Hydraulic hand brake

PostPost by: sk178ta » Tue May 29, 2007 10:34 pm

Rob thingy with a pistachio Sprint has mounted a handbrake lever between the seat and the centre tunnel. He was telling me that he`d left his original cable handbrake in place and mounted the lever operating a small master cylinder which tee`d into the brake line to the rear brakes. What a great idea, I thought, but, on reflection, wouldn`t that make for a spongey (or worse!) pedal to the normal brakes? Or am I missing something?
Jim
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PostPost by: Elanman99 » Tue May 29, 2007 10:42 pm

[quote="sk178ta"]Rob thingy with a pistachio Sprint has mounted a handbrake lever between the seat and the centre tunnel. He was telling me that he`d left his original cable handbrake in place and mounted the lever operating a small master cylinder which tee`d into the brake line to the rear brakes. What a great idea, I thought, but, on reflection, wouldn`t that make for a spongey (or worse!) pedal to the normal brakes? Or am I missing something?
Jim[/quote]

Jim

I couldn't comment on the sponge brake bit but I do wonder how Rob managed to find rom for a lever of any sort between the seat and the tunnel!

What is his reasoning behind having two master cylinders on the same hydraulic line, snds like a recipe for even more trouble than the original cabel handbrake.

Ian
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PostPost by: tower of strength » Tue May 29, 2007 11:07 pm

This was a common mod for the rally escorts with rear discs, a friend had a similar set up on his MK1 Capri Cologne replica, to appease the MOT tester we had to run a cable that linked the lever to both rear calipers so it would go tight as the hand brake was operated!!This car had monster stoppers and no spongey pedal issues.

I seem to remember that it had a shut off valve (similar to a drag racers line lock) to prevent the handbrake pushing fluid back into the brake master. Memory is a tad fuzzy these days though!!


for a simple parking brake mod that would hold the car on the steepest of steep hills I'd go for a line lock valve in the rear brake line. Simply press brake pedal hard and operate the valve, this would maintain the rear brake pressure untill released.
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PostPost by: 1964 S1 » Wed May 30, 2007 1:01 am

Today is not April 1st.
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PostPost by: tower of strength » Wed May 30, 2007 1:04 am

1964 S1 wrote:Today is not April 1st.


felt like it was, yesterday!!
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PostPost by: sk178ta » Wed May 30, 2007 8:28 am

April 1st ? No I don`t get it. Rob`s lever was nicely made out of a flat stainless plate about 5mm thick which squeezed in between the seat and tunnel. Once clear it was fitted with a small but nice tubular handle. The mechanism itsel has room under the seat.
He fitted it for 2 reasons, 1: it worked without constant adjustment, and 2: his wife, like me and mine, can`t comfortably reach the handbrake wearing seatbelts.
Jim
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PostPost by: steveww » Wed May 30, 2007 9:29 am

I can't reach the regular hand brake when the harness is done up. I just use heel 'n' toe for hill starts. Not sure my wife could manage that though :shock:
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PostPost by: SADLOTUS » Wed May 30, 2007 9:53 am

I've often thought of trying to design a small rear motorcyle caliper gripping a small disc on the diff/prop join, activated by a line lock or small hydraulic handbrake of some sort. I think rodders and custom cars sometimes use a similar design.
Never got round to it, always managed to get the H/brake to work well enough for the MOT, and heel and toe at all other times!
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PostPost by: john.p.clegg » Thu May 31, 2007 6:31 am

Just a quickie,going to work,does the handbrake have to work on the rear wheels only or can one lock-up all four wheels (I have a cunning plan)....


John :wink:
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PostPost by: john.p.clegg » Thu May 31, 2007 6:37 am

P.S.
it's not 6:31 but 7:31 I hope....


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PostPost by: sk178ta » Thu May 31, 2007 7:54 am

John, ideally just the rear wheels, handy round the cones on driving tests, but`s what`s your cunning plan?
Jim
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PostPost by: alaric » Thu May 31, 2007 8:56 am

Hi.

If you locked the prop before the diff, then unless you had a limited slip diff, wouldn't the car roll forward if one wheel was on slippery ground? You've effectively reduced the handbrake effectiveness to that of the least gripping rear tyre. I guess it would most likely stop again, but only once that tyre was gripping again i.e. once it's going, it could keep going. If I've misunderstood that earlier post then 'oops'.

Another thought re the hydraulic handbrake solution. If your discs are hot when you park, when they cool down they contract - not a lot, but maybe enough to let go. Is a hydraulic solution as good as a cabled solution at absorbing changes like that? I don't know, just a thought. A freind of mine recently watched his +2 roll down the hill into a lampost 'cause the standard handbrake let go - we still don't know why it happened. There was no apparent fault with the handbrake.

Sean.
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PostPost by: Elanman99 » Thu May 31, 2007 11:54 am

This is getting silly!

Apart from the fact that there is nothing wrong with the standard handbrake (well just one, the lever position) I understand that it is a legal requirement to have an totally independant handbrake.

On modern cars the only shared part of the handbrake might be the pads but the rest is mechanical whether it is electrically or directly operated.

Hydraulic 'Line Locks' do have legitimate usage and probably have enabled some cars to pass the MOT but I would not want to rely on it especially on a car without a split system.

On the 2 seater Elans not only is it difficult to reach the handbrake lever but the inertia of the drivers body acts in the wrong direction reducing the force just when it might be needed most.

Going back to the original post, maybe the best option is to use a thin mechanical lever between the seat and the tunnel to operate the existing mechanism

Ian
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PostPost by: GrUmPyBoDgEr » Thu May 31, 2007 1:23 pm

I once had a very nicely modified 1959 Elite. The PO had "modified" the handbrake.
The lever was an Elan umbrella type under the dash. The cable from it went through the bulkhead & then back through it to connect to the footbrake lever via a clevis pin.
A cunning plan 8)
The original handbrake pads etc were left in place but not connected, so no emercency brakes if the hydraulic system let go anytime. :oops:

The MOT testing station were always very impressed with the handbrake efficiency though. :lol: :lol:

To save putting loads on the hydraulics for long periods I used to park the car in gear only & pointing the front wheels inwards on hills

Cheers
John
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Editor: On Sunday morning, February 8th 2015, Derek "John" Pelly AKA GrumpyBodger passed away genuinely peacefully at Weston Hospicecare, Weston Super Mare. He will be missed.
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PostPost by: john.p.clegg » Thu May 31, 2007 3:53 pm

Jim
The cunning plan is to route the handbrake cable to a hydraulic tap in line (spring loaded) so a press of the footbrake,a pull of the handbrake and all four wheels locked....release the handbrake and away you go....simple isn't it......or is it?

John :wink:
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