Spongy Mechanical Brakes
 

I just spent the last couple of days changing out my bonded composite shoes for new woven shoes and linings. I have arced the shoes to the drum and have them centered. New springs, new rollers and pins. New brake rods were installed last year.

My challenge is the brakes feel spongy. Yes they will stop but the pedal doesn't feel firm, it feels soft. I have driven other A's with mechanical brakes and they have a harder pedal.

I have used the brake buddy to adjust the brakes 60-40 back to front.

Good thing I chose to do this as I found the drivers side rear wheel bearing was bad.

What am I missing???

Re: Spongy Mechanical Brakes
 

Yo, Okie Brother,
Iffin' you got 1 or 2 brake rods with some small wiggledy woggles in them, they can feel soft. Maybe as your shoes wear in to the drums a little, the "feel" may get "harder." OH! & throw away that board & adjust each wheel 'til it just locks up & back off 3 or 4 knotches, TRUST me, I do know what I'm tellin' you WORKS! Bill W.

Re: Spongy Mechanical Brakes
 

What is the result of mounting the anti-rattle springs on the wrong side of the brake rod nubs??

Re: Spongy Mechanical Brakes
 

Then the won't help return the brake pedal. If they push againt the bump in the rod from the wrong direction then they are helping to apply the brakes.

Re: Spongy Mechanical Brakes
 

If the drag is right it should take the sponge out of the pedal-assuming all your mechanicals are good:confused:

Re: Spongy Mechanical Brakes
 

Ahhhhh........Power Brakes

Re: Spongy Mechanical Brakes
 

Re: Spongy Mechanical Brakes
 

no bill,
you have air in your system

Re: Spongy Mechanical Brakes
 

I don't understand all the troubles some people have with the mechanical brakes. Mine work perfect and are no harder to apply than the hydraulic brakes on any of the older nonpower assisted cars. I can skid my wheels anytime I want, stops straight, don't fade...work great.

Re: Spongy Mechanical Brakes
 

GasX takes care of that.:cool:

Re: Spongy Mechanical Brakes
 

TinCup, Check the cross shaft for slop in the bushings also check the brake and clutch pedal shaft and bushings for slop . All pins need to fit without slop , You can use oversize pins to compensate for wear. Bubby Sharp in KY

Re: Spongy Mechanical Brakes
 

Spongy? Are the brake rods bent?

Charlie Stephens

Re: Spongy Mechanical Brakes
 

I've seen guys spend all their time/money on the four corners of the brakes with disappointing results only to find that the service brake cross shaft was sloppy. If the cross shaft is compromised, all your work down stream will likewise be less than effective.

Re: Spongy Mechanical Brakes
 

When I replaced the brake rods last year I replaced all the pins. Some of them required the oversized pins. The cross shaft is not sloppy.

Re: Spongy Mechanical Brakes
 

Maybe have someone exercise the brakes whilst you inspect the movement from pedal to wheels, you might find something unexpected.

Re: Spongy Mechanical Brakes
 

As stated above, two things to really keep an eye on, first have someone step on the brakes while you really check to see if the brake rods flex or are bent, after all they are very old.... The second it what bill said, try manually adjusting them. as a side note, did you cut the drums, or measure them? are they in spec? And lastly new pads sometimes need to seat, so it may be that they just need to be driven, sometimes a quick sand paper rub across them speeds that up....

Re: Spongy Mechanical Brakes
 

You probably already checked this.

But FWIW, if the right rear brake lever, (camshaft lever), was installed on the left, & the left rear brake lever was installed on the right, the rear brake levers are at a slight incorrect angle for proper alignment; hence, the rear brake rods are tightly arched like a spring as opposed to being straight.

Not all new rear brake levers are marked "RH" & "LH" -- then some get confused with "RH" & "LH" as opposed to referring to driver's side & passenger's side.

In not observing the slight angle on tops of rear brake levers, it is easy to incorrectly install same.

Even if this is not the problem in your case, it may help someone to be cautious on a future brake job.

Another cause for a sponge effect may be that a space exists between the brake band(s) & the brake shoe(s) at a location (or locations), between pairs of rivets; hence when brakes are applied, the brake band has to be compressed before it contacts the solid brake shoe for full contact with the brake drum.

Just keep looking -- probably something very simple.

Re: Spongy Mechanical Brakes
 

if the other possibilities not already suggested do not pay off, shoes that are not exactly centered feel spongy. Also, if one wheel or more is adjusted more loose than the others, the pedal will feel spongy too.

Re: Spongy Mechanical Brakes
 

Try going through the adjustment procedure without that board.See what you have then.

Re: Spongy Mechanical Brakes
 

The newly rebuilt brakes were spongy on my roadster. I ran it a little while and then completely readjusted. Now they are firm.

I don't bother with the 60-40 bit. I recall the modern thinking is you don't want the rears to lock up first, as it causes loss of stability (i.e. back end breaks loose and the car tries to spin around).