Lotus Elan

Brake servo connections

PostPost by: cdraper » Mon Aug 03, 2009 12:19 pm

On an Elan +2 I have recently purchased the brakes tend to lock on. I have fitted a reconditioned Master cylinder and brake servo - but the problem still sometime occurs. Brakes can be released by loosening the pipe to the master cylinder to release the pressure. Odd as the master cylinder has the return valve in it and the fluid should go back to the resivoir. The pedal also sometime feels very hard and kicks back!. Looking at the servo connections - GIRLING - the pipe from the master cylinder connects to the rearmost port and the one to the wheels to the port next to the vaccum chamber. From the workshop manual this looks to be the wrong way round but would explain the problem. The drawing in the manual is rather small and it could be wrong. Before I change the pipes round could some kind member look at their car and tell me where the pipes ought to go.
:roll: :roll: :roll: :oops:
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PostPost by: rdssdi » Mon Aug 03, 2009 12:45 pm

I used Lockheed remote servos. For these servos the master cylinder feeds to the port on the side of the casting closest to the vacuum canister. The outlet to the brakes is at the very end of the casting furthest from the vacuum canister.

If you have installed the original Girling units I am not certain the layout is the same.

You might check if the vacuum return check valve is working or even there. It is attached to the end of the metal vacuum pipe that runs along the firewall. At least in my U.S. LHD car it is.

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PostPost by: TeeJay » Mon Aug 03, 2009 2:32 pm

On my 1968 +2, single Girling servo.
The pipes are connected as per the Manual, see detail below.

Also see the attached re the testing of the unit re the "brakes hanging on".

If you PM me your e-mail address I can forward you the Girling 9 page document.
Hope this helps.
Girling Hydralic Servo Unit 2.jpg and
Girling Servo Pipe Positions.jpg and
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PostPost by: barrydoran » Mon Aug 03, 2009 9:54 pm

Brakes locking on and pedal pushing back are well known symptoms of a failed Girling servo. Have a search around.


I speak from experience, mine failed in exactly the same way.

I was told that it can be caused by dirt in the fluid stopping some internal ball bearing seating properly.

So try bleeding with plenty of fluid throught the servo.

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PostPost by: cdraper » Tue Aug 04, 2009 10:53 am

Thanks guys - clearly my servo is connected the wrong way - with th pipe from the master cylinder fixed to the rear port and the one to the brakes next to the vaccum chamber! Have no idea who did this or why - when I fitted a reconditined servo I just connected it up the same way.
Does anybody else know caes like this?
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PostPost by: handi_andi » Tue Aug 04, 2009 8:58 pm

I had a brake locking on problem for a while and turned out to be the remote servo. Spot to Classic Brake Company about it and turns out it is a common problem on the remote servo with the little hydraulic piston sticking. Simply solution was to pop the piston out using brake pressure, clean the bore very carefully with a bit of emery paper and a rod. Clean up piston, reassemble, bleed brakes, and bobs your uncle problem solved and brakes better than normal.

Could be the same issue...

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