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Andrew Fock
Australia
370 Posts |
 Posted - 23/05/2017 : 11:33:49
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My N type is about to get a rebirthing so I am looking at improving the braking. While initial light pedal pressure produces what seems like quite good retardation, if more urgent braking is required with high pressures, there is always a feeling that the cables are stretching and the increase in braking is not commensurate with the force.
However, when I built up my P type with different drums, the same level of application locks up the wheels and the pedal remains solid in feel.... so I assume that the problem is actually the original drums flexing.
While I could use similar drums to the ones on the P type, I'm keen to keep the original appearance on the N.
Does anyone make drums that look like the original ones but are less prone to flexing?
If not is there interest in getting some sets made?
We have a supplier locally who could potentially do this but it would need several sets to make it worthwhile.
Regards,
Andrew
P type drums
NA 0279
PA 1294 |
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George Eagle
United Kingdom
3228 Posts |
Posted - 24/05/2017 : 10:26:13
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Hi Andrew
When I rebuilt my NB I used new steel brake drums which were very effective - I think the wheels would have locked if I used the hand brake in an emergency stop!
By contrast the drums on the L2 probably need skimming as they are not nearly as good as those on the NB - I had to push really hard on the pedal and use the handbrake when having to make a sudden stop due to a traffic problem.
I have ordered a new set of Alfin drums which should be ready shortly. A friend has a set of Alfins on his supercharged XPAG engined TA and is very pleased with them.
George
L2023 |
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JCB
United Kingdom
384 Posts |
Posted - 24/05/2017 : 11:24:11
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Andrew and Forum:
If you ruttle about on the internet there are various options.
As you are based outside of the UK ;your local route would be the best place to start.
I have a set on a t-type they look good and work very well.
On the down side they were heavy(I collected them) and not cheap.
So 12 inch will be heavier and cost more too.
I have never regretted the purchase.
All the best.
John Bakewell |
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George Eagle
United Kingdom
3228 Posts |
Posted - 24/05/2017 : 18:05:47
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The standard steel 12 inch brake drums are certainly quite heavy, I would expect the Alfin drums to be lighter?
George
L2023 |
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Andrew Fock
Australia
370 Posts |
Posted - 25/05/2017 : 21:20:35
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Possibly,but the aim was to have drums that are indistinguishable from the original but stiffer so that the braking is improved.
Andrew
NA 0279
PA 1294 |
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Oz34
United Kingdom
2495 Posts |
Posted - 25/05/2017 : 23:48:36
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Oliver will correct me but I thought his J2 ones were cast iron and that this was preferable to steel as being more rigid?
George, I'd be very interested in your experience with the Alfins when you've fitted them. Also, seeing the comment recently that they should be left unpainted, have you been told that?
Dave |
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Oz34
United Kingdom
2495 Posts |
Posted - 22/10/2017 : 15:36:48
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Hi George (Eagle), it's nearly 6 months since you said you had ordered a set of Alfins and I wonder if you now have any experience of them?
Cheers,
Dave |
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Hamish McNinch
United Kingdom
108 Posts |
Posted - 22/10/2017 : 23:57:37
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quote:
Originally posted by Andrew Fock
Possibly,but the aim was to have drums that are indistinguishable from the original but stiffer so that the braking is improved.
Andrew
NA 0279
PA 1294
Hi, Andrew,
I'm wondering what you you mean by 'stiffer'. And, consequently, what improvement to braking you are expecting. |
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Andrew Fock
Australia
370 Posts |
Posted - 23/10/2017 : 07:55:36
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Hi Hamish,
One of the problems with the original drums is that they flex / distort under heavy breaking. If more rigid drums are used (such as the ones on my P type) then the application of increased pressure cannot distort the drum and the brakes work far better.
This thread was a while ago. Since then I've bought a set of new drum from S&V for the N type so we will see how they go when they are put on.
regards,
Andrew
NA 0279
PA 1294 |
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gordclark
Canada
170 Posts |
Posted - 24/10/2017 : 03:09:22
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My PA is the first car I have even owned with which I have some misgivings about braking. Here in North America, we have had high-speed motorways since 1947, and by that time, cable brakes were something unheard of. I too am concerned about even a brand new set of cables, stretching and degrading on even the first hard stop. And this is just one of several factors that could come into play.
I just don’t have the experience to set them up. But irrespective, I'm sticking with the cable brakes, as I simply don't have the knowledge, the money and certainly not the patience to engineer a new hydraulic braking system for the PA.
