Author Topic: Brake Pedal Travel Issue  (Read 1289 times)

Linton78

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  • Australia, New South Wales, Bundanoon
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Brake Pedal Travel Issue
« on: December 06, 2023, 06:59:12 »
Hi, hope someone maybe able to help me with a brake issue.

Car: 67 250SL RHD

I have too much brake pedal travel.

Air has been bled from master cylinder and system.

When I place the pressure bleeder onto the master cylinder, the brake pedal travel is perfect.

What I have noticed is that when the brakes are released, the front brake pads (on both calipers) retract off the disc enough that you can jiggle them - they are loose with a gap between the rotor and the pad.

When the pressure bleeder is used, this small gap is taken up and the pedal travel is perfect.

It seems that the initial part of the brake pedal travel is taking up this gap and then applying pressure on the pads/rotor.

Is it normal for the front pads to retract into the caliper when the brake is released? It seems very strange.

Is this a master cylinder issue? Seems odd that both front calipers are behaving in the same way.

Thanks,

Linton

BobH

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  • United Kingdom, England, MALDON
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Re: Brake Pedal Travel Issue
« Reply #1 on: December 06, 2023, 22:04:19 »
Hello Linton, i'm no expert, so hopefully someone else will advise, but you could possibly have a problem with the brake hoses, either swelling or collapsing, so the fluid isn't running effectively in both directions, maybe worth checking them
February 1965 230SL Automatic
UK delivered RHD
Papyrus white, blue hard top & hub caps
Blue soft top
Blue leather

Benz Dr.

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  • Canada, ON, Port Lambton
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  • Benz Dr.
Re: Brake Pedal Travel Issue
« Reply #2 on: December 06, 2023, 23:43:32 »
There's an eccentric adjustment on the push pin at the back of the brake booster. This part has a small notch on the head of the bolt to indicate the highest point of adjustment.
Turning the bolt all the way back towards the firewall will give you minimal brake pedal travel.

Most cars I look at are not adjusted properly.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC