Brake light coming on

craig r

craig r

Member
Hi everyone,

help needed please. I have noticed on my last couple of journeys in my 76 2200TC that the brake warning light starts to come on after around 30mins of driving.

The brakes themselves seem fine and the fluid reservoir is full. All other gauges on the dash read as they should.

The light seems to come on in the way I would expect an ignition warning light to come on. If I am taking away and I change from 1st to 2nd gear it gives a little flicker. If I am going uphill and the car is labouring a little it comes full on until the hill has been cleared.

There are a few leaks which need attended to, rocker cover, gearbox, oil pressure pipes, possibly rear rank case. so I know the car isnt running as well as it should. I also think the carbs arent at their best.

Could any of this cause the brake warning light to come on in this manner?


Thanks,


Craig.
 
Has anyone come up with a reliable was of refurbishing these? Not just the cork, but the whole thing. I took a couple apart recently and they were in a really horrid state, not worth trying to fix without new contacts/switches.
 
Thanks guys.

I thought it may have been a fault with the fluid level indicator but ruled it out as the light doesnt come on until ive been driving for a good 20/30 mins.

If it was a fault with the low level warning indicator would it not show up immediately I started driving?


Craig.
 
craig r said:
If it was a fault with the low level warning indicator would it not show up immediately I started driving?
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As you drive the level will vary as the fluid moves around under centrifugal(?) force, so that could affect it.

On the 2200 you only have the reservoir switch, the handbrake switch, and the wiring between them, the reservoir switch being the likeliest suspect. You could pull the Lucar connectors off the reservoir and see if it still does it, (don't let them earth out), and procceed from there.
 
I just wrote the following but Harvey beat me to it. :)
Orientation can make a difference. On mine, the reservoir tilts back slightly, so the sensor will think it's emptier when going up hill.
It's just a simple device - when the float is down, a brass disc drops to touch two contacts closing the circuit. You can temporarily remove the black, (earth) wire to take it out of the equation if you want to check that it really is the cause.
 
but in those first 20mins of driving i encountered circumstances and forces which would have caused it to come on, ie uphill and so on, if it was in fact a faulty level indicator. Im concerned why it doesnt appear straight away. Could fluid temperature/viscosity play a factor?
 
Maybe that when the car has been standing the top part of the float that's not under the fluid dries out, so it's more bouyant, then as you drive around the fluid sloshes around, soaking the top part, making it heavier, causing it to sink.
 
Cheers guys, thats been a great help. was really worried it was a larger problem but im fairly happy now its just a fault in the reservoir or with the connectors. I'll have a wee look at them next time im taking the car out. Probably disconnect them altogether to see what happens.

Ta :D
 
If you ever happen to be making good progress along a road and passengers ask you what that light is, don't tell them or they will panic.

I was on the Isle of Man going over the mountain course with two rear seat passengers who were less than happy with my blasé reply.

Oh that's nothing - it's only the brake warning light.
Click to expand...

If I was in a 40 year old car being driven in excess of the UK speed limit by a man I didn't know well, I don't suppose I'd have been too happy either.
 
had the car out again today and experienced the same issue. its becoming increasingly obvious that the light is coming on in the way an ignition light would come on. today, if i changed from 2nd to 3rd too soon and the car laboured slightly it would come on.

is there any way there could be a fault in the dashboard wiring causing the wrong light to come on?


Craig.
 
craig r said:
had the car out again today and experienced the same issue. its becoming increasingly obvious that the light is coming on in the way an ignition light would come on. today, if i changed from 2nd to 3rd too soon and the car laboured slightly it would come on.

is there any way there could be a fault in the dashboard wiring causing the wrong light to come on?


Craig.
Click to expand...
In your previous post you said you would disconnect the wires to the reservoir to see what happened. Was today's test done with this still disconnected?
 
No need for insulating tape - the black lead goes straight to earth so you can leave it loose without worrying about it shorting against anything.
 
any thoughts on the possible issue of a fault in the dashboard wiring? could the brake light be coming on when it should actually be the ignition light?
 
harveyp6 said:
On the 2200 you only have the reservoir switch, the handbrake switch, and the wiring between them.
Click to expand...
Just re-read this post from the beginning. Does this mean there are no pad sense wires on the 2200 Harvey? I only have access to diagrams for my 3500S so I know no different.

If so, then with the reservoir wire disconnected the light should not come on at all, unless the handbrake is applied, (which we know works in this instance), so if it still flickers then it is not a problem with the reservoir switch. Likewise, if the flickering goes away then it is the reservoir switch at fault.

If you disconnect both wires from the reservoir and connect them together, then the light should be on permanently.

The other culprit could be the handbrake switch itself, although I cannot see why it would only occur after a bit of driving, unless from heat build up from the exhaust??? Guessing here as I don't know the exhaust route in relation to the handbrake switch location. A similar test for the handbrake switch would be to remove the wires from the switch and see if the fault re-occurs. If not then it is the handbrake switch giving the fault.

I had exactly the same fault on mine, and it turned out to be the cork float in the reservoir. I made a new one, (after consuming the contents of the bottle it was attached to :shock: ), and it has been fine ever since.

With regards to your ignition light thoughts, does the 'real' ignition light work as you would expect when you start the vehicle? With the engine and handbrake off, do both lights come on and go out when you start the car? If not then I doubt there is a connection between them.
 
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