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brakes-or rather lack of

Posted: 10 Apr 2018, 08:21
by ermie571
Lost the brakes last night.
But have fluid in the reservoir

Some resistance engine off
Nothing engine on

ok - whats gone? Is the servo still working as it is assisting when the engine is running?

Handbrake light on - indicating low fluid.

But where is the sensor for the level....there is nothing in the top of the fluid reservoir - just a black screw on cap, no electrics :-)

Van at garage I trust - I'd just like to know the likely culprit :-)

Em
xx

Re: brakes-or rather lack of

Posted: 10 Apr 2018, 08:32
by Ian Hulley
ermie571 wrote: But where is the sensor for the level....there is nothing in the top of the fluid reservoir - just a black screw on cap, no electrics :-)

Hiya Emm, the normal T25 cap has a float switch built in and the 2 wires to a plug.


Image


The last time my brakes 'went' it was actually the clutch master cylinder that was peeing the fluid down onto the cab mat.

Ian

Re: brakes-or rather lack of

Posted: 10 Apr 2018, 08:50
by bigherb
Most likely the master cylinder has failed if there is still fluid in the reservoir.
If you have the three wire brake light switches the light is coming on due to the differential brake pressure in the master cylinder.

Re: brakes-or rather lack of

Posted: 10 Apr 2018, 08:59
by Titus A Duxass
bigherb wrote:Most likely the master cylinder has failed if there is still fluid in the reservoir.
If you have the three wire brake light switches the light is coming on due to the differential brake pressure in the master cylinder.

What Bigherb said. I have also experienced this (on the autobahn), I'm afraid master cylinder has gone kaput.
Not a major job for a qualified mechanic. But if you go to somewhere like quick fit they will start at the rear wheel slave cylinders and fault find their way foward and eventually end up at the master cylinder.

Re: brakes-or rather lack of

Posted: 10 Apr 2018, 09:02
by ermie571
Hi folks, thanks for this :-)

Ian- no electrics on mine - basic van from 1984. Just a screw cap. :?: No obvious lead hanging around either. Checked cab mat straight away - nothing obvious. But will ask garage to check again :-) thanks for the pointer


Titus/Bigherb - is the master cylinder you speak of the same one as Ian is talking about? Where is is please? I think we have changed one before but I can't remember. Oh - is it the one under the reservoir? if there is no fluid on the mat, can it fail without leaking fluid??

Interestingly, I thought that in the event of fluid loss, the clutch went before the breaks, but gear changes are fine.


I topped the level back up to max - (was just on minimum) and it didn't change on pumping the brakes, and was still on max when I looked at it an hour or so later.

I'll update with verdict from garage :-)

thanks both

E
x

Re: brakes-or rather lack of

Posted: 10 Apr 2018, 09:30
by Titus A Duxass
Emma - the master cylinder is under the instrument cover.
You have lost brakes due to the master cylinder failing, you do not have a fluid leak (the clutch would be the first to stop if you had leakage).

Wayne will sort it in no time.

Re: brakes-or rather lack of

Posted: 10 Apr 2018, 10:07
by bigherb
The master cylinder is what the reservoir is attached too.

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Re: brakes-or rather lack of

Posted: 10 Apr 2018, 10:15
by ermie571
Wonderful - thanks for the clarification!

I had just about got there :-)

Re: brakes-or rather lack of

Posted: 10 Apr 2018, 10:37
by bat
Seems there's more than one style of the reservoir, are they interchangeable or specific to the cylinder underneath (can't tell from my photo if the cylinder is the same)?

bigherb wrote:T
Image
Image

every day's a school day.

Regards Gary

Re: brakes-or rather lack of

Posted: 10 Apr 2018, 11:04
by bigherb
bat wrote:Seems there's more than one style of the reservoir, are they interchangeable or specific to the cylinder underneath (can't tell from my photo if the cylinder is the same)?

every day's a school day.

Regards Gary
Later vans had a wider reservoir and non servo brakes had a different one again.

Later resevoir.
Image

Re: brakes-or rather lack of

Posted: 10 Apr 2018, 11:14
by bat
Thanks for the info, No servo scary.
Regards Gary

Re: brakes-or rather lack of

Posted: 10 Apr 2018, 11:15
by Ian Hulley
https://www.brickwerks.co.uk/t3-parts/b ... er-t3.html

Image

I assume the float switch is just on the 'late' styleee.

Cheers, Ian.

Re: brakes-or rather lack of

Posted: 10 Apr 2018, 12:26
by bigherb
Ian Hulley wrote:
I assume the float switch is just on the 'late' styleee.

Cheers, Ian.
No they could be on early ones as well but rarer.