hand brake/e-brake/parking brake adjustment question

[penciltester]

So both cables are attached. Passenger side locks up like a champ. Drivers side not so much...or at all. We followed the instructions for adjusting the brake. Remove pin, turn screw. The thing does not adjust. We turn the screw and hear a clicking noise but it doesn't make anything tighter.

Anyone else have this happen?

Thanks

[jwrayth]

http://www.jaguarclassicparts.com/illustrations/images/mj3108.jpg

As you adjust the screw you should physically see the caliper halves moving closer together. If that's not the case, then I'd imagine part 5 in the above diagram is spinning freely as you turn the screw, and as such is not pulling the two calipers together. It may be worth taking it off and cleaning up the insides, I know it was with my car over winter as the mechanism was not fitted correctly internally on one side, and just needing cleaned and re-greased on the other;

http://i.imgur.com/zHwO0bb.jpg
http://i.imgur.com/hdZDXYr.jpg

[David T]

Those are self-adjusters and are useless. They don't work. You may have to keep part #5 from spinning as you try to tighten that big screw. don't forget to replace the cotter pin. Try to adjust so both brakes tighten evenly. No matter how well you get the E brakes to work they won't stop the car very well but they are useful on the 5-speeds to keep it from rolling when parked.

[jwrayth]

Whilst I agree that the self-adjusting mechanism isn't really any good, I'd disagree that the E-Brake doesn't work well. If yours isn't working well then it needs adjusting/investigating. 3 Clicks and mine holds like a champion :)

[David T]

Whilst I agree that the self-adjusting mechanism isn't really any good, I'd disagree that the E-Brake doesn't work well. If yours isn't working well then it needs adjusting/investigating. 3 Clicks and mine holds like a champion :)

I didn't say it wouldn't hold, just try stopping the car from, say, 30 MPH and see how long it takes.

[jwrayth]

Being that it's primary purpose is as a parking/hand brake and works great for that when calibrated correctly, I don't see the problem. The circumstances you describe only really factors in under an emergency situation where the main brakes have failed or are failing, and in that case I'd be glad to have any braking rather than none.

[David T]

Being that it's primary purpose is as a parking/hand brake and works great for that when calibrated correctly, I don't see the problem. The circumstances you describe only really factors in under an emergency situation where the main brakes have failed or are failing, and in that case I'd be glad to have any braking rather than none.

Well, it IS called the Emergency brake aka parking brake. And if the service brakes don't work that is all you got unless you want to stop the car by running into something!

[jwrayth]

Well, it IS called the Emergency brake aka parking brake.

Being a stickler for detail, the workshop manual and owners manual both refer to it as a parking brake. I think it's disingenuous to claim it's not fit for purpose by complaining it's not very good at a secondary job it's not designed for.

Why am I being so pedantic about it? Because I think perpetuating that the hand-brake is "not very good" leads people into accepting whatever state their system is in rather than taking the time to correctly adjust it and make their car more reliable and safer.

[David T]

Being a stickler for detail, the workshop manual and owners manual both refer to it as a parking brake. I think it's disingenuous to claim it's not fit for purpose by complaining it's not very good at a secondary job it's not designed for.

Why am I being so pedantic about it? Because I think perpetuating that the hand-brake is "not very good" leads people into accepting whatever state their system is in rather than taking the time to correctly adjust it and make their car more reliable and safer.

While it may not be called the Emergency brake in the manuals, in the USA it is considered to be an emergency brake and you WILL grab it and pull it for all you are worth if the service brakes don't stop the car! I say it isn't great because it isn't! No amount of adjustment or fiddling is going to make it any better than what it is. And you will never get the automatic adjuster to work either. Since it is also on the automatics and they don't require a parking brake, why is it there? Could it be because it is required to have a mechanical brake in case the hydraulic service brakes fail? In fact on EVERY car made with hydraulic brakes there is (and it is required) a mechanical braking system meant to be used in the event the main system fails. Even if the car has an automatic transmission. And if that doesn't work I would not rule out trying reverse!!!!!!!!!!!! I agree everyone should test their parking brake and if it doesn't hold it MUST be made to work and work as well as you can make it. One day your life (or someone else's) may depend on it. BTW the owner's manual also calls it the handbrake besides also calling it the parking brake.

[jwrayth]

I've already agreed that in an emergency situation where the hydraulic brakes fail it's better to have something than nothing. That still doesn't make it the primary purpose of the parking brake though. The fact it is separate from the hydraulic braking system is indeed so it can act as a back-up under emergency situation is common sense design to allow it to function as a back-up system if the main brakes fail.

You're not pointing out anything new or relevant to your original claim that it doesn't work very well. It works well for what it was intended to do, and in an emergency it's only going to work as well as you have calibrated it for it's primary purpose. Telling folks "No matter how well you get the E brakes to work they won't stop the car very well" is neither informative or useful.

[Dangermouse]

About a year ago, a guy in the UK called Darren C really researched this issue and found that the key problem in the effectiveness of this brake is that <20% of the pad surface comes in contact with the rotor when it is applied due to the pads being square cut (from the supplier) rather than taper cut.

http://i265.photobucket.com/albums/ii221/DarrenLCollins/DeloreanHandbrake005_zpsebb6d55f.jpg

http://i265.photobucket.com/albums/ii221/DarrenLCollins/DeloreanHandbrakeangle_zpsae1c3fcb.jpg

Its a compelling read

http://www.deloreaneurotec.uk/viewtopic.php?f=21&t=4125&hilit=brake

[PJ Grady Inc.]

While it may not be called the Emergency brake in the manuals, in the USA it is considered to be an emergency brake and you WILL grab it and pull it for all you are worth if the service brakes don't stop the car! I say it isn't great because it isn't! No amount of adjustment or fiddling is going to make it any better than what it is. And you will never get the automatic adjuster to work either. Since it is also on the automatics and they don't require a parking brake, why is it there? Could it be because it is required to have a mechanical brake in case the hydraulic service brakes fail? In fact on EVERY car made with hydraulic brakes there is (and it is required) a mechanical braking system meant to be used in the event the main system fails. Even if the car has an automatic transmission. And if that doesn't work I would not rule out trying reverse!!!!!!!!!!!! I agree everyone should test their parking brake and if it doesn't hold it MUST be made to work and work as well as you can make it. One day your life (or someone else's) may depend on it. BTW the owner's manual also calls it the handbrake besides also calling it the parking brake.

You are correct that the parking brake fitted to our cars is not a good emergency brake. In fact facing an emergency situation the NOS pads are likely to shear off their backing plates completely! I see many cars come into the shop with one or more pads missing. When that happens they are useless. It also requires meticulous attention to the cable and pad adjustments to work effectively.

What you have to remember David is that this is a design that debuted on the legendary Jaguar XKE and is now over half a century old. At the time it was state of the art as virtually every other car on the road was stopping with heavy, now almost obsolete, drum brakes. So give it a break!

At least the later Girling replacement pads use tabs besides adhesive to better lock the pads in place in an emergency situation. Fitted with later pads, properly adjusted and carefully broken in, I'd venture to guess that it would probably stop almost as well in an emergency situation as some current parking/emergency brakes. Keeping them in proper adjustment is the real rub (puns intended).
Rob