Problems with the FFS Hi Spec Rear Calipers ?

[Rice crispy]

Looking at the pictures, could the arm where the cable end connects not be made a little longer which would give a bit more leverage (and more travel in the handbrake lever ? Not sure if thats ok for MOT?) Not that I know anything but its a suggestion

David

[Steve A]

Is it possible to quantify how much effort is needed to operate the caliper lever without using the cable

If you compare it with the original lever it's pretty much the same, having said that I think they work in a completly different way altogether.
Without detailed drawings of the two calipers it's difficult to guess a solution

Make sure there`s a bit of slack in the cables when the handbrake is in the off position.

Yes this is a must, I also found that adding a spring between lever and stop helped the release.
How many clicks are you getting Monty ?

I'm getting pretty chufed off with all this. Mine didn't leak but really struggled to get through the MOT handbrake test (and they were newly fitted). The tester quite rightly refused to use both hands. I've a mind to get a pair of reconditioned original rear calipers refitted now and right off the Hi Spek rears as a bad experience - no offence to Bob at all, just to Hi Spek for a shoddy product.

I can see where your coming from Alan, although I've just got through my MOT before fitting the brakes I was thinking of popping into my local station to test it on their rolling road and ask their opinions they know me and my car well and I will get
an honest opinion from them.

could the arm where the cable end connects not be made a little longer which would give a bit more leverage

Your making sense mate but I think all you'll end up with is flex in the lever or quicker wear in the mechanism which dosn't seem too robust
If mine start leaking I'll proberbly bail out myself

[bobbrown]

I'll have a look at Steve's tonight and if it needs to have a longer lever then that should be posible.
I can work out the ratio from handbrake lever to actual piston but as a rough guide the handbrake lever 3:1, caliper lever 2:1, internals 4:1
or 5kg on the lever should give about 300bar of pressure.

Bob

[Alan_C]

5kg on the lever should give about 300bar of pressure. Bob

This force should easily be enough to lock the rear wheels at any speed, but seems not to be what Steve has experienced so far. Using 2 hands to pull on the handbrake would produce far in excess of 5kg force. Please excuse me if I seem very sceptical about the improvements Hi Spec have supposedly made to the rear caliper, but past experience with this company and the frustrations they have caused us, plus not allowing Bob to test a pre-production improved caliper have left me with bitter feelings. Seems now that the handbrake piston return spring has been altered, Steve has already experienced handbrake binding and added a suplimental spring to return the handbrake caliper lever to it's rest position.

Bob - I'd welcome your investigations and further comments, and once again a harty thanks to you for working with us and Hi Spec to resolve the issues - you're a top bloke, I owe you quite a few beers next time I see you! What should have been a straight forward brake upgrade option using custom made brackets (and wonderful they are too Bob!) with off the shelf calipers appears to be turning very sour. I have doubted the suitablity of a hydraulic handbrake, not withstanding it's against construction and use regulations for a UK road car. With any luck, just a longer actuating lever on the caliper will solve the issue, but I did experience loss of handbrake action over a period of several hours, indicating internal pressure leak in the caliper. This of course could have been caused by damaged seals on the handbrake pistion due to the now known about poor design which should have now been resolved.

Cheers all!

[bobbrown]

Ok so bit the bullet and took one apart to see what changes they had made.

Alter the fluid port ………check
Alter the seals ……………check
Alter the spring position and the travel ………check

It looks on the face of it they have done all I asked, all be it they have removed the disc springs from under the piston which is a bit of disappointment as these help maintain a load on the piston but not a disaster if the seals are now good which they should be.
I can not see on the face of it why the hand brake should be weak.
Another Steve who has fitted the later calipers and put the car through an MOT had 200 on the handbrake a lower reading on the foot brake (60 to 70) but that could be attributed to new pads etc as they had not been bedded in not forgetting the proportioning valves limit the pressure to the rear.

test time tonight

Bob

[Steve A]

I can not see on the face of it why the hand brake should be weak.

I don't think it's weak, it's more a case of having the strength to apply it, I can get 3 clicks with both hands, Lesley can only get 2
If the leaking situation has been sorted (ok so far) then it's all about the handbrake and making it more user friendly.

