47 braking issue question

On my 47 sedan, the braking has become an issue.

When moving forward and the brakes are applied the car goes dead left, When backing up and the brakes applied the car goes dead right.

Brakes have been bled several times same result.

Brake shoes are on correct, short shoe front, long shoe rear on each front wheel.

Can a bad brake hose right front cause this? Anyone?

Comments

  • I would replace both front wheels cylinders and hoses. One of the cylinders may have a stuck piston, or one of the hoses may be collapsed intside.

  • With the wheels off and rotating the drums while slowly applying the brakes all appears normal. All 4 wheels bleed normal for a good firm pedal.

    I have had the wheel cylinders apart, honed them and reassembled all, same result.

    Ideas Anyone?

  • Are your wheel cylinders all the same inside diameter? Bought a car , was rebuilding the wheel cylinders and discovered that one side was a different diameter that the other side. After you honed them did you put new parts in the wheel cylinders?

  • To me the obvious problem is the left front. Something is "grabbing" that drum. Any fluid on the linings? Other consideration is something broken in the front suspension. Have you checked that thoroughly?

  • lostmind
    lostmind Expert Adviser

    Was it working ok , than developed the problem? Or after recent work done?

    Replace both front hoses, bleed , adjust , retest.

    You can't usually tell if they are coming apart inside.

  • If a hose bleeds properly could it still be too plugged to work properly when braking?


  • I've had the system apart several times no signs of leakage or faulty parts brakewise. Will the left front grabbing issue cause the car to steer dead right when backing up and dead left when moving forward?

  • lostmind
    lostmind Expert Adviser

    You can force fluid through bad hose with the master cylinder. It's the fluid returning to master where the collapsed hose comes in. Won't release pressure right away, Has the cylinder pre loaded and applies before the other side.

    Are you sure the front end parts are ok? Loose bearings in wheel should be obvious.

    Toe in and camber can make a difference in reverse and forward.


    Bad brake lining ( mismatched materials) also possible.

    You still haven't mentioned if this is after recent work , or if car was working properly then suddenly developed the problem.


    Don't be stingy with the info and we can help.

  • No recent work performed. The car had sat for many years and now just recently been put on the road. The wheel/brake parts all look good. I am going to replace both hoses which I have ordered. I have done enough brake jobs to feel that this is something a bit unusual.

    I feel the front end is not the issue as the car tracks straight with no drift R or L until applying the brakes. It is drivable as long as I hang on to the steering wheel when braking. Wheel bearings have no play and are greased properly.

    I realize I could parts replace everything until I find the problem but I kinda like to know why things do what they do before fixing them. I Was hoping someone may have experienced like symptoms.

  • lostmind
    lostmind Expert Adviser

    I think you're on the right track. Report back with results.😁

  • So, new hoses, new wheel cylinders, new brake line to R front, re-bled the system. No change, still pulls hard left when braking while moving forward and hard right when braking while backing up.

  • lostmind
    lostmind Expert Adviser

    😥

    Can you post photos of the shoes on both sides. ? I'm thinking different lining material?

    Not much left on the front if the suspension is tight. I suppose if camber was way off on one side it could affect it , but you should be able to see the difference if it's enough to make it pull with brakes.

    I'm assuming you checked the rear wheels, at least to see if they turn freely when jacked up.


    Possible a brake cable locked?

  • Not sure how the rear wheels would cause the steering wheel to jerk hard left when applying the brakes but I will recheck them.

    I thought in the beginning that the brake shoes were the culprit as the previous owner had placed the shoes with the shorter linings 9 1/2" on one side and the 11 1/2" shoes on the other. I felt surely that was the problem but it made no difference once corrected. The shoes and the linings look fine and worn very little.

    Wouldn't a brake cable lock be a constant problem vs just when applying the brakes?

  • Glowplug
    Glowplug Expert Adviser
    edited November 2023

    weak or wrong brake springs, as was stated in an earlier post, a brake cylinder piston that drags or cocks when brakes are applied. Drum that is out of round or bent, linings that were at one time soaked with brake fluid and dried. These are physical brake defects that are difficult to observe and may be the cause of your phantom problems. Good Luck.

  • I disagree. Grabbing is what the brake are suppose to do. The right front is not grabbing enough.

  • Jon B
    Jon B Administrator

    I've been having the same problem for several months (with my '37).

    One question: if you are driving on a dirt (or loose gravel) road and hit the brakes, does the left wheel lock up and leave a "skid mark" in the gravel, for several feet?

    My problem brake is on the right side. The car lurches to the right and leaves a track in the loose dirt/gravel of the driveway.

    When you do get the problem figured out, please share the solution with us!

  • Two days ago, I swapped the front drums. As in moved the L to the R and visa versa. So far, I'm seeing a significant difference of about 80% better braking action.

    I have no idea why this worked, but really don't care. Now to see if it lasts.

    Jon B if this works for you maybe we have found a miracle cure. lol