Lotus Elan

Servo - working or not

PostPost by: hansaxl » Fri Jan 04, 2013 10:46 am

Hi everyone,

my S4/Sprint still has the servo fitted. However, I doubt that it works, as the pedal force is quite high, even with soft compound brake pads, and there is no feel whatsoever of the servo "coming in", which had been bery pronounced on the Plus 2 I drove before.

So, is it possible at all to have a dysfunctional servo and at the same time brakes that perform as if there was no servo at all?

I think I could test this by disconnecting and plugging the vaccum hose, correct?

If it does not work, I will probably get rid of it. On the other hand, here we have a typical case where originality and layiness form a very nice combination, don't you agree?

Thanks for your comments,

Cheers,

Hans
'70 S4/Sprint
hansaxl
First Gear
First Gear
 
Posts: 49
Joined: 30 Jan 2010
Location: Germany

PostPost by: Quart Meg Miles » Fri Jan 04, 2013 11:13 am

Yes, yes & yes. What were the questions?

My S130 servo filled with fluid and the brakes were simply heavier but perfectly driveable so the lighter S4 should be fine without it. In fact, because the car was so over-servoed (at about 3:1) and the clutch so heavy I seriously considered moving the servo to the clutch. The vacuum is the power source for the servo so disconnecting it eliminates any servo action. I don't recall a servo delay on my car and I was still driving the S2 at the time.

Originality is in the eye of the beholder! As yours already isn't, just messing about with the brake servo shouldn't offend too many people but you can leave the defunct unit in place, complete with pipes, to create the illusion of originality.
Meg

26/4088 1965 S1½ Old and scruffy but in perfect working order; the car too.
________________Put your money where your mouse is, click on "Support LotusElan.net" below.
User avatar
Quart Meg Miles
Fourth Gear
Fourth Gear
 
Posts: 984
Joined: 03 Oct 2012
Location: Barnham, W Sussex, UK

PostPost by: oldelanman » Fri Jan 04, 2013 11:22 am

Hi Hans,
There is a whole page in the Workshop Manual on how to test the brake servo and diagnose faults. If you don't have a manual let me know and I will see if I can scan the page and post it here.
Roger
S4 DHC
oldelanman
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1661
Joined: 02 Jan 2008
Location: Dorset UK

PostPost by: hansaxl » Fri Jan 04, 2013 1:28 pm

Thanks for your answers.

Well then, looks like a nice half day messing about with the brakes. Thanks for offering to scan the workshop manual, but this is not necessary. I got one, just did not think about it, as usual.

Cheers,

Hans
'70 S4/Sprint
hansaxl
First Gear
First Gear
 
Posts: 49
Joined: 30 Jan 2010
Location: Germany

PostPost by: UAB807F » Fri Jan 04, 2013 5:02 pm

Hi Hans,

The way I used to test mine before the annual MoT was to press the brake pedal several times without the engine running to remove any residual vacuum and get a hard pedal. Then start the engine whilst holding the pedal firmly down and you'd feel a slight give in the pedal if the servo was working. That's the way the garage checks them, or at least how they used to do it.

Brian
User avatar
UAB807F
Fourth Gear
Fourth Gear
 
Posts: 645
Joined: 20 Dec 2010
Location: Lincolnshire

Total Online:

Users browsing this forum: No registered users and 12 guests