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MG MGB Technical - Handbrake Cable Adjustment
I have a '68 mgb roadster and a '71 MGBGT and both of them suffer from stretched (read "well used") handbrake cables. Both seem to be at the end of their adjustment. (The spring is squashed to the max.) Can someone advise if there's a way to continue to adjust the cables without having to replace them? Maybe there's a neat device for taking up slack in the cable etc? Help. |
R P Shoebridge |
Ray I purchased a new handbrake cable which was too long. This is a common fault with new cables. I drill a new mounting hole in the transmission tunnel for the front end of the cable. It was about one inch further to the rear but the distance can be whatever suits your cable. Very neat and very simple. Peter |
Peter Scott |
I too had a problem with a new cable being too long. I ordered one of each of the cables from Moss. Niehter would fit. (both were too long). I went to a local cable manufacturer and they cut the end off of the main cable (end that goes to the wheel) and installed a new cable stop at the correct distance. Then they installed the stop using a 10 ton press just for the purpose. It cost $10 but when I installed it , it fit like a dream only 4 clicks to full brake pressure. |
Cris DeYoung |
You may consider adjusting the rear brakes. They may be out of adjustment. rn |
RN Lipow |
There is a device sold that you can clamp on the cable that will take up the slack. I just picked one up recently at PepBoys. All the guys behind the counter said "we don't sell anything like that" but I remember them for the old days. They carry a line called 'HELP' that contains things like generic window crank handles and stuff like that. It's got a little hook that draws the cable in as you tighten the nut causing the cable to become shorter. Now my handbrake actually does something. |
Dana Wilson |
Dana I too have that problem with my 79 MGB... I'm going to make a stop at the PEPBoys to check out the section and see if I can find the part your talking about. Thanks Don |
Donald Wheeler |
I had one of those PEP Boy type adjusters on the calbe that was on my MG when I bought it. It did the job fine although it looks clunky. Finally the cable snapped and I replaced it with a new Moss unit. It fit perfectly on my 1965. Be sure to have the rear brakes properly adjusted. Otherwise the hand brake tends to bottom out agains the slot in the backing plate. |
Robert McCoy |
put a small distance "tube" prior to the main adjst' nut (and a lock nut after it so it doesn't unwind). For your "distance tube" you might consider a few nylox nuts as the nylon head part of the nut is about the same shape as the adjuster nut and should centre the cable. |
Peter |
Was just in the workshop fiddling around. Came across a few springs, used inside the windshield wiper arms. It looks like it might serve well as a spacer between the cable sheath and the tunnel cable fixture. Just have to wait until wind-chill factor is not an issue. Any thoughts? |
glg |
I fabricated a clamp that holds the nipple on the short inner about an inch away from the trunion on the lever on the diff casing. |
Paul Hunt |
This is one Moss and others should do something about--a simple matter of the Moss buyer telling the part manufacturer what the correct spec is. Cost neither company a penney more. There are two different sizes, one for disk wheels, one for wires and as cris says above, neither are short enough. This is a safety issue. An important feature on our cars is generally inop due to incorect purchasing specs and I think our suppliers should take note. Paul |
Paul Hanley |
There is a good side to all of this "lengthy" discussion. I converted my GT to disk wheels from Wire so I could install modern alloy wheels. The old cable for the wire wheels - stretched as it is -- just fit the wider rear axle assembly very nicely. Barry |
Barry Parkinson |
Barry. I am glad that you touched on this point. It is central to the matter at hand. The way the handbrake works is that the handle (a lever) is applied to stretch the cable. As it is applied, it does two things. First, the initial movement causes the rear brake shoes to move outwards and make contact with the rear wheels. This is not sufficient to either hold the car in place or apply any great braking force unless the handbrake is held in position. The second thing that happens is that the handbrake cable is put under tension. When the handbrake lever is left in an upwards position, the tension of the cable is applied to the brake shoes to hold the shoes firmly against the brake drums and provide resistance to movement. Cables which have stretched beyond their normal limits have significantly less clamping power available and will not work as effectively as a newer cable which still retains the ability to provide tension to the system. Thus, the use of an older, stretched out cable results in a lowering of the effective ability of the emergency/parking brake system. Les |