Bob Grunau, well-known to this forum, manufactures the “Alfin” brakes for the T-Series. He has carefully engineered an excellent product and ha sold many; and I‘ll bet that given the time, which I seriously doubt he has, could also engineer a hydraulic 12" brake kit to fit most of our MMM MGs.
But I can only imagine that designing an entire brake system, is not for the feint of heart. And would likely, carry some sort of responsibility.
Gord Clark
Rockburn, Qué. |
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gordclark
Canada
170 Posts |
Posted - 24/10/2017 : 03:09:33
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My PA is the first car I have even owned with which I have some misgivings about braking. Here in North America, we have had high-speed motorways since 1947, and by that time, cable brakes were something unheard of. I too am concerned about even a brand new set of cables, stretching and degrading on even the first hard stop. And this is just one of several factors that could come into play.
I just don’t have the experience to set them up. But irrespective, I'm sticking with the cable brakes, as I simply don't have the knowledge, the money and certainly not the patience to engineer a new hydraulic braking system for the PA.
Bob Grunau, well-known to this forum, manufactures the “Alfin” brakes for the T-Series. He has carefully engineered an excellent product and ha sold many; and I‘ll bet that given the time, which I seriously doubt he has, could also engineer a hydraulic 12" brake kit to fit most of our MMM MGs.
But I can only imagine that designing an entire brake system, is not for the feint of heart. And would likely, carry some sort of responsibility.
Gord Clark
Rockburn, Qué. |
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Dolts
United Kingdom
1128 Posts |
Posted - 24/10/2017 : 07:47:23
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Hiya,
Interesting to read the concerns on cable brakes. Degrading and stretching I m not really seeing this on the PB.
My brakes are what they are, but they seem to be getting better. Even locking up at cadwell. I think the rears probably need some work interns of adjustments but my front cables were new about 8 yrs ago. They are probably just about bedded in now!
Apart from a good clean out of the drums at the end of the season I can't see any uneven wear or hot spots. They have had a hard work out this season
i guess my expectations are now set for what my brakes can do.....just what are you trying to achieve?
Mark Dolton
www.triple-mracing.com
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Andrew Fock
Australia
370 Posts |
Posted - 24/10/2017 : 08:20:05
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Hi Gord,
there have been several articles on setting up the brakes. On my P type I can lock them on the pedal... so one cant really expect more than that. There are two main n"secrets"...
1. Use engineer's blue to make sure that the shoes are in contact, file away the high points until you have 80%+ contact.
2. Buy a scale that you use to weigh luggage. Put the car up on stands and pull on the hand brake one notch. Attach the scale to the top of a spoke and pull the wheel forward measuring the "weight" or drag. Measure the drag on each wheel and adjust the cables at the wheels such that they are all even. If you want some bias to the front this is easily included.
Assuming that there is no oil in your rear drums the car should stop pretty well.
Andrew
NA 0279
PA 1294 |
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Ian Bowers
United Kingdom
937 Posts |
Posted - 24/10/2017 : 09:35:04
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There is no reason why the material in cable brakes should be taken beyond the elastic limit and therefore stretch. Certainly when first installed, all of the component pieces will 'bed down' over the first few operations, and may need to be given a final adjustment. After that wear in the shoes will create need for adjustment.
Occasional inspection, particularly at the ends of the shielding, for fraying is vital, but stretching should not be a worry.
Ian Bowers
OD 6791
J3 3772 |
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George Eagle
United Kingdom
3228 Posts |
Posted - 24/10/2017 : 10:05:33
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Hi Dave
I have now got the Alfin brake drums but have not yet fitted them as I have been busy on other things including the traction engine!
I did offer one up and found I will need to slacken the brake cables right off and then take a bit off the lining. When fitting the old drums I found the new cables were a bit on the short side as with the new linings I had to take up very little slack
Alternatively the solution might be to take a small piece off the cable outer cover but I am not too keen on the idea. Has anyone else taken this course?
The drums are much lighter, look to be very well made - see attached photo. The advice is to keep the drums in good order by using WD40 but wax polishing them might be a good alternative. How do K type owners maintain their drums?
Each drum has two 5/16 inch tapped holes to assist in removing them at any time.
George
L2023
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Edited by - George Eagle on 24/10/2017 10:14:03 |
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Oz34
United Kingdom
2495 Posts |
Posted - 24/10/2017 : 15:24:19
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Thanks George, They certainly look very nice! I'll be very interested to hear how you find them in use....I guess they'd stop the traction engine really well?
The other thing about them is the finish. Someone said a while ago that the suppliers advise not to paint, and your comment on WD40 seems to suggest that, assuming they don't want you to put it on the friction surfaces!!
Cheers,
Dave
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