Handbrake not strong enough! Any tips?

[Heuer]

This shows it:

[kingzetts]

Yep, that's the one!

[Heuer]

Interesting both the block and arm are missing from the SC Parts drawing. The above drawing is from the Jaguar Parts catalogue which makes you wonder if the repro parts are wrong! The SNG one seems to be all there however:

[PeterCrespin]

An important aspect of facilitating the 'pinch' action/re-action of the inner and outer hndbrake cable is its mounting. The outer must be free to move relative to the body, cage and compensator pivot. In other words neither stretched nor clipped/tie-wrapped to anything. If the outer cable cannot clamp the compensator arm and move with it in opposition to the tightening inner cable, it is like trying to cut with scissors or tin snips with one handle resting on the bench and pressing down on the other. There are other aspects to keep an eye on and the compensators with the adjustable tie link maake lining everything up correctly much easier. It's a perfectly good handbrake if set up right, it's just not very tolerant of being thrown together carelessly and it does suffer if not tregularly lubed

Pete

[44DHR]

I have just sent a PM to Andrew to call me as also being on the Isle of Wight I can certainly help him. This has to one of the most common Jaguar IRS MOT issues and always rears it head giving concern on basically a fundamentally poor design of mechanism. John's, (kingzetts) description of how the mechanism works is spot on. One modification is to extend the throw on the handbrake lever by extending it, but the most common fix is to tie down the mechanism using two jubilee clips, one round the threaded cable adjuster and the the other around the rear anti-roll bar using siezing wire to pre tension the handbrake mechanism. This effectively restricts movement of the nearside lever, but fully engages the offside. Worst case if too much tension is applied, the offside lever is fully engaged which will only lock that side. I am aware of MOT stations passing a car with this modification as although the two rear wheels are not equally locked, the overall holding pressure is sufficient to hold the car. I am not recommending this "modification", just stating how it is overcome and viewed by some sympathetic testers on what is basically a component, I personally hardly ever use. The use of handbraked discs and the effects of them loosening off as very hot discs cool is well known. After a track day, I do not apply the handbrake - just engage the gearbox on level ground.

regards,

Dave

[skiday]

All the posts have been very welcome - thank you. I am pleased to say that Alec at St Helens Garage got the car through it's MoT at last. He chamfered the pads (which I might add, should really come ready chamfered given the known design of the mechanism and it's failings!) and did the modification, but whether it was exactly as described here I can't be sure. Anyway - it's done now. Irony is ? I almost never use the hand brake! I'm sure this problem will crop up again so this thread will be useful to many others in the future I'm sure.

Cheers

Andrew

[christopher storey]

AAARGH !! Andrew, I hate to tell you this but the pads should not have been chamfered. That is how they turn out when they are worn to the extent that you start to have troubles of the very type you have suffered. Too late now, and at least you are through the MOT

[Dave K]

Chris C just informed me that he did the mod I explained and his handbrake is now fully tight on both sides in 4 clicks and it will stay that way forvever, no more adjusting, job done. It really is simplest, cheapest and effective mods you can carry out on an E-Type.

Dave

[ChrisC]

I concur. It was an easy mod to do and its pretty easy to take off the handbrake mechanism to achieve it. My thanks go out to Dave for his help on the how-to... Cant think why Jaguar didn't do this originally...

[Dave K]

Chris, they did later on the XJ6.

Dave

[Bob Falfa]

This has to one of the most common Jaguar IRS MOT issues and always rears it head giving concern on basically a fundamentally poor design of mechanism. John's, (kingzetts) description of how the mechanism works is spot on.

One modification is to extend the throw on the handbrake lever by extending it, but the most common fix is to tie down the mechanism using two jubilee clips, one round the threaded cable adjuster and the the other around the rear anti-roll bar using siezing wire to pre tension the handbrake mechanism. This effectively restricts movement of the nearside lever, but fully engages the offside. Worst case if too much tension is applied, the offside lever is fully engaged which will only lock that side.

Dave

Interested in your idea of using jubilee clips to sort handbrake issues##I understand that you would place one over the cable on the off side but unsure where the other clip should go - when it says the cable adjuster can you clarify please? Many thanks.

