TECHNICAL ASSISTANCE, DISC E-BRAKE DRAGGING

You don’t always need residual valves with disc brakes. Sorry for any confusion. I meant they may have left residual valves in for drum brakes when doing a disc brake conversion and this would keep a reasonable amount of pressure in the lines to overcome the springs on drums. But with no return spring on discs it ends up pushing the pads on to the disc. Disc brake residual valves operate at a much lower pressure.

I would check there’s free play in the brake pedal and the return spring is there.

 

I finally cleared my lift and the dune buggy is up in the air. I pushed it in so I could lift the car and rotate each tire, they all moved with ease. I lowered the car, pumped the pedal and put it back up in the air. The fronts moved, the rears did not. Tomorrow the pressure will bleed back off, weird.

The M/C on the car is ancient, one circuit, one brake light switch located in the nose of the M/C and a remote reservoir. The new one from JBugs is dual circuit and designed for use with their 4 wheel disc brakes which I have. They said it does not require residual valves.

I am wondering about the routing of the rear brake line. It is not under the car so it must be inside the vehicle. I see it exiting the storage area behind the seats, going to a splitter and to the individual rear brakes. Where is that line routed in a 76 beetle? When I changed the seats could I have pinched that line causing a restriction? I do not recall seeing a brake line when the seats were out.

Anyone know?

 

The line runs down the top of pan along the tunnel on the drivers side.

 

Some of it is exposed, I can see it move around the pedals and up the tunnel, then I can see a section as it runs next to the seat. Under the car I can see it come out of the body and into a splitter for the rears.

Last night i removed the M/C and even with a pry bar, I couldn't move the rear rotors. I unthreaded the brake hoses and they turn freely. Hardly any brake fluid came out, just a drip or two. Strange. I definitely have a hard stop on that rear brake line. Either a clog or it got damaged somehow. It isn't crushed on the outside of the body so I will take out the seat on the left side and inspect. I can always replace the hard line to the rears, I want to replace the fronts anyway, the PO or whoever built this thing used what they had form the beetle evidently. The lines are long and coiled around all over the place. Sloppy, I hate sloppy.

And why the hell did VWs use two brake light switches? The guy at JBugs said because there are two taillights. Okkkkaaaayyy. I either need two or a block off for one of the ports.

 

The JBugs website has a diagram that shows the routing and stock parts. I would suspect the rubber flex hoses in the rear. I have never seen a metal line let fluid flow only one way...

 

You were correct. I removed both rear hoses and I cannot blow air through them. They look original, as did the clips. New parts coming over night.

 

Good to hear you found the problem.

 

Thanks for your help. The new M/C will help as will the flush and fill with new fluid. Rod Run is a few weeks away and this is the car I want to take to the beach.

 

I bought new rubber hoses for the rear and installed the new dual circuit M/C. Whilst re-connecting the hard lines to the master the rear one broke off in my hands. I guess it was a bit corroded? The line broke off several more times removing it from the dune buggy. A new line has been ordered form Jbugs as I do not own a bubble flaring tool and the line was pretty cheap with the ends already on it. It will be here tomorrow. That coiled bit in the pic was from when the PO abbreviated the floor pan for the dune buggy? He simply wound it around in a circle and reconnected it to the rear tee.
I do not like the positive camber on the rear end. it is the result of adding coil overs to increase ride height and my misunderstanding of how the swing arm works on a beetle. If you do not know, the lower you go the more negative camber and the adverse is also true. As evidenced below

I can give a little height so I have ordered a pair of Hi-Jackers (DB Cooper version) that I can adjust to obtain a more agreeable rear camber without getting too close to the gl*** body. If I had IRS, this would have been a mere adjustment or shim job. Swing arms...welcome to VW 101.

 

Here's a good tip. If you are replacing the hard line to the rear brakes and don't own a German bubble flair tool (like me), you can purchase the 85" long line from JBugs (NiCop with flairs and fittings). My dune buggy is shortened wheelbase, so running the rear hard line through the body results in several inches of superfluous tubing. I did not want to run the line through the body as I plan to de-body mine in the near future (to replace the gas tank and sending unit in my one-piece body) and I didn't want to mess with that brake line when I did. I received the 85" line today, threaded one end into the br*** tee at the rear end and then ran it over to the left side of the car (like any hot rod build) and up the pan into the new dual circuit master cylinder. It fit perfectly, like it was made for this application. A few clamps to secure it from movement, well above the side pods I painted earlier this year with USA flag motif. Done and done. Now. onto the rear positive camber.

