Servo Non-Return Valve

[William2]

I fitted a new Lockheed copy brake servo and sourced a non return valve off Ebay which I fitted in-line with the servo rubber hose teed off from the manifold (as shown in photo). The servo works very well but I have noticed that when I start a journey the brakes stick on briefly after initial braking but are fine from then on. I assume the non return valve I fitted is suitable as there is an alternative type that screws straight on to the brass manifold adaptor. Does my installation look ok from the photo (the valve is about 6" down from the manifold) and is it likely that the sticking brakes is a valve problem or something else? Has anyone had a similar problem?

[billwill]

I don't think your position makes any difference, but if that arrow on the valve shows the direction of air flow, then it is the wrong way around.

The engine is supposed to suck the air from the reservoir in the front member, not vice versa.

[William2]

Hi Bill, the headlights seem to work ok but I could try reversing that valve. Regards, William

[Orsom Weels]

I seem to remember there has been some chat about these replacement copy servos on here in the past, but the search function has let me down again & the only thread I can find is this one,

lotus-suspension-f42/yet-another-brake-servo-question-t15866.html.

<Edit> Just found another thread using google

lotus-suspension-f42/powertune-servo-t34503.html

I've had no experience of them first hand, however, I have heard a lot of complaints from other classic motoring circles & a quick google search threw up several reports of poor assembly &/or build quality. Here are just a few

http://www.mg-cars.net/mgb-technical-bb ... 611357.htm

http://www.tr-register.co.uk/forums/ind ... -problems/

http://www.nsra.org.uk/newforum/showthr ... mote-servo

It seems brakes holding on is not an uncommon problem & can be caused simply by the incorrect orientation of the servo unit, or by a fault in the assembly/manufacture. It's probably worth doing a bit of research to find out what others have done to get round the problems.

Regards, Tim

[LorraineLH]

Interesting....in the past few weeks Mini Cooper Register members have also complained about these Lockheed replica servos and have recommended to others that they "buy Bosch".

[Robbie693]

There is supposed to be a spring under the air cap which has been missing on lockheed servos for years, the spring stops the brakes sticking on!

See page 3 in attached:

[chrisbeck]

I realise this is an old thread but I'd like to thank all the contributors for their advice. I've had sticky brakes for a while and this info led me to remove the air filter cap and free up the air relief seat and apply a little silicon grease which has fixed the problem. To be honest, I'd always assumed that a replacement servo had been fitted during the re-build but it appears to be original.
Thanks guys,
Chris

[chrisbeck]

Hi Bill, the headlights seem to work ok but I could try reversing that valve. Regards, William

On my Elan the small check valve is mounted close to the servo, not sure if that would make any difference.
The brass valve is connected to the vacuum chamber for the lights and according to my copy of the Brian Buckland manual the arrow points opposite to the flow so yours is correct, hence your lights work! My car is the same.
Chris