TheHaflinger.com

This discussion started in another thread, but I don't want it to hijack that thread with this....

At the moment all I have is the brake booster unit which came from Haflinger utilities version. So I have the choice still to make as to how to produce the vacuum - I suppose I need to do a bit more research into the Pros and Cons of each!

Most reliable would probably be to drill a hole in the inlet manifold - but - I presume as near the middle of the two inlet tracts, i.e. in to the carb mounting block. This could then be tapped and a suitable hollow stud screwed in to which the vacuum pipe would be fixed. Would this provide enough vacuum? I assume so as I think that is how the Haflinger Utility vehicles had it done.
Electric pump would obviously provide a more stable vacuum, I wonder what sort of amperage the pump requires. Other questions are what value does the pump need to be capable of delivering?

Still have to work out how to mount the brake booster - I need to have another closer look at the pictures in the parts book.

Any ideas, comments welcome!

John

Some ideas

http://www.amphibike.org/index.cgi?page ... owerBrakes

With a small vacuum cylinder the pump will only run when the vacuum gets low so saving a lot of power.

Looks like it would be better to fit a vacuum reservoir tank if you go the electric pump route as if the pump is small, to keep the electrical power consumption small, it takes a while to empty the brake booster reservoir again after you have applied the brakes, which means you are only likely to get or maybe two pedal pushes in any one braking procedure before you are relying on muscle power again.

I wonder what sort of vacuum you can get from a Haflinger engine? Apparently you need about 19inches of HG, which sounds like a lot, from the manifold for a brake booster to work correctly.

John

Hi John.
I have a vacuum servo running off the inlet manifold, never measured the vacuum but the servo works very well.
Cheers Nigel

Nigel,

Where did you make the connection to the inlet manifold, and how did you do it? The pipe on my servo, appears to be quite a large diameter O/D of about an inch - I/D must be at least half an inch (must admit these are guesses as I have not measured them).
Did you use rubber hose all the way to the front or metal tubing?

I really should have taken more photos of yours.

John

Hi John.
I drilled and tapped the inlet manifold along side the carb in the tubular part, I used copper pipe along the chassis tube with rubber tube on either end to link to the manifold and the servo which is mounted behind the dash, I used an after market single circuit servo and the vacuum connection is about half inch o/d.
Cheers Nigel.

Thanks Nigel,

Out of interest, what size copper pipe did you use and where are the joins to the rubber hoses? Did you make a nother hole in the footwell to get the rubber hose through or use an existing one? In which case, which one?

I am not sure I am going to be able to use the original servo I bought - it is very big and with my HID lights, space in that part of the dash is at a premium!

Need more time to study things... Trials this coming weekend.

John