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Hydraulic brake level switch sensitivity
bi22le - 20/5/12 at 02:49 PM

Hi all.

I mentioned this in another post but did not get much help so thought I would put up a new topic.

On my striker the brake lights use a hydraulic switch which is on the rear line. The press needed on the pedal to operate the lights is more than spirited driving so I have concerns with the people behind me.

I have bled the switch by undoing it, putting press of the pedal until it leaks then tightening back up. This has not changed anything.

Can I get a more sensitive switch or is it just a case of putting it on the front due to brake bias pressures?

Cheers

Biz

macc man - 20/5/12 at 02:57 PM

Sounds like a faulty switch. It should not take much pressure to operate. Mine is at the rear and works with little preesure.

jacko - 20/5/12 at 03:23 PM

I had the same problem and was told a VW brake switch was the best to use , I did not go down this route .
And I fitted a micro switch to the peddle / bulkhead it is the best way in my mind
Jacko

lewis - 20/5/12 at 04:19 PM

Would def be better in front of the system ( fwd of any brake bias)

coozer - 20/5/12 at 04:49 PM

OEM VW brake switch.. Eurocarparts, PN 464550020 £5.45 Its made by FAE.

big_wasa - 20/5/12 at 04:54 PM

On the front brakes is best.

ryanill - 20/5/12 at 07:06 PM

I too use a micro switch on the pedal. As soon as the pedal moves the lights come on

coozer - 20/5/12 at 07:21 PM

quote:
Originally posted by ryanill
I too use a micro switch on the pedal. As soon as the pedal moves the lights come on


Any pics? Is it a floor pedal? I fancy doing it myself.....

I predict a Riot - 20/5/12 at 07:28 PM

The problem isn't with your switch, it's your bias bar.

Under light brake loading the rear system isn't getting used.

Move the switch to the front system or preferably fit a switch to act directly off of the pedal.

mad-butcher - 21/5/12 at 10:08 AM

as said in various posts it needs to be mounted with the wiring pins at the bottom so any air will rise

bi22le - 22/5/12 at 09:51 AM

quote:
Originally posted by mad-butcher
as said in various posts it needs to be mounted with the wiring pins at the bottom so any air will rise


Personally i disagree with this.

I think that if the switch is at the highest point with terminals up then its easy to bleed and check that there is no air at the switch. Also saves adding an extra bleed valve. Also grantees that there is no air at the switch.

Would a faulty switch present as not sensitive? I would of thought that it just would not work. Also is the VW more sensitive than the average switch?

Cheers

Biz

daviep - 22/5/12 at 10:34 AM

quote:
Originally posted by bi22le
quote:
Originally posted by mad-butcher
as said in various posts it needs to be mounted with the wiring pins at the bottom so any air will rise


Personally i disagree with this.

I think that if the switch is at the highest point with terminals up then its easy to bleed and check that there is no air at the switch. Also saves adding an extra bleed valve. Also grantees that there is no air at the switch.

Would a faulty switch present as not sensitive? I would of thought that it just would not work. Also is the VW more sensitive than the average switch?

Cheers

Biz


Sorry but I think you have the wrong end of the stick with regards how a brake system bleeds.

If you mount the the switch with terminals up it is impossible to remove air which is trapped inside the switch, by loosening the switch you are trying to bleed at the lowest point when all air is at the highest point.

If you mount the switch terminals down the the fuid will naturally flow down in to the swich and displace the air into the pipe where it will pushed in to a caliper / wheel cylinder and be bled out normally, there is no need for any extra bleed points. I always give the switch a light tap with a spanner just to make sure any small bubbles rise up into the pipe.

I'm using a VW master cylinder which has the switches screwed in to the MC as standard - termminals are downwards

Cheers
Davie

bi22le - 6/8/12 at 06:12 PM

Either way I have fixed it now, new switch!!

I have updated this for reference. Future searching fountain of knowledge and all that jazz.

The brake light switch was faulty and replacing it with a new switch from Eurocar parts FAE 464550020.

Biz