About brakes

[watson2]

Hi guys.
I would like to have your opinion about a matter that I think could be improved.
I never drove another 230 SL like mine ( an automatic 1964 model) so I cannot make comparison. So I ask to you.
When I bought my car it had good brakes with a 'long' pedal. It had too much play (not so much, but beyond what I think is the normal one) , but above all the pedal has a long run to get the most out of it.
So have been changed:
-all the rubber hoses,
-the rubber rings on the calipers,
-the valve and the hose between brake servo and air intake manifold
Well : the pedal was still 'long'.

So we revised the brake servo and changed the master cylinder.
Nothing : the pedal is 'long'

My car has Girling front calipers and rear drums.
It remains stable when braking and is able to reach the wheel lock easily.
Nothing changes if the pedal is 'pumped' twice or three times.
Simply the pedal is 'long'.
Any advice?
 

[Pawel66]

Is this not the question of adjustment done by the cam/eccentric screw at the booster/pedal lever connection?

Sorry if I march ahead of orchestra...

Try search: "brake eccentric"

[Benz Dr.]

I find the same problem on almost every car I look at. You can adjust the free play out at the eccentric and that will shorten the pedal travel a lot if it's really out a long ways. I've seen a couple of cars where the brakes started to lock up after repeated braking so I had to turn the eccentric back a little bit so the brakes would release but this is a quick and easy adjustment.

[watson2]

Thank you Pawel and thank you Benz dr.
I began reading and I found what I looked for.
All of you are precious people.
I attach images of the workshop manual ( the eccentric is the nr.3 in the first and second image)
and of Haynes manual (in the image 9-14 is the nr 2)

I'm only surprised that my last mechanic knew this problem and he didn't fix it.
I'll investigate to understand if he knows the existence of the eccentric bolt.
I would be disappointed if he did not know  :-)

Last question: the car rolls freely, but there is almost always a slight whistle 
coming front the disc brakes , while the car moves. What can be responsible of this squeak?

[stickandrudderman]

Don't underestimate the simple stuff: Are the rear shoes adjust correctly?
Also, if you have any wheel bearing play you can get "pad knock off" which will give a long pedal.
If you pump the pedal does it go short?
If you isolate front from rear using a brake pipe clamp does the pedal get short?

[watson2]

Hello Colin!
I will evaluate everything you suggested.
The bearing play is the one that can be considered normal. It was corrected about 1 year ago.
No noise coming from wheel bearings.
About pedal pumping I  wrote that nothing changes and for the front/rear insulationno test was not made. We will do
if, after having verified the eccentric, things will not change.

[Benz Dr.]

Don't underestimate the simple stuff: Are the rear shoes adjust correctly?
Also, if you have any wheel bearing play you can get "pad knock off" which will give a long pedal.
If you pump the pedal does it go short?
If you isolate front from rear using a brake pipe clamp does the pedal get short?

I agree that all of the basic stuff should be looked at but a quick look at the eccentric bolt will tell you if the notch is pointing in the wrong direction. I generally set them pointed towards the firewall which is the highest point on the eccentric but sometimes that can be too much as every can can be slightly different. Your mileage may vary.

[Shvegel]

Thank you for posting the picture.  I am restoring my 280SL and I had a question about which way the eccentric bolt was installed through the steel pivot.
 Mine was installed with the bolt head away from the fender as pictured but I thought it would make a lot more sense to have the bolt head with the marking toward the fender where you could easily see it. 

[watson2]

It's a pleasure, Shvegel, to be usefull to someone, specially when I am the first to be helped in this well of science that sl113.org is.
If you need a translation of the italian text , please  tell me

At last , thank you to all of you! Here is my eccentric.
The notch is forward oriented. We will turn it at least 90° clockwise (towards the firewall) and a new evaluation will be made.
It's not relevant that the bolt direction is opposite to the original one. It's clear that the 'fork' has been rotated 180°
and the effect of the movement of the cam is always the same.
 
Above all we will pay attention to the return of the oil back in the pump.
With a servo with a poor play (on another old car) it happened to me to remain blocked in a corner after 3 or 4 strong braking. :-)

[Pawel66]

Flavio, ok, so as your car is now almost fixed and safe, I guess it is now ready to give our wives a lift to from Milan to Serravalle for shopping! 

[GGR]

Hello Flavio,

if the ecxentric bolt adjustment doesn't fix the issue, you may check your rotors for wraping and your drums for roundness. Any defect will push the pads and shoes more than they should and translate into a  longer pedal travel.

Ciao

[watson2]

Thank you GGR. I will remember your advice.
In a few days I'll get back my car and I will let you know