How good should our brakes be?

[Clive]

Which reminds me....

If there is a bit too much play in the front wheel bearings this can cause pads to be pushed further back, requiring more pedal travel. And I gather many of the brand new calipers sold are incorrect where the seals sit meaning they pull the pistons back too much. (for goodness sake, Girling etc got this stuff right decades ago, how can they get it wrong now? not as if it is complicated)

[Pete Lewis]

and i would add use steel anti squeal shims not any of the plastic based squidgy stuff thats often included in pad kits 

stiff pedal linkages that restrict pedal full return will affect pedal travel as the recoupe port is left closed  and makes bleeding hopeless

Pete

 

[dougbgt6]

Yes chuck the squidgy stuff away, I still have the original metal anti squeal shims, looking a bit tired, but still work.

Doug

[JohnD]

The "warped" disc may be a myth, when the symptoms of juddering are due to the transformation of the autenitic cast iron of the disc into cementite, iron carbide, very hard with a high frictional coefficient.    See Carrol Smith on this: https://www.brakes-shop.com/brakepedia/general/myths-of-the-braking-system

Heating the brakes to their maximum working temperature, as  bedding in is intended to do, and then allowing the disc and pad to sit close together so they stay hot for a long time, can start this process.

JOhn

[Mjit]

On 27/04/2020 at 11:22, Pete Lewis said:

never forget the bedding requirement  its simple 

2) Following Bedding Procedure for M1144 / M1155 / M1166 initial brake test start with 3 – 4 light applications from 30mph down to 0mph. 

After these, follow the steps below according to Material. 
 
M1144: 6 / 7 medium pressure applications 70mph down to 30mph

This is a great theory but I'd question its practicality, unless you happen to own a private road/race track.

1. 3-4 light applications from 30mph down to 0mph.  OK, might be able to manage this one, though would have to be careful about what time of day so my road is quiet-enough to do it without someone driving in to me.

2. 6-7 medium pressure applications 70mph down to 30mph.  Humm.  Well I live in London so no roads near me where 70mph is safe, so looks like I need to drive on old pads to near a motorway, then change the pads at the side of the road.  Even then I can't help feeling trying this on the M25 would end up being "6-7 medium pressure applications 70mph down to 30mph, or until an lorry plows in to the back of you at 56mph".

[Pete Lewis]

with any brake testing out on the open roads  you really do need to keep your wits about you on whats around you , common sense works

after a refit or layup   they may just need to give a Italian Tune up and give them a good bedding but use eyes and ears mirrors and vision

to keep you and others SAFE

Pete

[Colin Lindsay]

15 minutes ago, Mjit said:

This is a great theory but I'd question its practicality, unless you happen to own a private road/race track.

1. 3-4 light applications from 30mph down to 0mph.  OK, might be able to manage this one, though would have to be careful about what time of day so my road is quiet-enough to do it without someone driving in to me.

I'm the other extreme at present, thanks to lockdown. I was having a coffee outside earlier and there were two cars passed in all that time. We have two little... I'll call them Yahoos - one half a mile from me countrywards and the other about a quarter mile in the housing estate, in the opposite direction, who regularly work on Clios, Hondas and the like and use this road as a test track between each other's houses. I reckon none of the cars are taxed, insured or even roadworthy, but I hope the neighbours know it's not me and my Triumphs making that racket...!  

[yorkshire_spam]

Bit late to the party here, addressing the original question "How good should our brakes be?"....

The brakes on the Dolomite by default are utterly woeful. With an automatic in winter on heavy choke you have a job just preventing the car from moving off on it's own. But with the TrackerJack conversion they are GREAT! But that's a bit of a diversion/distraction.

My Spitfire on the other hand... when I bought it the MOT was 2 days old and when I drove it home the brakes were lethal. Seals in the master cylinder were shot. So I rebuilt using a branded rebuild kit (At the time in 2012 it cost me about 20 quid for what I think was a lockheed kit from the local motor factors) 
Since then I've put on new standard solid discs and Mintex 1144 pads in the standard calipers.
The pressure required on the pedal is more than you'd expect if you compare with a modern, but certainly not excessive. Stopping power is limited by road surface, conditions and tyres - not the brakes anymore. On a good surface with good brand tyres if you apply the brake right you can make the passenger headbutt the windscreen. On mountain passes I tend to drive careful, but never had fade issues on the long descents. Not sure about bigger heavier cars, but well fettled brakes with mintex 1144 pads are more than up to the job in something with the mass of a Spitfire. My MOT tester always comments on how good they are for the size of the car.

[ludwig113]

7 hours ago, Mjit said:

This is a great theory but I'd question its practicality, unless you happen to own a private road/race track.

1. 3-4 light applications from 30mph down to 0mph.  OK, might be able to manage this one, though would have to be careful about what time of day so my road is quiet-enough to do it without someone driving in to me.

2. 6-7 medium pressure applications 70mph down to 30mph.  Humm.  Well I live in London so no roads near me where 70mph is safe, so looks like I need to drive on old pads to near a motorway, then change the pads at the side of the road.  Even then I can't help feeling trying this on the M25 would end up being "6-7 medium pressure applications 70mph down to 30mph, or until an lorry plows in to the back of you at 56mph".

Yep i have the same problem, inc the M25.

I tend to go by the motto, " little and often" for any pads the first day to bed them in properly and then make sure they are warm on day 2 before any heavy braking..... works for me....

When i raced bikes i could bed in a set of pads in 2 laps of Brands Hatch.

