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trying to bleed brakes on 68 bettle
bug060 - March 19th, 2006 at 07:46 PM

i just put a new master cylinder in and i got disc brake front end i can bleed it but cant seem to get the switch to work every thing is brand new there is power going to the switch but lights dont work i think there might be air there i dont know how to bleed it out ,,thankyou for your help :-)


jonnyb - March 19th, 2006 at 08:06 PM

my problem is the opposite once pressed the taillights stay on so i can't offer any help


hellbugged - March 19th, 2006 at 08:17 PM

make sure there is not a problem with the lights themselves by touching the two wires together- do they come on?


bug060 - March 19th, 2006 at 08:20 PM

the lights do come on when i put the two wires together :-(


hellbugged - March 19th, 2006 at 08:21 PM

Quote:
Originally posted by jonnyb
my problem is the opposite once pressed the taillights stay on so i can't offer any help


have you got any free travel in the peddle? the rod between the peddle shaft and actual master cylinder is adjustable, and should have a poofteenth of free travel.

there is also a plate on the floor with a small lip that stops the return travel for the peddle, this is also adjustable and can be used to align the clutch and brake peddles "starting" points, maybe you diont have enough return travel to get the master back to its "off" position?


hellbugged - March 19th, 2006 at 08:23 PM

Quote:
Originally posted by bug060
the lights do come on when i put the two wires together :-(


this might be offensive, but there can be two bleeding nipples on the calipers so they can be fitted to both sides of the car.

are you bleeding from the top nipple-thats where the air will be.


bug060 - March 19th, 2006 at 08:31 PM

i got the sherman disc brake conversion and they are pbr ones and there is only one nipple , when i take the rod out between the peddle and master the brake fluid runs out then when i put it back in it takes forever to bleed, i tryed adjusting it when i adjust it in it bleeds good but when i take it for a run no brake , and when i adjust it out its hard to bleed but good brakes when i go for a run, but i cant seem to get the switch to work, i have replace it with a new one from mick motors that is the master and the switch please help ?


hellbugged - March 19th, 2006 at 09:11 PM

i found in the past, with air locks, the lights would still come on, but need a lot of pressure, until i got All the air out. is this the case, or none at all?

still got the old switch?

if it was working try putting it back in there

while you have the new one out, give it a good blow with air,


Joel - March 19th, 2006 at 09:30 PM

is your car defiantely a 68?
the 1500s from 68 to /12/70 had disc brakes standard
is your master cylinder single circut (all the brake lines come out of the same area)
if its dual circuit the back brakes line will come out the middle and the front out of the front of the m/c
i think the original dual circuit m/c had 2 brake light switches but all the replacement ones i;ve seen only have one on the front brake circuit

hth
Joel


bug060 - March 19th, 2006 at 09:58 PM

yes i have tryed the old switch and still no go , i have not tryed blowing it yet, but i got i dual master which i got the lines from the fire wall are back brakes the middle line is drivers side front, and the end is passenger front and under that is the switch , i hope i got that right thats how the old master was set up as and thankyou so far with the help guys :-)


hellbugged - March 19th, 2006 at 10:07 PM

poor contact with the terminals?

give em a good clean


Joel - March 19th, 2006 at 11:45 PM

in all of my beetles the horn ran off the same wiring as the brake lights does your horn work as well?
the wiring on its way to the brake lights usually runs through a couple of those push together connectors maybe one of them has come apart

Joel


firefly - March 21st, 2006 at 12:54 PM

Ok, while I know nothing about these here is some things to check look at. I had an issue with my wife's beelte with brake lights. first thing to do is check that the switch is working. get someone to press on the brake pedal and see whether it goes from open to closed (multimeter on resistance setting) if it does then it is switching correctly. Make sure it goes off as well when teh pedal is released. Once this is functioning or you know it to be doing the right thing then turn your attention to voltage etc.

Meter the voltage on etc side of the switch. one should be nothing the other 12V if you have this then it is a good start. now press teh brake again. if both go to 0v then your issue lies in a connection thing or fuse box. If both go 12v and still not lights then the issue is between the lights and the switch (ie no ground or corrosive area).

I cannot remember where the brake light switch sits in the master. However, in most other cars where there is a switch in the master you need to bleed both the front circuit and the back circuit as well as bleeding the master properly. The way most switches work is when the pressure in both circuits are balanced. if you just bleed the front then you might find there is still pressure in the rear circuit when in rest position. this can do one of two thing. either A. not give enough pressure for teh switch to work, or B keep pressure in the master thus allowing the switch to be permanently on. So look and bleed everything.

I do have book at home which will allow me to understand the beetle setup more so but do nto have access now. see how you go.

Cheers


bug060 - March 22nd, 2006 at 05:53 PM

thankyou for this help i got a new switch again still nothing i think it might be just not enough pressure there yet i just have to keep bleeding it , i got other advice to i needed to have some pedal play as well so i tryed that still nothing at the lights , its just weird everything was working with the old one all it was wrong with it it wouldnt bleeed the front but the back it did , i might put the old one in again and give it a go , so anymore susjections please help thankyou :-)