Hi guys, 

 

You guys must be sick of my questions by now but I dont know where else to turn and you guys are the experts.

 

I have a Skoda Fabia Mk1 Combi - 

 

 

 

That is the link to the first topic explaining a few things that were wrong with it to begin with, most of which ironed out now, however new issue.

 

After replacing the brake calliper at the back I have drove well over 1000 miles and (I believe probably unrelated) I have now ran into this problem: 

 

(As you guys will note from my last link, ABS Sensors have still not been swapped, will do them just before MOT)

 

As soon as I travel over 15 mph my hand brake warning light comes on flashing , 3 beeps heard from dash and light keeps flashing till I go below 15mph again

Unless, I drive for more than about 5 mins over 15mph, in which case the light continues flashing even after I slow down.

 

I have checked fluid, it is topped up plenty, I have been round all callipers and brake lines and cant see any obvious leaks, I have tried holding handbrake switch down manually, none of these have made a difference.

I do not believe it is the handbrake switch as the light goes off if I have just started the ignition and am stationary, its only as soon as I go over 15 mph the light comes back on.

 

As I have said before It is only if I drive over 15mph for a few mins that that light stays on and wont disappear after stopping, I just want to note, When it is in the stage where the light WILL go off when I stop, Each time I press the brake I can feel vibrating/juddering, as if a brake is sticking or ABS is kicking in or something...... Once the light is at the stage where it WONT go off, Brakes work perfectly fine......

 

Any Ideas guys? Both the back callipers are new and I have had a mechanic check it over, everything is 100% right as far as we can both see on that back, fronts dont seam to have any issues that are obvious... going to take them apart and put them back together soon to check everything is moving and lubed up like it should be, a little part of me thinks there's another seized brake.

 

@taylsy01 - Are both handbrake cables releasing fully when you release the handbrake?

Correct me if I am wrong, there are only 2 cables running to the back brakes? None to the front same as most cars?

I havent actually checked that to be honest mate

How would the computer know if that was the problem out of interest? I dont have brake pad wear sensors (As far as I know) only wheel speed sensor(or abs sensor, same thing) 

59 minutes ago, taylsy01 said:

How would the computer know if that was the problem out of interest? I dont have brake pad wear sensors (As far as I know) only wheel speed sensor(or abs sensor, same thing) 

 

It wouldn't.

 

Check the brake light switch.

Now brake light switch seams likely as I have wired up my tow bar without a bypass relay with connector blocks to my rear lights and was advised the switch will likely have a shortened length. How do I test it?

I thought you got a permanently on glowplug light and no brake lights with the brake light switch failure?

 

Anyway, check whether or not the brake lights come on!

Brake lights work fine, I thought it was glow plug light for that too but I could have been wrong new to Skoda.

 

Apart from these odd issues im having, The Fabia actually seams pretty good.

check the micro switch below the handbrake lever...

Brake light switch is a double pole switch, one pole for the lights and one for the ECU, the brake lights can work but the ECU doesn't know you're braking and vice versa.

1 hour ago, sepulchrave said:

Brake light switch is a double pole switch, one pole for the lights and one for the ECU, the brake lights can work but the ECU doesn't know you're braking and vice versa.

 

Are these easy to see the difference? That sounds like a possible cause

 

5 hours ago, fabdavrav said:

check the micro switch below the handbrake lever...

 

Played around with that. No difference. It seams to work fine. Turns the light off till I'm over 15 mph.

 

 

does anyone think it is possibly a warped disc?

1 hour ago, taylsy01 said:

 

Are these easy to see the difference? That sounds like a possible cause

 

 

Played around with that. No difference. It seams to work fine. Turns the light off till I'm over 15 mph.

 

 

does anyone think it is possibly a warped disc?

 

Best way to test the switch is simply to replace it, they're cheap but awkward to get at.

 

No chance it's a warped disc, how would the ECU know it was warped? No, this is an electrical fault.

I am hearing a slight rubbing noise when I am driving the last day. Part of me really does think it's mechanical.... I've got a mate who's gonna scan with VCDS today. Could a warped disc or abs ring not throw an error like this?

Have a good check of the wiring to the connector that plugs into the brake fluid reservoir (easier said than done, surely).

1 hour ago, Wino said:

Have a good check of the wiring to the connector that plugs into the brake fluid reservoir (easier said than done, surely).

 

I have checked the wiring, it seams ok... i have tried running with it disconnected and I get the same issue... 

Anyone think it would be worth disconnecting all of my ABS sensors? (God knows how i'll do it, I can't figure out the clip at all)

That way the only sensor left on my braking system (if im correct) is the fluid level....

2 minutes ago, taylsy01 said:

I have checked the wiring, it seams ok... i have tried running with it disconnected and I get the same issue... 

 

Try linking the two contacts of the loom plug with a piece of wire and see if that makes the problem go away. Unplugged would be the same as low-fluid, I think, so should give a warning.

Shorted would simulate OK fluid level.

Just now, Wino said:

 

Try linking the two contacts of the loom plug with a piece of wire and see if that makes the problem go away. Unplugged would be the same as low-fluid, I think, so should give a warning.

Shorted would simulate OK fluid level.

 

I had a mechanic mate who suggested this aswell, I dont remember if he tested it or not when we were having a look around it. Any thickness of wire do? 

 

Any old bit of wire that will poke in there.  Current will be tiny.

Got it scanned with VCDS. 2 rear abs sensors getting unexpected readings. Take it it's either sensors or rings. The reason I didn't get it from when it was only the 2 passenger sensors (front n rear)  is that one of them is completely gubbed 

Do you guys think this sounds plausible?

Wouldn't an ABS fault put the ABS warning light on instead?

Abs warning light has been on permenantly since I bought the car

1 hour ago, taylsy01 said:

Abs warning light has been on permenantly since I bought the car

 

Wow, now why the hell didn't you tell us that in the first place?

"(As you guys will note from my last link, ABS Sensors have still not been swapped, will do them just before MOT)"

 

And I gave a link to my very first post here, To be fair It wasn't that clear but I did note it lol

Typically to move on with problems, you really do need to sort out the things that you know are faulty first, you seem to be avoiding doing this, so not much chance of getting things becoming any better?