[Avonvilla]

I'm the other Steve, i didn't really want to post as i've not had time to drive much since the new brakes are on but as Bob says i got well over 200 at the mot with only one hand to apply the handbrake, it clicks up quite easily compared to before. I haven't counted the clicks but it would be 3 or more i am guessing, i'll check and post again.

[bobbrown]

Steve, thank you for your reply, input is much appreciated good or bad with out it I have little chance of moving forward.

So what is your excuse for not driving the Elan it can not be the weather as it has been good for a while now.

Bob

[Avonvilla]

Work, a girlfriend with a horse and a mother who thinks i have nothing better to do than her diy

[bobbrown]

they do not seem valid excuses

[Avonvilla]

they do not seem valid excuses

There the best i can do

[Monty]

Yes this is a must, I also found that adding a spring between lever and stop helped the release.
How many clicks are you getting Monty ?

I`m still on the Hi-spec Version 1, when 1st fitted could only get 1 maybe 2 clicks and now get 4/5 clicks (using 2 hands which doesn`t bother me one bit). Done a couple of trackdays on these and a few thousand miles i`ve not lost any fluid yet, (but i`ve not checked for leaks)


If the MOT guy won`t use to hands ( ) then i would use a different MOT place as he`s just being a Tw*t

[bobbrown]

Looked at SteveA's car last night and it looks good, although the lever takes a bit of effort to get to 3 clicks it is not unreasonable.
I think part of the problem of the effort required is down to the position of the lever as it is not in the best of places on the tunnel.
I looked at the Astra I have and the handbrake lever is on the floor and much easier to operate than the one in the Elan even on standard rear calipers as the Astra is more of a straight pull up. That said I did try the handbrake leaning in to the car and the amount of force to get to 3 clicks was not that great, it was not like I had to play at Geoff Capes to get the three clicks and rear brakes seemed well applied.
If Avonvilla can get 200 on an MOT just after swapping the calipers over then that indicates a good hand brake.

I would always recommend that any car is left in gear as an added precaution and it is something I always do.

Now all I have to do is get Hi Spec to produce them, now there's a challenge!

Bob

[Alan_C]

If 200 kgf (Bob, I presume the figure was in kgf?) can be acheived on the handbrake then I'd say the handbrake is working perfectly, and the cables/adjuster needs to be carefully set up so that with a good single hand tug the lever will just clear the next click. Just so there are some comparison figures, my original rear design calipers failed the MOT with handbrake figures of 80 and 78 kgf. The footbrake figures were 42 and 118, but this imbalance is due to failed rear presure limiting valves which have now been replaced. The imbalance wasn't enough to fail the car, but the handbrake force was as it equated to an efficiency of 14%, 16% is required to pass.

[Avonvilla]

It was just over 200 whatever the mot station reading equipment measures in. My original hi specs had a very poor handbrake reading. Same mot station.

[Alan_C]

Now all I have to do is get Hi Spec to produce them, now there's a challenge!Bob

So all seems good with the re-design, many thanks to those that have fitted and supplied some test results, and to Bob once again for putting in more time on this. We just need to get Hi Spec to make the rest, then I can get some fitted and take my car off the axle stands it's been up on for the last few months. If and when I get some fitted I'll ask the MOT station to run a brake test for me and I'll publish the findings.

Cheers all!

[saska]

Bob's point about the position of the handbrake is well made. Thinks that's why the S2 has a longer handbrake handle than the SE.
If I remember correctly from East Kirkby SteveA has an SE and I'm pretty sure Avonvilla has an S2 which could account for the slight difference in effort.

If with the Mk2 Hispec I can get 3 clicks on the handbrake and the buggers don't leak, I'll be a happy bunny.
Don't want to go back to OEMs due to the frt/rear imbalance with 294mm fronts.
Thanks to all for your efforts -- particularly BobB.

[Avonvilla]

Yes mine is an S2.

[bobbrown]

There was a modification to the lever but not sure how relevant this is

lever.jpg

[bobbrown]

As far as the others that are still waiting on the replacements, Hi Spec have said they will start getting them done over the next couple of weeks, so allow three to four.
Some I know are more urgent than others (cars off the road) and I have asked that they do the urgent ones first.
This shows those I know are urgent in red and the ones I have or have sent out are in yellow.

list.jpg

If you feel you need them asap and you are not one of the people in red let me know but they are making a larger batch (hopefully all) so they sould all startto appear on the scene

Bob