brake linkage issue. My car is a '67 with the floor-mounted pedal box. The most significant cause of slop in the pedal was a worn mounting point where the clevis pin connects the brake master to the pedal linkage. The hole became elongated over 35 years of use.

The warped rotor pushed the pads away from the disc. The slightly loose wheel bearing had the same effect. The tight retainer clips held them away. The elongated hole for the clevis added play in the linkage.

aafoon · #4 (**permalink**) 08-20-2003, 09:10 PM

sounds like a bad brake master cylinder,the plunger is probaly getting worn.

**Gary Williams** · #5 (**permalink**) 08-20-2003, 11:23 PM

My point is that what appeared to be a bad master cylinder turned out to be several minor issues, none of which were the master cylinder or air in the lines. The car had a nearly new brake master on it. I put another on it. Neither solved the problem. What did the trick was replacing the loose wheel bearing, truing the rotor, and shimming the sloppy linkage. Sorry if I didn't make that clear.