Aircooled VW South Africa

Haans wrote: ↑Mon Apr 05, 2021 9:51 pm Think you'll have to rethink his name,.......Stoffel Fritz MeFusco !
Haans

Maybe UN-MeFusco ...............



Not Undoing ... But ... United Nations



Herman

Herman,...did you get the PM,....not sure if this lot works. Have anothe PM sitting in outbox for couple of days and can't get it to move
Haans

JAa, Still waiting for reply from owner, will let you know when I hear something.

Sorry been pulling my hair out with brake fluid, so did forget to reply to your PM

Big Sorry SIR.

Herman

Duly noted ,....understand.
They say B-fluid makes your hair grow ?,...?let's wait and see if true
Regards Haans

So a quick update,

Have made space for the Booster & MC, and managed to fit it in under the bonnet.... Just

Also made adapter to join BMW shaft to VW peddles.

Have the correct free play, but as I need to make changes to the brake lines, testing has not been done yet.

Also can not fill with brake fluid as pipes have to be changed and re-fitted.

Will plumb in the Toyota Proportional valve to start off with, but may have to scrap it if we do not get it to work.

Still need to turn up and make a non-return valve for the vacuum hose as well as a 3 way connector to take vacuum from the carb balance line to the booster.

So a lot to do before knowing if this has been the solution to the problem.

Till later

Herman

Herman, I know you're building up to the grand reveal, but I'm having difficulty visualizing progress without pics.

73type2 wrote: ↑Thu Apr 08, 2021 12:46 pm Herman, I know you're building up to the grand reveal, but I'm having difficulty visualizing progress without pics.

Will see what I can do for you..

Herman

Just a short report on where we are today.

After we have fitted the Booster and MC into the smallest space possible vacated by the old VW Bus MC.

We spent time making up brake lines and fitting all the parts needed to make it work.

Due to the inclusion of the proportional valve we had a spider nest of pipes and connections.

On top of that the BMW MC did not have a placement for the Stop light switch, so yet another 3 way joint.

Having finally worked out the workings of the proportional valve we can now tell others how it works and how to connect it.

Filled the system with Brake Fluid and started pumping.

Had a number of leaks, but the positive was that it gave the air a place to get out fast.

had a hard peddle from the 3rd pump with out a bleeder open.

Got to tightened up the joints and stop the leaks,

Will not bleed the brakes till I have the vacuum line from the engine

Turned up the booster vacuum take off spigot, as well as the new non-return for the vacuum line.

Still have to turn up the 3 way connector for the vacuum line but that's tomorrows job.

Till then I leave you with the new setup so you can compare it to the old photo's earlier.

Herman

Did not give a Sunday update as we are still trying to get the brake system to where I feel comfortable.

Now you may ask, why the in-depth issue with the brakes, just fit them and get done.... well here goes..

Well there is an issue that is present in MeFusco, that is not an issue in VW single or double cabs.

The main problem is that in the VW you may have an empty load but you still have the motor and gear box out back,

This will in most cases prevent the back wheel dragging when brakes are applied, allowing a straight forward stop.

The MeFusco, has like zero weight on the back wheels and all the weight on the front,

so on braking, having disks all-round, the back wheels will lock up before the front has even started braking.

Should this happen it would be very easy to have the ass wip past the cab on braking.

This is where the proportional load sensing valve comes into play.

How it is supposed to work, is that the one half of the MC feeds the front brakes,

the 2nd half of the MC feeds the proportional valve inlet, and this is open to the feed back to the front wheels brake line linked to the 1st half of the MC,

The other port is to the back wheels. Now the valve is mainly closed to the back wheels when no load is on the back.

This brake fluid is directed to the front wheels as well giving twice as much pressure and volume allowing the front to do all or most of the braking.

When a full load is on the back, the valve opens fully to the back wheels and none is diverted to the front wheels,

In this case its as if the MC works like any other MC on most cars and VW with 1st half supplying the front and the 2nd half supplying the back.

So we could not get this stupid thing to work right and we where thinking we have the pipes incorrect.

Having tried all different ways we decided that as its new, it does not mean its perfect..... so

We went ahead and opened it.With all the parts laid out as they came out we could not work out how this could possibly work.

So finally decided to put my engineering hat on and re-assemble it the way I think it should be,

When done we tested it and Hey !! presto !!, it works......

It became clear that it must be a MONDAY assembled part as the spring was fitted in the incorrect place making it keep all ports closed.

So now to the final issue, as we have air bag suspension, the load will not regulate the ride height,

so the valve will not have a mechanical input to set the flow rate to the back wheels.

This we have overcome with a welded on set screw to set the percentage flow to the back wheels.

We may be able to find a happy setting for both full or empty loads, and per-set it there,

Or we will hand set it when load changes. this is only a few turns on a screw

OK so now you are up to date, and we can finalize the brakes this weekend.

Thanks for looking.

Herman

Horse and trailer setups use a separate lever for trailer brakes to get around that.

If your ex-Opel brakes have pulse generators for ABS brakes... Then maybe you could fit an ABS module and modulator. That should prevent the wheels from locking up.

Thanks Dawie,

Yes it did come to mind, but the front did not have sensor pickups, and the back did.

So I was thinking that Mefusco will not be a racing car and will not do a lot of miles per year, so it would not actually pay to go that far.

But that said, if during road trials we not happy with the braking balance, we will then fit ABS regardless how much modifications have to be made.

But here"s hoping we now have it where we will be happy.

Herman

Sorry that we did not have anything to post on Sunday as we normally do,

but we spent the best part of the weekend getting a massive amount of Type 3 dash's ready and wrapped.

And now they have to be shipped all over the world to round off some good looking Type 3's.

What we have however done today was to fit the drivers seat and the steering wheel for the 1st time....

This allowed me to test all the controls from a driving position.

What I did find was that the clutch pedal was very hard to push as the cable goes through 2 Bowden tubes that are in a 180 bend

There is no way I am going to retro fit a hydraulic clutch this late in the game

So we opted for the next best thing.

We decided to go for a pulley on the gearbox to half the load and half the drag movement.

So a search of the workshop produced a gate wheel with bearings fitted,

we made up a U bracket to hold it and a threaded rod to connect it to the clutch arm.

Removed the Bowden tube holding bracket off the gearbox and welded on a 8 mm tube to it for the threaded tip of the cable to mount through.

Was late by the time I got in to test the peddle, but what a joy, problem solved.

Will take a photo tomorrow.

Till then thanks for looking

Herman

As promised here are the photo's of the seat and steering wheel as well as the pulley system on the clutch.









Herman

Good thinking with the clutch pulley.
I've done this once before, also with a gate roller and found that the clutch wouldnt release enough to allow smooth gear changes. Maybe it was just my gearbox combo, but its something for you to keep in mind if these issues arise.
Because your cable is so short, you could have one made up that is totally sheethed and only comes out at the original gearbox clamp - this might help. Something like a teleflex cable

Thanks Tony,

Yes the pedal moves freely, and he changes on the blocks, not sure what he will do on the ground, will have to test it still

also thought of a new sheathed cable but that is what I have realistically with the two Bowden tubes.

The load is increasing the drag around the 180 Deg of the cable.

So the final solution would be to fit two pulleys to take the cable around the 180 Deg. without drag.

That will definitely work.

Herman