Les Bengtson |
Les The spring tension of a stretched cable is what keeps the shoes tight to the drum. A cable that has stretched perhaps 4% of it's length over 35 plus years would have very little loss of ultimate strength. In fact it would seem to me that the cable would be work hardened and be less likely to stretch and lose tension after the lever is set, than a new cable. One more click on the hand brake lever would do it in any case. I have no complaints about the way me e brake works even if it is stretched. Part of the "lengthening" I am sure is not of the cable, but slop developed over the years in the connections at the brake lever, the pins in the Y connection and at the backing plates. Once the wires get too hard they break. That fracturing would seem to me to be the motivation to go with a new too long cable. Barry |
Barry Parkinson |
Barry. Someone such as yourself, who is an experienced owner, can make some interpretations as to what the condition of such parts are. Some of the newer owners cannot. A "work hardened" cable would be one that has lost its ability to stretch and place the proper tension on the system. Similar to worn distributor springs that allow the mechanical advance to come on too soon. This is a rather subtle thing. The "old heads" can feel when the cable is no longer placing tension on the rear shoes when the hand brake is applied. Some of the newer members, not having many years of experience, will not notice this. Hence, your post was a good foil to mention such things. Les |
Les Bengtson |
What Paul Hanley says may be true of some suppliers of non-OE kit, and is very common across the whole range of parts as we know. But I have fitted OE handbrake cables of both types and had no problems. The 'shortener' I fitted was to a disk wheel cable that had been on my roadster for very many years (long before my ownership) before being replaced when wire wheels were fitted, then went onto the V8 when its cable frayed. It was only because I like mine to be on at 4 clicks instead of 6 that I fitted the shortner to the V8 when I had used all the adjustment up. Having the two to compare there is as much 'spring' in the quite old V8 cable as in the much newer roadster cable, and I do agree that it is only the spring in the cable that applies the force to the drums. A truly solid linkage would only apply any pressure if you could just force the lever past a 'click'. Between thew quite widley spaced clicks there would be little if any braking force. One area of significant wear in the linkages I have noticed over 30 years of BL handbrakes is in the levers inside the drum. Not only can the pivot wear (and sieze at the same time if not 'washed' with penetrating fluid and regreased reguarly) but so do the notches where the shoes ride. These can increase in depth meaning that the end of the lever has to be pulled further and further away from the backplate before the shoes reach the drums (which incidentally also wear and have the same effect). The lever (to which the end of the cable connects) will apply greatest force if it is parallel to the backplate when pulled on. As more and more wear occurs this gets pulled further and further away from the backplate and reduces in effectiveness. As well as new drums my levers 'notches' and been welded and filed to bring the angle of the lever outside the drum back to parallel with the backplate when applied. |
Paul Hunt |
Back to the original question: Can someone describe or attach a jpg photo of the handbrake cable "shortening" device? ray@seatours.co.nz I may be able to construct one from a few pieces of #8 wire. (That's how we do things here in New Zealand. In fact, did you know that our last yachting entry that lost us the Americas Cup had the rigging held together by #8 wire? It was our secret weapon. I think the Aussies are going to pinch the idea for their next attempt to "lift" the cup!) |
R P Shoebridge |
Try http://www.mgb-stuff.org.uk/wn_brakesframe.htm and click on 'Handbrake', then on the thumbnail near the bottom of that section. An alternative would be anything turning the long inner through an 'S'-bend, preferably mounted near the hub to stop it flapping up and down under its own weight. |
Paul Hunt |
This thread was discussed between 24/01/2004 and 07/02/2004
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