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Old 11-01-2014, 04:05 PM
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Brake booster push rod adjustment

Hi guys
So I have just replaced the brake booster with one from crown and when it arrived the end of the push rod which has the adjustment was loose inside the booster.
After retrieving it I measured the rod length on the old booster and then replaced. First test run the brakes dragged on so I adjusted the push rod shorter a few try's until the brake didn't drag but now the pedal is very low.
I have heard there is a particular way to align the push rod and master cylinder and the brake drag may not have been caused by the push rod length.

Any advice would be good I need to get the brakes right.
I need to know how to adjust the push rod length ( should I take the measurement from the old one)
How to alight the master cylinder when installing onto the booster
.
Thanks in advance guys




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Old 11-01-2014, 04:26 PM
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Re: Brake booster push rod adjustment

Service manual doesn´t say anything about adjusting the rod. I would say that it is safe to use the same measurements of the old booster. Is there any way to adjust the input rod connected to the pedal?
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Old 11-01-2014, 04:29 PM
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Re: Brake booster push rod adjustment

Quote:
Originally Posted by Frango100 View Post
Service manual doesn´t say anything about adjusting the rod. I would say that it is safe to use the same measurements of the old booster. Is there any way to adjust the input rod connected to the pedal?

Hi Frango
No adjustment at the rod inside the car. Any advice on the master cylinder alignment ?


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Old 11-01-2014, 04:53 PM
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Re: Brake booster push rod adjustment

The only thing they say is for a helper to push the brake pedal while installing the master cylinder. I would start with the same measurements of the old booster. Can it be that the secondary push rod, from the booster to the master cylinder, is not aligned well?
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Old 11-06-2014, 05:49 AM
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Re: Brake booster push rod adjustment

So here's an update. I measured the old pushrod from the edge of the booster and it was 30.5mm the new on was 28mm.
I adjusted to 30.5 and took it for a spin. The brakes ended up binding after a few miles. I then adjusted again to 30mm.
All good, no low pedal strong brakes and no binding after a few trips.
So if you replace the booster without the master cylinder or vice versa you must adjust the pushrod to match them together and yes .5 of a mm makes a difference. The master cylinder must have a slight preload from the booster but not allow the relief valve to become blocked after the fluid expands with heat.

Now onto replace the ac compressor and dryer.
Cheers
Jon


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