 

My Gabriel Hi-Jackers showed up today, felt like I was 17 again. I put on some Zep and knocked off the EMPI coil overs that were lifting the rear end too high causing the positive camber. I am hoping that I can find a happy medium (gay fortune teller) in ride height vs camber. 17-year-old me would have been proud (and confused) by the installation. Being an off-road vehicle (and having to p*** that engine and exhaust in the rear), I shielded the plastic line with stainless steel covers that I had left over from doing my daughters KC Hi-Lighters on her roll bar last year.

I built a cool little plate from stainless angle that is for sheetrock edge protection in commercial buildings. Just stuff I had lying about so there is no cost involved. I used the 3 carriage bolts that secure the remote oil filter and fashioned a sweet little bracket for the air valve.

Just big enough for the air valve warning plate, this is directly below the license plate in the rear of the dune buggy. I ordered one of those stainless-steel zip tie guns, it showed up this evening. I will use that tomorrow to secure the airlines, neat and tidy. My younger self would have stuck that valve in the license plate and taped the plastic hose to anything under the car I could find that didn't get hot. The game hasn't changed, the technique has improved.

 

Good work.
Marcus...

 

Lines ran and shielded. I had one long piece I cut in half then I sectioned in shorter pieces that I had from KC and used shrink wrap to hide the seam. Off road air shocks.

 

I put it on the ground today and drive it around the subdivision, tires are standing up better with 75 psi.

I’m thinking 65 psi will be about right. But I can live with this.

Brakes bleed, but no brake lights. I tested and there is no power to the brake switch. I used a spare battery, jumped power to the switch and made them work. So, not the switch, not the bulb. All fuses are fine. I suspect the turn signal switch. It is a United product with the blinking light in the stalk. Decent unit. I’ll tear into it tomorrow and see if I can find the power interruption.

any other ideas?

 

I am no bug expert. I gave away my For Idiots book to a kid that had bought one years ago.
IIRC, Ze Germans decided that for safety (?) to split the whole electrical lighting into two halves, left and right. Don't quote me on that, but expect it not to make sense until you have a WD in front of you then consider the mods on top.

 

Hah, just quoted you. The new M/C does have two brake switches in it. So, you may be correct.
I can't understand from the schematic I found how they routed the turn signals and brake switch.

There is a lot to digest there, but it looks like the last fuse on the right of the fuse box powers the headlights and stop lights. The fuse is good and the headlights work, no power to the brake switch would indicate to me an open in that line and easy to fix (other than cramming my body under the dash of a door less dune buggy. I figure I can just tap that fuse and route another lead to the switch and tape off that superfluous lead that has lost its power.

I have a United Pacific turn switch (the one with the blinky bit on the end of the stalk), this is the wiring instructions

I have two leads leaving one brake switch spade at 12 o'clock and a single lead on the other post, all of which are red. When I ran my test, I energized the post that had the single wire on it (sic o'clock). There is a 3rd spade at 9 o'clock on the switch (I'm only using one of the two switches on the M/C, I guess I have a spare to switch the wires to in case of an outage), according to my ohm meter the top and bottom spades complete the circuit when the brake pedal is depressed. The 9 o'clock post is weird; it has no connection when the pedal is down and completes the circuit when the pedal is raised? Was das fick? No matter, not using that one.

So, the spade on top with two leads leaving it is obviously heading to the turn switch according to the second diagram above and then on to the taillights like a standard wiring job.

Unless I am wrong, and I am never wrong, I should be fine tapping that far right circuit on the box as VW designed it and running a new wire to the brake switch. Einverstanden?

 

That worked! I ran a new lead from the panel to the brake switch and added an inline 15 amp fuse under the dash. I have brake lights, turn signals and the horn works again after cleaning off that aged Bosch unit. I cut off the old lead and wrapped it in case it ever wakes back up.

Tomorrow I will finish this project by removing the rear wheel bolts and replacing them with studs and acorns. I hate wheel bolts, heaven forbid you are roadside! Even on the lift they are a nightmare.

While I was at it, I replaced the valve cover gaskets with Felpro corks and suspecting the center bolts were bottoming out I put in studs and acorns. Looks like a hot rod guy had his hands all over a dune buggy, which of course he has!