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akrussell

Brake maintenance

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I don't want to resurrect the great brake fluid debate here but I will ask the following anyway. I recently got my Franklin Olympic out of museum storage where it has sat for the past several years. It has extremely low miles for a 24 year old restoration and I've owned it for nine years. It has silicone fluid in the brake system. In driving it both before and after storage, I noticed that the brakes squeal and most notably the passenger rear wheel is covered with black dust from the brakes. I also noticed that once the brakes are applied, the pedal tends to stiffen up and stay high as if the brake cylinder is locked into extended position. I pulled off the rear wheel and noticed that the forward shoe is almost completely worn off while the rear shoe seems normal. I have a set of wheel and master cylinders that have been completely rebuilt and ready to go. However, the rebuilder recommends that silicone fluid should not be used as it tends to swell the rubber parts and potentially locking the brakes, etc. Also, I've replaced the brake light switch on the master cylinder several times over the years and occasionally need to add fluid (I believe some of the wheel cylinders leak). I don't have an opinion on which fluid is best but the commonly mentioned problems about the use of silicone fluid appear to occurring on my car. Any recommendations or similar experiences? If I decide to replace the wheel cylinders and go to DOT3, how does one flush the silicone out of the lines?

Thanks,

Dan

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Dan:

I too don't want to start another fistfight over the topic...

I will simply relate my experience with DOT-5...

I used it in the full-system rebuild of my 1941 De Soto about six years ago.

Aside from having a nasty time bleeding the system (long story), it has worked well for the last six years /15,000 miles.

I have gone through three NEW stoplight switches: all of them have failed after about three months.

I finally substituted a mechanical switch from a '47-'54 Chevy truck, mounted to the toe-board, with a finger that rides the pedal arm. Dad's 1930 Chevy has a similar switch on it's mechanical brakes.

Does your Franklin have Lockheed brakes with fixed anchor pins?

Your lining wear question on the right rear wheel strikes me as one(or more) of the following:

1) Piston stuck in bore, causing shoe to drag.

2) Weak or broken return spring

3) Incorrect adjustment of the anchor pin and/or wear adjuster...

As to flushing system, I would first flush with denatured alcohol (mind the paint!), and disassemble any cylinders and clean-out separately, then air dry for a day or two, then flush with whatever type fluid you're using (I used DOT-4 on my last full system rebuild - still Glycol-based, but more corrosion inhibitors than DOT-3; is also compatible w/ DOT-3), then finally fill & bleed.

The foregoing advice is strictly based on my personal experience...other folks seem to have no troubles with the DOT-5 stuff...

We'll see what others have to say...

smile.gif

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RE:"I also noticed that once the brakes are applied, the pedal tends to stiffen up and stay high".

I have to agree with all Franks suggestions about the possible faults at rear wheel brake but I would add that the above comment about "Stiffening feel" would sound like the master cylinder push rod may be misadjusted and not returning to a neutral position thus storing hydraulic pressure in the system when it wants to be relaxed. Browse back a few weeks or so and read similar situation encountered by Roadster Rich and his 1930 Chrysler. Stude8

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RE: MC pushrod adjustment...

This would cause the piston not to be able to fully return to the end of it's stroke, and uncover the relief port & allow the fluid to return from the wheel cylinders...thus keeping the brakes applied after you've taken your foot off the pedal...

This may also be the result of the rubber inside the MC not being happy with the DOT-5 and swelling or getting gummy...

What year Franklin are we talking about here ?

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Thanks everyone for the insight on this. Perhaps the condition of the brake system has been exacerbated by the lack of running time on this car. I need to do some checking based on the discussion here and will provide an update soon.

The Franklin Olympic is a '33 model year based on a '32 REO Flying Cloud chassis and running gear. It does have Lockheed brakes.

Thanks again,

Dan

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