View single post by JH12947
 Posted: 05-28-2024 07:05 pm
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JH12947

 

Joined: 07-14-2022
Location: Penticton, British Columbia Canada
Posts: 52
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Delta Motorsports wrote:
Greg,

I have followed the recent discussionon the sticking, front caliper with a fair bit of interest and would like to add my comments.

First. I did not mean to infer that the master cylinder was the culprit, but rather the booster push rod was in need of adjustment. With time the necessary clearance between the push rod and the rear piston of the master cylinder decreases until the piston can no longer fully return to its fully relaxed position. As a result the cylinder does not release hydraulic pressure, and the brakes remain lightly applied. You will note a threaded sdjustment on the push rod. Screw this a turn or two inward (shorter) and most non-release problems will be cured. Why this affects one wheel only I don't know. It just does.


Jim Medland


On my first reasonable length drive after the restoration (a couple of miles), my right front brake locked up and was smoking. I left it overnight and it was free in the morning. Good brake this morning and it did not lock up when pressed. I haven't driven it again.

The braking system is all new except the calipers, but new pistons and and seals. New hoses, hard lines and TR6 master cylinder. PDWA shuttle is centered and everything seems fine visually. The only issue I have found is that the affected disc runout is .007", exceeding the max spec of .004".

So I'm down to this pushrod adjustment, which I paid no attention to when I installed it. I'm assuming it is the rod as shown in the attached photo.

Does this job require removing the booster and master cylinder assembly and can anyone describe the process in a bit more detail? It seems odd that with a common pipe from the MC that both sides are not affected

I'm considering going for another drive to see if I can replicate the problem. Other than the piston, does anyone have any other ideas?

Attachment: Booster Cutaway.jpg (Downloaded 37 times)