Today, I have mixed messages, and need advice! My 1996 4litre Sovereign passed its annual MOT test but with some advisories! The strangest is that the inspector did NOT find a low brake fluid level, NOR any fluid leaks but the low brake fluid warning light is on! This suggests to me that I have electrical gremlins somewhere. Do any of you knowledgeable people any pointers?

 

I wasn't aware there was a low brake fluid light!
Same one that comes on when you apply the hand-brake? If so, I'd check the switch at the handbrake

 

No it's not the same as the parking brake, there is a separate light.

The switch for the light is in the side of the brake fluid reservoir, with a two pin plug attached. It's a very simple on/off switch (NC - Normally closed). Pull the plug and do some tests

1. Test continuity across the switch - you should have continuity in normal condition.

2. You can further test by shorting the pins in the loom connector - does the light go off? If so the wiring from the plug to instrument panel is good.


I should also add that it takes the warning light/message a few seconds to set/reset when the testing so be aware of that.

 

Why not remove brake fluid cap and see if the fluid is low? Excuse me, but why would you go looking for other problems until you have done that? Check Occum's razor on Google.

 

OP indicated that they already checked for low fluid and any leaks.





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No, not as I read as I read what he said. He said it passed the MOT. Not that someone checked the fluid level specifically.
Was the light on when the inspector passed it?

 

I dunno, Ross,
I read it as; Inspector saw the light, then went looking for low fluid level and/or a leak, finding neither.

 

It's part of the MOT test to check the Brake Fluid level (where the reservoir is transparent) - regardless of whether there is a warning light or not. Low fluid level would be a fail.

So we can assume the fluid level has been confirmed as good.

 

Ok, well then Brendan's test is obviously the next step. I dunnoh about what a MOT inspector does, but I would have hoped he would be in a position to make such a test himself. (Obviously for an additional fee)

 

I'm not sure this will add much, but the MoT examiner is primarily concerned with the operation of the brakes, the absence of warning lights and the absence of visible leaks at the time of the test. There isn't much between a light off amount of fluid and a light on amount, and I would not be inclined to take any risks by making any assumptions about what an MoT examiner may or may not have done. Absent a definite fault in the level sensor, you need to approach this as a leak.

 

I guess we are only speculationg as to what the examiner did or did not check, what he did or did not say,and what did or did not cause a leak. So, I am back to CHECK THE LEVEL!

 

Many thanks for the responses. The car had passed its MOT test. There were no fluid leaks and the reservoir was full to the max mark. But the brake warning light and the message box indicated "Fluid" - which the handbook says is low fluid. So I suspected an electrical gremlin. At Brendan's suggestion I went looking for the switch hidden away under the plastics trim. The connector was not fully seated!! So, I pushed it fully home, the light extinguished and all is now OK. MANY THANKS.

 

Thanks for the update! Glad you got it fixed.