Remote Brake Servo

[scarrington]

Hi All, I have recently bought a 1970 1,000 van with an inline Lockheed remote servo that doesn't seem to work very well. I have changed all shoes and wheel cylinders, but I am not sure if there is a special way to bleed the servo cylinder, or if it has been fitted properly.
Does anyone have a copy of the fitting/bleeding instructions for such a thing? or can anyone tell me what the problem may be. Cheers Simon

[bmcecosse]

With drum brakes - you don't need a servo - more trouble than it is worth, as you are finding out! I would just take it out of the circuit - the drum brakes (in good working order) will be fine.
If you must continue with servo - it should be installed 'nose up' - otherwise it just bleeds through as normal.

[matchlessg3]

Hi, I fitted a servo sometime ago whilst fitting a 1275 midget engine. However because of experiences of oil leaks due to crankcase pressure I only used the car a few times. Now having stopped the oil leaks I took the car out on the Merseyside Branch Easter run and was really having to put pressure on the pedal to make it stop. I found on google an explanation of how the servo works with full diagrams. Mine was fitted with a non return valve where the pipe from the manifold goes into the servo, according to the diagrams this valve is not shown and on removing it I now have good brakes. In fact just taking the valve out and sucking on it closed the valve. It would seem that it has never worked since I fitted it. Hope this helps, Alan.

[bmcecosse]

The valve has been in wrong way round......try it the other way. It' s designed to hold a 'reservoir' of vacuum for you......

[matchlessg3]

Hi, Sorry for the late reply as I have been away at a jazz festival in Keswick. The valve will will not turn round and according to the diagrams I obtained from google (6 pages) which explains how the system works, it shows that a non return valve is not fitted. I was out in the car yesterday and the brakes were excellent, so I am quite happy to leave things as they are. However many thanks for your interest. Alan.

[bmcecosse]

It really should have a non-return valve fitted. Google isn't everything! You won't have any 'reservoir' of assisted braking if the engine cuts out for example. But as long as the engine is sucking air - it will of course work perfectly well.

[IslipMinor]

Hi Simon,

The link below gives you the complete AP Lockheed (now Delphi) installation manual for their remote servos. Interestingly it says that the separate in-line non-return valve is only 'advisable' on high performance cars, because there is a in-built non-return valve in the plastic connector for the vacuum hose.

I did not know this when I fitted ours, so spent good money on the separate in-line valve - I know, should have read the manual first!

http://gentry.zxq.net/Remote_Servo_Installation.pdf

[bmcecosse]

I'm assuming it was the non-return in the hose that was fitted wrong way round. Surely just a matter of turning the hose round ??