Brakes lights suddenly not working (master brake cyl. replaced)

[Windisch]

Just had the car's master cylinder replaced by my shop and after getting home I was advised that the brake lights weren't illuminating by a camp-follower (wifie). Fuses all appear to be fresh and functional. Seems likely that the fault lies with the brake light switch on the master cylinder. Does that seem a logical conclusion? Perhaps the blade electrical connectors on the switch were inadvertently left unconnected? Can't think of any other reasonable explanation.
_________________
1973 Standard Beetle, 1974 VW/Porsche 914-4, 1.8 liter
----------------------
Der Volkswagen ist ein Ausdruck der deutschen Kultur der Allrad Art ...

[The only irrefutable evidence we have that intelligent life truly exists elsewhere in the Universe is the fact that so far it has NOT contacted humanity...]

[raygreenwood]

[Windisch]

[Windisch]

I've gone through several 914 service/repair references I have and in Patrick Paternie's excellent HOW TO RESTORE AND MODIFY YOUR PORSCHE 914 AND 914-6, on page 90, mention is made of installing a LARGER 19mm Master Cylinder (to replace the 914-4's stock 17mm unit), such as is found on the 911 and 914-6. This larger bore cylinder is a substantial improvement over the small bore cylinder, according to Patrick.

This is the 'larger Master Cylinder' that was used on my car and indeed, the braking seems notably improved with the new cylinder installed. However, that still leaves the matter unresolved of the 'non-working' brake lights.

As near as I can determine, the two most likely possible culprit components are 1) the stop-light switch or 2) the connections that hook up to the cylinder itself. Checking under my car (the protective Master Cylinder plate seems to be missing) and pulling the rubber boot back from the connection in reference, it appears that my new cylinder has a single blade connection on the side of the connection's end portion...but I note two wires going into the wire container tube leading up to it (?). Glenn mentions that there are single and double wire connection cylinders, so whether this may be a problem source or not I am uncertain.

Still waiting for contact from my shop regarding bringing the car in to have this resolved...which seems passing strange, since the shop did not check to see that the brake lights were working after the cylinder replacement AND ya can't drive the car safely without functional stop lights! Grrr. Grrr.
_________________
1973 Standard Beetle, 1974 VW/Porsche 914-4, 1.8 liter
----------------------
Der Volkswagen ist ein Ausdruck der deutschen Kultur der Allrad Art ...

[The only irrefutable evidence we have that intelligent life truly exists elsewhere in the Universe is the fact that so far it has NOT contacted humanity...]

[raygreenwood]

[Windisch]

Hi Ray. Yup, my car has the mechanical switch, so earlier today I assumed the contortionist posture, scrunched down into the footwell, pulled up the pedal assembly floor-panel, and tried to adjust the switch. The Brooklands 914 tech/shop manual has the procedure pretty well explained and illustrated ("Insert a 4mm thick piece of metal between the pedal contact and the pedal stop, then loosen the adjusting screw's locknut so that the adjusting screw may be set at the right position to trip the stoplights with minimal pressure"). All well and good, except that I lack the needed angled 15mm wrench that is required to loosen the locknut, Hence, I'm basically dead-in-the-water in terms be being able to make the needed adjustment myself. Bummer and a half!

Sooo...I'm back to waiting for a call from the shop to let me know if and when they can adjust the switch for me. I should hear something from them tomorrow (Monday after Easter) about this. Hopefully this will be squared away ASAP, since the shop clearly failed to observe the final step involved in trading out the old (17mm) cylinder for the new (19mm) one:"CHECK TO BE SURE THE STOPLIGHTS FUNCTION NORMALLY!"

_________________
1973 Standard Beetle, 1974 VW/Porsche 914-4, 1.8 liter
----------------------
Der Volkswagen ist ein Ausdruck der deutschen Kultur der Allrad Art ...

[The only irrefutable evidence we have that intelligent life truly exists elsewhere in the Universe is the fact that so far it has NOT contacted humanity...]

[Windisch]

An update on this little problem (that is likely very inconsequential to most old 'Porsche hands'). As I mentioned earlier, I was unable to make this minor but very important adjustment to my brake pedal's stoplight switch due to lacking an angled 15 mm wrench to get the adjuster screw's locknut loosened. As well as I can determine, one needs to either have a whole set of angled-head metric wrenches in one's tool chest already or go down to the nearest auto parts store and buy the specified sized wrench to resolve this matter (which is probably somewhat expensive and likely to be used only once in a very long while).

