'57 Manual Brakes Issue (Left Front Grabs)

[arussharris]

Hello,

New member here and I'm trying to resolve a front drum brake issue I'm having with my 1957 which has manual brakes and one master cylinder.

My left front brake pulls when applying firm brake pressure at cruising speeds which scares my wife from driving her.

I took the wheels off, order new springs and adjusted the shoes...all to no avail. After I finished the adjustment process I realized that actuation of the brake pedal was not causing the shoes on the right side to expand.

This led me to believe that fluid was not getting to the right side. I loosened brake connector assembly on the left side and noticed fluid coming about on both sides which leaves only the crossover brake line that goes from the left wheel to the right side or the right brake cylinder. (attached links for photos of both parts)

https://www.npdlink.com/store/products/thunderbird_connector_assy_front_brake_at_lh-139804-641.html

https://www.npdlink.com/store/products/thunderbird_brake_line_crossover-139845-641.html

I cant determine whether or not the crossover line is corroded, broken, or clogged which could be keeping fluid from making it over the left side or if the right wheel cylinder is bad.

I was hoping to get some insight from you fine experts prior to purchasing unnecessary parts and wasting my time.

Lastly, she's had the front end jacked up for over a week as I've tried to narrow this issue down. Could she possibly just need to be lowered and have the brakes pumped a handful of times with the engine running in an attempt to get that fluid over to the right side?

Thanks a lot for the help.

 

[gbhrps]

arussharris,

You have correctly found the offending side that's not braking. If the car pulls left when you brake, the right side has a problem, and vice versa.

I doubt that the hard line to the right side of the car is bad (but it could be). More likely the wheel cylinder on the right side is seized or leaking and not doing its job, and needs rebuilding (if you know how to do it, and you don't give me those vibes) or needs replacing (which I suggest you do, if necessary).

The other problem could be that the rubber flex hose on the right side has collapse d internally, and is not allowing fluid to get to the wheel cylinder on that side.

You should have a feel for when those brake components were all changed. If not, or if never, change all 4 wheel cylinders, both front flex hoses, and flush the entire brake system with new brake fluid.

These old small birds have a single brake line from the master cylinder to all four wheels. If something goes wrong, there is no dual crossover system as more modern cars have to act as a backup. Don't go stingy on a fix.

You can check if that one wheel cylinder is bad, by pulling its flex hose and using an air compressor at the wheel cylinder fitting (where the hose would connect) to see if it moves when you pressurize it. If it does, then change all the flex hoses, the two up front and the one to the rear axle. And if the one wheel cylinder is bad, change all four of them, because the others are not far behind that bad one. Good Luck!

Gene

 

[arussharris]

Thanks a lot Gene, I really appreciate the help (even if it came with a dig, haha).

I am definitely a novice but the baby bird was my grandfathers and I'm trying my best to keep her in good health. I'm learning these maintenance issues are mostly an exercise in patience. I'll be sure to look more into the flex hose and wheel cylinder instead of springing for the crossover line.

 

[arussharris]

Gene, checked the crossover line at the right flex hose and there's fluid there so we've narrowed it down to the flex hose or the right wheel cylinder. Thanks for the help, will investigate further tomorrow.

 

[arussharris]

Gents I'm going to take off the right wheel cylinder tonight and attempt to take her apart and clean up the components. Is there anyway to visually assess whether or not the cylinders in good working order and hasn't seized up? Thanks for the help.

 

[gbhrps]

arussharris,

Rebuilding a wheel cylinder involves new rubber cups and seals, but more importantly, the cylinder bore needs polishing with a special tool to remove any corrosion and pitting to prevent future leaks.

If yours doesn't move when the brake pedal is pushed, its beyond repair. Trust me, .... replace it. Leaky cylinders MAY be able to be repaired, but not always.

While these rebuild kits are cheap ($6 or so dollars a wheel cylinder) why bother when new wheel cylinders are $15 a piece, at least in Hill's Thunderbird Center catalog? Check online "thunderbirdcenter.com. I've dealt with them for years. Decent prices, quick delivery, and the advice to make it all work.

More importantly, if one wheel cylinder is bad, all of the others will be at nearly the same state. After all, they may all be original, and 60 years old.

For the 2 or 3 hours and $75 in parts it will take to replace all 4 wheel cylinders and rebleed the system, it doesn't make sense to take a chance on fixing just one. Do them all and you'll be good for the next 5 years or more.

I never intended to take a dig at your abilities or knowledge. I apologize if my comment came across that way! Your description telegraphed that this is your first attempt at brake work of this nature. And while making a car go can be successful or not for a DIYer ... it has got to be able to stop, or someone may pay with their life.

 

[arussharris]

Thanks for the sound advice, no offense taken, just having some fun. Ordered four new cylinders that'll hopefully arrive early next week. Had some free time and decided to dig into the old cylinder to hone my chops. She was definitely beyond repair but good to get some practice.