[44DHR]

Bob,

The method involving Jubilee clips is a bodge and I have since been educated by Dave K in the correct and reliable way to resolve the handbrake adjustment once and for all. I sent a PM to Dave as requested by him, (see his post dated May 18th 2012 on page 1 of this post) and he kindly sent me photos of what to do. As Dave pointed out this is how Jaguar themselves resolved the problem on the XJ6. I did this engineered solution to the issue and my handbrake is now fully functional and will remain that way. The Jubilee bodge basically puts one clip around the threaded part of the cable adjuster, (the part with the adjusting hex head), before it enters the swivelling block and is used to pass through several loops of siezing wire through to another Juliblee clip mounted around the anti-roll bar. By tightening the siezing wire between the two clips and then tighening the clips down themselves, all this does is pre-tension the adjustment assembly by pulling it forward towards the anti-roll bar. It is a bodge as it only makes one caliper firmly grip the disc, (the offside IIRC) and some MOT stations used to allow this through as the PowerLok allowed the whole axle to be held.

Dave's solution really works and as he did me the favour and has asked for this modification not to be put on any website, I respect that and won't repeat what needs to be done - but it is real easy modification to do once the compensator assembly is unbolted from the axle cage. It does also require the use of the aforementioned XJ6 return springs available easily from the "usuals" and making up some form of spring mounting where they are required to mount onto the cage. Hopefully, Dave would advise others if they PM him.

regards,

Dave

[Heuer]

SNGB are now selling this upgrade part for ?100:

[kingzetts]

I was involved in the development of that SNGB part and have a prototype version on my car. The standard setup contains a scissor linkage which converts each mm of travel in the end of the handbrake lever into 0.5mm movement at the end of each handbrake caliper operating lever. With the standard linkage in good condition, properly adjusted, and with the handbrake self-adjusting mechanisms in good order and unworn, there is just enough travel available in the scissor linkage to apply the handbrake firmly when the pads are worn just to the brink of the point where the self-adjuster moves them in another click, or to get the adjuster to click over another notch when that point is reached. If the self-adjusters are worn, you need more travel before they will work. The standard setup runs out of travel either when the scissor linkage binds on itself or when the clevis on the end of the inner cable binds on the cable outer sheath (both happen at about the same time). In my case the standard setup simply would not get the adjusters to give me the correct clearances, did not give enough overall travel to compensate for this, and the handbrake would not pass the MOT. Having fitted this item the handbrake then passed the MOT with no further work.

The key point about the SNGB part is that by using twin cables instead of a scissor link, you get twice as much linear movement at the end of each handbrake caliper lever for a given movement of the end of the handbrake lever. This avoids any risk of the either running out of cable travel or of the linkage binding before the handbrake is fully applied. This has the side effect of reducing the lever travel required to apply the handbrake, and also I think of increasing the force required to achieve a given clamping force onto the discs. The benefit for me of this design is that it can accept much more free movement in the handbrake caliper mechanisms which, since my adjusters were worn and would not allow the pads to sit as close to the disc as ideal, allowed me to avoid removing the IRS to fit new adjuster mechanisms.

If you have the standard linkage in good condition and well adjusted, you do not need this alternative design. The mod Dave Kerr champions does work well by ensuring you get the most out of the linkage travel available in the standard link, but it does not give any more ultimate cable pull than the standard design. If your linkage is working well, fine. Or, try Dave's mod and if it works, fine. For me, I'd suggest buying this alternative rather than a replacement standard linkage (should you need a new linkage for any reason) -it's cheaper, for a start - unless you're sold on originality, and give it consideration if you want a bolt-on option which will make it much less critical that your handbrake is perfectly adjusted.

[Dave K]

The good thing about the SNGB set up is no cutting of the original handbrake linkage set up and for most people that makes it a winner.

Dave

[Dave K]

I was watching Wheeler dealers last night, the one where they did the S3 V12.
When Ed drops the IRS if you look very carefully the car has the mod I passed on done the handbrake mechanism.
You have have to look very carefully it's only shown for a split second.

Dave

[tinworm]

Well I do wonder why so many people have handbrake problems - My 3.8 (with girling calipers ) has just passed the mot with the handbrake showing 23% on the testers meter. I wonder if this is a normal reading or some sort of E- type record. I have set out my argument in earlier posts which you can read - above.
Reading from the 'Motor' magazine road test report from October 1964 they say " The handbrake working on the rear discs is quite powerful and will hold on a 1-in-3 hill "
So how did we get to the stage of E- type handbrakes do not work at all and have to be modified ? - eh?
Cue disgruntled Experts responses below.

best regards Barrie

[Dave K]

All I can say is why did Jaguar modify the design in later years if it was good enough already?

Dave