I have had my '72 2+2 for 7 years now. Working slow and steady through the restoration.
I’ve recently had the clutch replaced and asked the mechanic to check the brakes. He claims brakes appear to be just fine, with new lines and master cylinder.
The reason I asked him to assess the brakes is - whenever I drive the car for more than 10 miles, it is as if the front brakes are being applied and the nose “dives” in between gears. And the more I travel, the more resistance and nosediving she demonstrates.
The first few miles, before she heats up, are just a sheer pleasure. By the end of the drive, she is pushing to get back into the driveway!
Has anyone ever experienced such a phenomenon? If so, could you shed some light on what this might be or what to inspect for?
Could it be bearings and not brake related whatsoever?
Another potential clue - during one longer voyage, I actually had black “goop” dripping out of the perforated original rims. Hmmm?
Would love your thoughts in diagnosing and addressing this matter.
I’ve read a few reports here of the old flex hoses having separated and collapsed inside layers that would trap fluid but not let it flow back when the brakes where released. It would slowly seep back so that subsequent drives gave normal operation…for a while. The anything rubber should be replaced and the entire system flushed.
Check the hose between the reaction valve (on the end of the master cylinder) and the rear section of the servo. Since the master was replaced, it’s possible that the clamp was insufficiently tightened, or the hose was damaged in the process. I’d replace that hose as a matter of good practice. If that doesn’t fix it, remove the plastic reaction valve (careful not to lose the screws), but leave the round plate in position. insert a thin tool into the hole in the center of the plate as far as it will go and hold it there with light pressure. Have someone press on the brake pedal. You should feel the pressure in the cylinder working against you, you won’t be able to hold it back. When the brake is released, the piston should go back smoothly. If this isn’t happening, the master is garbage. If it does happen, you’re going to have to rebuild your servo/slave assembly.
Whatever you do, DO NOT continue pushing your car through resistance. Driving with your brakes engaged will damage your calipers.
I agree that something is providing enough resistance to hear your wheel bearing grease and make it runny. I would check wheel bearings. Is it just one wheel with the goop? Check that one first. If it’s both then you may be able to eliminate this idea as I don’t know that both would go out at the same time but if it’s done this for a while then it’s possible. I’m sure the rotors getting that hot could transfer the heat from the hub to the grease as well. It’s pretty well narrowed down though to that area of the car so pull the wheel it should be obvious.
Yes. Continuing to “run through resistance” is heating the brakes, and will cause failure of the calipers, pad and eventually bearings. Fix the brakes before this becomes a much bigger problem.