[Terry M. Hunt]

I finished the restoration on my '65 2+2 around 1994. Replaced all the brake shoes, brake hoses, wheel cylinders, master cylinder, had booster rebuilt, and switched to silicone brake fluid. I should have replaced the hard brake lines then, but didn't get around to that until last summer. On this second brake go round I replaced all hoses, all hard brake lines, front shoes, and front wheel cylinders. Had a struggle getting a good seal at all the joints, even though I used steel lines, not stainless lines. Finally got everything tight. Did a couple of two man brake bleeding sessions and pronounced all was good. Did a long trip from Atlanta to Daytona for Turkey Run and numerous shorter trips to local shows and cruises. What I'm noticing now is that the brake pedal travels a good bit further than it used to in stopping the car. I don't notice anything else amiss in how it stops. It is a little unnerving to feel the pedal travel that far before enough force is produced to stop the car. It is also weird to look down when the car comes to a stop and see how close to the floor the pedal is. This is not the way this system used to perform. The pedal didn't travel as far to get the car stopped. The braking action began at the top of the pedal's arc of travel and was not as close to the floor when the car came to a stop. I can apply the brakes and hold the pedal down with the car at rest and the pedal does not sink. The amount of travel does not seem to vary, it just seems like too much.
When I installed the new front shoes, I tried to adjust them out as far as I could without creating too much drag. I then went to an empty parking lot and went through numerous back up/drive forward cycles to get the automatic adjusters to move the shoes out to the ideal position. Since then, I've gone through even move backward/forward cycles just in the course of normal driving. What is up with this issue?

[mgarblik]

Not sure what's up but an inspection of the shoe to drum contact is in order. If the new shoes were not arced to really fit the diameter of the drums, this could be the issue. When the shoes were new, even a small contact area on each pair would produce decent friction. Now that you have made some trips with the car, if the shoe to drum fit isn't using most of the friction surface, the shoes have glazed and a lower pedal results to get the car to stop. A visual inspection should confirm this. If you have good shoe to drum contact, I would tighten them up some. Other than air in the system, there isn't much else that can give you a low pedal. I would also verify that the self adjusters were not mixed side to side at any time while work was done. As you cycle the adjuster arm with your fingers, as the arm moves down, the star wheel should make the link longer. Good luck.

[DOC]

is there an upper hole in your brake pedal you can move the MC push rod to? That will help if there is. I am not familiar with the 65 models but on the 60's /70's stuff that makes a difference.

[Engine-Ear]

Just throwing this out there: even TINY amounts of air in a DOT-5 fluid system can cause sh!t like this to creep up.

Not sure what also to say, but I have sworn off DOT-5 fluid after too much aggravation from minute amounts of air in the system causing too many driveability (stop-ability?) problems.

[Heybuck]

Just a thought on this, are you sure you have the brake adjusters in the correct side?

I think I recall that there is a specific left & right side and if that's so and they are wrong, you might not be getting the correct distance between the shoe and the drum.

[Redpiston]

Isn't there a main and secondary shoe? If you have those flipped you might get more travel also.

[Terry M. Hunt]

I've been using silicone brake fluid for over 25 years in 4 cars, so I'm familiar with its drawbacks. Haven't had this low pedal issue with any of the other cars. Still, the easiest thing to try first is another bleed session or two, so I'll do that. Given the fact that I started with a completely empty system, I can see how it may take longer(more sessions) to purge all the bubbles. I'm positive I got the short shoe and long shoe in the correct position, because I recall searching on these forums to confirm what shoe went it front and what shoe in back before I started the brake job, since I recall the '65 shop manual(and other years as well) showing this backwards. I did the brake work one side at a time, so there would be no chance of mixing left and right parts. The adjusters went back on the wheel they came off of, and since I did not have this low pedal issue in the past, I don't believe the adjusters have gotten mixed up. However, if further bleeding doesn't solve this, I will pull both front drums and recheck shoe position and adjuster function. Seems like it has to be one these three things causing my problem.

[lust4speed]

Air in the line is going to give you a spongy pedal. A pedal that goes farther to the floor before engaging normally pretty much has to be nothing more than an adjustment problem. This can either be at the wheels or the brake rod contacting the master cylinder piston up on top. If you replaced the master cylinder, the new one might have a deeper center hole.

