Subject: Re: LG45 brake servo
Hi Bill
No experience of fitting a brake servo to Girling mechanical brakes but I do have considerable experience with setting up the basic Girling system.
If properly set up. well lubricated and adjusted ,with the arc of the shoes matching the drums then these brakes should be pretty good without a servo.
I have run several cars other than Lagondas with the Girling system and have found that when set up correctly they were able to lock the wheels, the MOT was never a problem...
The brakes on my LG45 were "ok" but not so good as I thought they ought to be so as part of the ongoing restoration I took the brakes completely apart and refurbished them. The main difference between my LG45 and previous systems I have worked on is the relatively long flexible cables between the foot pedal and the axles which I believe were introduced at Sanction 3 to stop the foot pedal being effected by the axles going up and down over a bump. These cables were very stiff to operate due to congealed grease and were also frayed inside so I have replaced them with new cables made by "Speedy Cables" in Wales (who I found did a pretty good job). Freeing up or replacing the cables should make the pedal action much easier.
Also the mechanical actuators in the drums need stripping, cleaning and re-greasing regularly if they are to work as intended. The actuators must be able to slide on the back plate to allow the brake shoes to centralise in the drum. NB: The holes in the back plate are elongated to permit sliding movement and the studs which attach the actuators must be fitted with the original style double spring washers and castellated nut / split pin ...the nuts should not be done up too tight to allow the actuator to slide easily, so split pins are essential for safety to stop the nuts coming undone. (New dirt gaiters are a good idea too and are available from Club spares).
Inside the actuator is a cone attached to the end of the brake rod by a fulcrum pin and then there are two hardened steel rollers which ride up the cone to push the expander pistons outwards and apply the shoes to the drum. If the grease is congealed it makes the actuator stiff / inoperative. Frequently the fulcrum pin is found to be worn "D" shaped and / or the rollers have flats on them (so they skid rather than roll). These defects can cause a loss of movement and unbalanced /poor braking.
Recommend checking the area of brake shoe being rubbed too, which should be most of both shoes. If only one shoe is contacting properly then the actuator is likely to be the problem by not sliding and hence not allowing the shoes to centralise. If the shoes are only rubbing in the middle then they are too small for the drum and if only rubbing at the ends then they are too large and either way the arc of the linings need adjusting by linishing the lining to fit the drum.
If you would like to discuss I am happy to help if I can, my number is listed in the Club Register... But you maybe aware of all this and I am teaching grandmother to suck eggs, so if that is the case then I apologize in advance!
But the above may help someone so I offer it up anyway...
See also the description in the Club's Handbook for the 4.5 litre cars.
Best wishes
Bill Cooper
Search
Team
Important Tools
Misc. links Active topics... Newsfeeds (RSS, ...)
Log in
Printer friendly version
Show PDF file