[ROVERNET - UK] more servo woes

[peter king]

hi Steve.

I did test the piston before tightening the mounting plate, piston  
returned fine. The valves seemed to be fine, but I don't know how to  
gauge if they are operating correctly.  I suppose I need to take the  
servo apart again and see if anything is amiss.



On Oct 22, 2006, at 7:44 PM, S Manwell wrote:

> Peter,
>
> Did you test the big vacuum piston to see that it moves freely in  
> the cylinder?  You should be able to push the piston in against the  
> big spring and the spring force should be enough to return the  
> piston when you release the pressure on it.
>
> The assembly of the valves on the side of the aluminum casting must  
> be right too -- when you release the brake pedal, the control  
> piston in the smaller cylinder should return, causing the valve to  
> close off atmospheric pressure and apply equal vacuum to both sides  
> of the big piston allowing the big spring to return it.
>
> I can't think what the O-rings would be for...
>
> --Steve
>
> peter king wrote:
>
>> A frustrating day on the Rover farm today. I rebuilt the P5 servo   
>> yesterday, and installed it today, but the brakes stuck on after   
>> starting the car. I removed the servo and re-aligned the piston,   
>> afraid that it was binding. After a second installation, the  
>> brakes  still stick.
>>
>> The vacuum line valve is operating properly (one-way), no fluid   
>> leaking past the seals into the vacuum chamber, so at least that   
>> problem is fixed, but what other problem should I look for? There   
>> were two small "O" rings in the rebuild kit which I could not  
>> find  any use for. Might I have left something out?
>>
>> Any thoughts would be greatly appreciated.
>>
>> Thanks,
>>
>> Peter
>>
>>
>>
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>
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