[Terry M. Hunt]

I've known about arcing shoes for many years, but never had it done on any of the brake jobs I performed on 5 different cars. Did some web surfing today on the subject and saw a couple of videos of different brand machines doing this process. I can understand how this would produce ideal contact between shoe and drum, but wouldn't the shoes wear into this same ideal contact pattern over time anyway? Any guess about how long it would take for this to occur?

[Deadhead]

Is rod correct length? Delco vs. Moraine or a new dual vs. old single cyl. may have caused this? Easy to have a Prob. here if the whole system was redone at the same time. A rod that is too short could easily cause the Prob.

Really sounds like air, but if stopping fine, then it could be the rod or pedal hole position issue. Nothing creepier than thinking you will run out of pedal when needed.

[Terry M. Hunt]

The master cylinder and booster were not changed during this latest brake work session, so there is nothing related to push rod length or attachment to brake pedal that should be an issue.

[Terry M. Hunt]

Pulled the front drums back off and checked for proper function of self adjusters. Everything seemed okay, but I replaced the star wheel/adjuster link anyway on both sides. Didn't notice any strange wear pattern on the new shoes. Put the drums back on and adjusted the shoes out to a slight drag. At the first stop, the car pulled to the right. I did 6-8 back up and stop cycles and eliminated the pull. Extended the test drive and found the pedal height was back where it had been. I'm guessing that the low pedal problem was a result of me not adjusting the shoes out far enough when all the previous brake work was done. I do recall the drums had almost no drag as I rotated them then. The master cylinder was still full, and I saw no evidence of leakage anywhere. Looks like I may have this solved. Thanks for all your ideas on this issue.

[Ragtop Man]

I love a happy ending....

Question for the experienced darksiders: is there a factory spec for drum 'drag' (assuming preload is properly set with the wheel bearing?)

Obviously different from f/r, but the post that suggested maybe pushing shoes out was right on.

Brake 'adjustment' was common in the day before discs were on everything, due both to wear and system 'relaxation.' We forget today there was a garage on every corner because every system on every car needed attention frequently. Fuel pumps, water pumps, carburetors, ignition, brakes, lubrication were all common tasks. Now the neighbors find it novel when someone crawls under a car to check it out and do routine work...

[aceaceca]

Add to the possibles list an internally leaking master cylinder. It may not have liked the synthetic fluid.

[Hotrodjohn71]

Have you found a solution to this issue? I have a similar issue.

[Terry M. Hunt]

Reread. Post # 12 above.

[Hotrodjohn71]

Hi Terry,
In your first post, among the many things you tried to get your brake pedal back up to a good position, you did many back up stops to get the shoes to adjust to their best adjustment, but you said it didn't seem to remedy the issue.
But in post 12, you did more back up stops, and did you say that fixed the issue? Was there anything else you did to get the pedal good again?

[Terry M. Hunt]

I think I just did not have the shoes adjusted far enough out to begin with. So much so that the auto adjusters could not compensate during the relatively low number of times driving back and forth that I attempted to get the auto adjust to solve my low pedal problem. During the second go round, I adjusted the shoes out further than before. This resulted in more drag on the drum when rotating it by hand, but not so much that excessive heat was being generated, etc while driving. It’s hard to describe “how much is enough” on this step because it’s kind of subjective and based more on “feel, educated guess, and trial and error”. From that point, the auto adjusters had little or no adjustment left to make to move the shoes out further so the pedal travel returned to normal. That’s my theory based on all the other stuff I investigated, tried, etc.

[Engine-Ear]

Originally Posted by Ragtop Man

Question for the experienced darksiders: is there a factory spec for drum 'drag' (assuming preload is properly set with the wheel bearing?)

Factory specs in the '62 Chassis Manual refer to feeler gauging the gap between shoe and drum. Haven't tried that (would be an interesting comparison to my method).

FWIW, my method is to adjust the shoes where there's about 3/4 turn of the tire with a good tug. The shoes will "adjust in" from there. NO pedal travel before grip. And I don't care if it takes 500 miles off the life of the shoes over their tenure. I have 40,000 miles on the Raybestos riveted shoes I put on my Bonneville in 2002 doin it that way.

[389]

Adjust the anchor pins and the brake shoes. manually. Those self adjusters rarely have the brakes correctly adjusted. I usually remove them and manually adjust the brake shoes.

https://www.brakeandfrontend.com/dru...cient-devices/