DIY Hydraulic Handbrake

[darkstar]

Im interested in doing my own Hydraulic handbrake setup. I have access to some clutch master cylinders and an engineering workshop, so tooling is not a problem :)

I have seen some setups and im wondering how they work if you dont use a master cylinder.

ie:
http://www.rallysystems.com/images/handbrake.jpg

http://www.prepfab.co.uk/Parts/images/handhori_jpg.jpg

http://www.gorallying.com.au/thecar/build16.jpg

The last picture looks rather interesting.

It appears to have a brake bias adjuster near the gear boot inline with one of the brake lines that goes to the master cylinder.


Is the hydraulic circut like this for the most typical hydro handbrake?
(Normal Brake Master Cylinder) -> (Handbrake Master Cylinder) -> (Pressure from handbrake leaver) -> (rear brakes).

Essentially what im trying to ask is that you can put the hydraulic handbrake Master Cylidner in line with the rear brake lines and it wont effect normal braking and biasing towards the rear, as when the handbrake isnt activated the fluid just pumps through normally.

I was thinking that the fluid will chose the least path of resistance and possibly go back into the master cylinder using this setup when you activate the handbrake instead of going into the rear calipers.

Ive done a search on the forums and i came up nothing :)

If you could contribute some examples or own work that would be great.

Cheers

[fro]

It doesn't show up in the search, 'cause it appears to still be broken, but check out this thread http://pforums.company-hosting.com/forums/showthread.php?t=67177958, and maybe snd demuire a PM about his solution in the end...

[darkstar]

Can anyone shed some light on how the hydraulic circuit works please?

[dattoman1000]

Fluid in fluid out......simple
They have to use master cylinders......I don't understand the orignial inferrence that they don't.
The cylinders are a centre valve style internally so when in the relaxed position fluid travels thru them normally.....once the lever is actualted the centre valve seats on the bottom on the cylinder bore and shuts off the flow in and actuated the flow out.

(Normal Brake Master Cylinder) -> (Handbrake Master Cylinder) -> (Pressure from handbrake leaver) -> (rear brakes).
Spot on McDuff

[NISMOgemini]

wouldnt it be easyer to pay 300 odd bucks then dick about trying to make one??? (speaking from a lazy persons point of veiw here) :D

[demuire]

You also have to make sure you get the master cylinder size right, and that you get the pivot and axis points on your handbrake handle right, or it won't work all that well.

This is my setup:

http://images8.fotki.com/v107/photos/1/12090/1208626/PICT0662-vi.jpg

[fro]

Nice work. That's turned out very neat.

What's the central "box section" made out of? I've got one in my rally car that the previous owner must have made, and it flexes a fair bit.

I'm looking at making a new one of my own design, and want to avoid these flex issues.

And yes, it will be a vertical detachable handle, push-activated, horizontal-master-cylinder jobbie, if I can figure out how to do it!

[demuire]

Umm... It appears to be RHS, about 3mm walls? I didn't make it, I bought it. I figured it would be worth the not having to stuff around trying to get everything right, especially because my welding and fabricating skills are really rather average.

Here are more photos:

http://images7.fotki.com/v106/photos/1/12090/1208626/PICT0663-vi.jpg

http://images8.fotki.com/v107/photos/1/12090/1208626/PICT0664-vi.jpg

http://images8.fotki.com/v108/photos/1/12090/1208626/PICT0646-vi.jpg

http://images8.fotki.com/v107/photos/1/12090/1208626/PICT0647-vi.jpg

[fro]

Bought it from?

I know that a mob called Seemore Motorsports do handbrake gear that looks pretty tidy (like this one (http://www.seemore.com.au/product.php?id=4681)).

Hmm, it'll be a whil before I replace mine, anyway...

[demuire]

I got mine from KCF Rallysport in Brisbane, but yes, Seemore also make a rather nice one.

[rowdytoot]

that seemore motorsport pro one will rip into your left leg something fiece though mounted where it is..... though I do like the vertical lever concept I just think it needs to be mounted somewhere else.


your's looks the goods fook... :)

Rowds

[thehelix112]

Fluid in fluid out......simple
They have to use master cylinders......I don't understand the orignial inferrence that they don't.
The cylinders are a centre valve style internally so when in the relaxed position fluid travels thru them normally.....once the lever is actualted the centre valve seats on the bottom on the cylinder bore and shuts off the flow in and actuated the flow out.

(Normal Brake Master Cylinder) -> (Handbrake Master Cylinder) -> (Pressure from handbrake leaver) -> (rear brakes).
Spot on McDuff


Thanks for that! Makes sense. :)

[demuire]

Ta :) Now if only I knew how to drive :P