Since I have enough of a Scot lurking in my DNA, I'm a bit like the Scot who has had a wee bit too much to drink and is standing in front of a 'pay-to-use' toilet at the Highland Games, squirming with discomfort due to being just not quite fully convinced of the need to part with a required coin! (Apologies to our Scots friends across the pond!). [Of course, a real Highlander would probably skip the formal niceties and just let fly in the grass, nearby, but...]

Fortunately, my shop called me this AM and said they could take me back this Wednesday (day after tomorrow) and do the adjustment or me, but I am again reminded of the fact that when one has German air-suckers in one's stable (whether Porsches or VW Bugs), a few special tools are absolutely mandatory to have handy in one's tool chest. And like work on Italian cars, it also helps to be a contortionist with smaller-than-usual hands, LoL.

As a parting comment, I have amassed a huge collection of Porsche/VW 914-specific technical references in my library but I have found, perhaps not too surprisingly, that no single book or manual has EVERYTHING one may need in it to get a certain job done properly on one's car. There always seems to be one book in particular among them that covers a needed repair or service more completely and/or in greater detail than the others. Furthermore, the fact that each reference doesn't uniformly index specific subjects exactly the same way often means that you can't depend upon turning to a book's end-index pages to quickly find the subject you are searching for. I've also often been both surprised and mildly flummoxed to find that what one book may cover in some detail (with great images/diagrams, etc.) may be almost totally missing (or lightly breezed over) in the other books. That said, and despite the fact that a number of excellent references have already been written on both VW tech matters and Porsche-specific ones, there's still room for another attempt to write and publish a 'compleat' (sic), master service and repair manual for 914 owners.

I say this as a shade-tree mechanic with only marginal skills, of course, since I often need a bit more hand-holding when tackling what more skilled and accomplished amateur mechanics would consider kindergarten-level repairs. Still, as an equally ardent bibliophile, I keep hoping for that 'ultimate, supreme 914 service and repair manual' to come along, some day! [Of interest is the fact that back in my work in Cardiac Surgery suites (as a perfusionist), I was the same way...always seeking out supportive cardiovascular peer involvement, LoL! The more minds bearing on critical problems, the better the chances of resolving them!]
_________________
1973 Standard Beetle, 1974 VW/Porsche 914-4, 1.8 liter
----------------------
Der Volkswagen ist ein Ausdruck der deutschen Kultur der Allrad Art ...

[The only irrefutable evidence we have that intelligent life truly exists elsewhere in the Universe is the fact that so far it has NOT contacted humanity...]

[[email protected]]

the master cylinder warning switch has nothing to do with the operation of the brake lights, it is the switch on the pedal cluster under the wooden floor board. They probably dislodged the plastic brake light switch finger when they removed the master cylinder

[Windisch]

[Windisch]

Just got the car back from the shop this AM, where the stoplight problem seems to have been resolved. I was told by the mechanic that "...the little arm that actuates the (stoplight) switch was not properly aligned on the switch and a little fiddling with it got it back operating properly."

That said, it seems slightly improbable that VW/Porsche would have designed and engineered a stoplight switch actuation that COULD get 'out of proper alignment' in the first place" but there it is. I suspect that they did not carry out the resolving procedure outlined in the Brooklands procedure that I highlighted above but since I wasn't there watching over anyone's shoulder, that's the impression I received from my mechanic.

They also found a bad bulb in the right rear taillight structure, but whether that had any additional effect, I am uncertain.

Next problems to deal with concern a speedometer replacement cable and a new throttle (accelerator) cable, since both are in less than optimal operative condition. The speedo will be sent off for a rebuild and I'll just buy the new cables from Pelican or Auto Atlanta.

What next? My car ("Jezibel") seems to be full of surprises. My mechanic told me also that my dual-carb (Weber 40IDF) set-up probably included a mild performance cam added so as to work with the custom (Monza-type) exhaust system on the car. I sorta suspected the up-graded cam, since the car wants to scream in the higher RPMS and does a sort of 'rumpa-rumpa-rumpa' at idle. "Oh yeah! Your 1.8 engine is now probably putting out about 110 BHP, so there's no telling what other engine mods it may have had (like bore & stroke alternations, etc.)." Quote, unquote!
_________________
1973 Standard Beetle, 1974 VW/Porsche 914-4, 1.8 liter
----------------------
Der Volkswagen ist ein Ausdruck der deutschen Kultur der Allrad Art ...

[The only irrefutable evidence we have that intelligent life truly exists elsewhere in the Universe is the fact that so far it has NOT contacted humanity...]

[Windisch]