 

paul

 

[Herald948]

On 27/04/2020 at 09:16, Colin Lindsay said:

...For a real driving experience try a drum brake Herald; that really makes you pay attention.

 

I dunno; in my time, I've locked up front wheels on all-drum-braked Heralds without Hercluean effort! 😀 Granted, that's not so easy to do after a long descent down a steep mountain road, but.... 😮

[mpbarrett]

You can have very good brakes on a Triumph but you need to pay attention to the details. I think its sometimes the feel that is very  different to a modern, more free play before anything happens usually its just wear and tear of an old system.
Check for corrosion on the front disks, if there is any change them you want the max area for the pads to work on.
Get the rear brakes working correctly (difficult on the late self adjusting GT6 brakes, but possible). 
Make sure the hand brake is properly adjusted and works.
Use new brake fluid if it more than a few years old change it.
Check all the pivot point on the master cylinder to pedal (they wear and will reduce the feel of the brakes as there is more free play), check the brake pedal bearing for wear. 
Bleed the system carefully and get rid of all the air in the system.
Yes to Minex pads, worth paying for.

Mike

[PeteH]

Hi

1 hour ago, mpbarrett said:

Use new brake fluid if it more than a few years old change it

YES, YES, YES, (for those who are not aware) Unless using Silicon fluid. Brake fluids are Hygroscopic, and as such absorb moisture from the atmosphere. When the brakes get hot the water "boils" and the resulting vapour reduces the brakes to "non existing". On cars like ours, especially if laid up, a couple of years can be too long!.

Long story short:- 32ft, 9tonne, American Camper. Down hill (not too steep). NO BRAKES!!. Sh1t!! The longest 5 min of my life (almost). Saved by scraping the speed off with the nearside tyres on the kerbing!!, and pulling the (Auto Box) into lowest gear, and pumping like fury. After half an hour. I got brakes back and drove gingerly to a campsite where I spend the weekend, bleeding DOT4 fluid into empty "pop" bottles having been to Halford's for 5litre of new fluid.

NOT something I wish to repeat!.

Pete

[NonMember]

I boiled the fluid in my recently acquired first car (Vitesse saloon) on the way back from my first TSSC meet in Basingstoke, back in 1988. Tonking along at a fair pace on a country A-road, went to slow for a bend and... pedal to floor, no resistance, no effect. Fortunately I wasn't really pushing the speed and was able to round the bend on-throttle, but I did the rest of that journey much slower and having to pump the brakes any time I wanted to stop. Being young, naive and unaware of the limited life of DOT4, I actually replaced most of the braking system (master cylinder, all pipes, all hoses) before driving it again. Flushing and refilling with fresh fluid would almost certainly have been enough.

[Pete Lewis]

following Doug getting a tester for his raffle I bought one  arguably at £12 cheaper to just change the fluid every two years ,but this was to use at pub meets and check cars in the pub car par on sunny evenings , the results were all in the red at 3 to 4%  it surprised many and some rapid flush through's followed the problem of venting allowing moisture into the reservoir has been a fact for years , and its a fact many change and mess around with all sorts of myths rather than CHANGE the Dot4 

Pete

[Colin Lindsay]

8 hours ago, Herald948 said:

I dunno; in my time, I've locked up front wheels on all-drum-braked Heralds without Hercluean effort! 😀 Granted, that's not so easy to do after a long descent down a steep mountain road, but.... 😮

The biggest problem is driving a variety of moderns all week the getting into a drum-braked Herald. The sheer effort of getting my 948 Coupe to stop on a hill coming down to a t-junction was amazing. My fault; I'd keep the speed up, approach the junction in the normal manner, lightly touch the brakes and... nothing. More pressure, nothing and by now the junction is looming.... so stand on the pedal, make dimples in the floor with the pedal, and the car stops. That was one incident I'll always remember. Sneaky of Triumph to build a twin-carb coupe that was capable of quite good speed, and fit brakes like those...

[dougbgt6]

This was the tester I bought, gone up a bit, £19!

https://www.ebay.co.uk/itm/Automotive-Brake-Fluid-Tester-Oil-Inspect-LED-Light-Sound-Alarm-DOT3-DOT4-DOT5/323364390906?hash=item4b4a0507fa:g:kc0AAOSwDyxblmvg

However, now, there are these £3.89! 

https://www.ebay.co.uk/itm/Car-Brake-Fluids-Tester-Compact-Indicator-LED-Pen-Moisture-Water-For-DOT3-4-5-UK/324145234675?hash=item4b788fc2f3:g:NB4AAOSwvpZeoqDq

Doug

[JohnD]

Perhaps the Club, or Areas, should look out for examples of the old "Tapley" brake meter?   They do come up on sal now and then.  This is a Ferodo branded example:

The flat base is very heavy and would sit in the footwell while you tried to stop the car as hard as possible.        A mass inside would then compress a spring according to your decelleration and cause the dial to indicate how much that was.

There was a smaller version intended to be clamped permanently to a convenient place on the dash, so that you could monitor your brakes!  No doubt very useful for that cable braked Austin 7!

Either, if they could be made functional, would be a useful addition to Club or Area resources!

JOhn

PS  A modern version of the Tapley meter is still available! https://www.bowmonk.com/products/view/tapley-brake-test-meter

And there is a wholly electronic equivalent, the BrakeSafe Classic Brake Test meter:

BUT, it costs £1200!

[Adrian]

Ok back on topic now. I did adjust the rear correctly. I’ve change to the new pistons today, need to bleed yet but found the rear shoes were low, one was just catching the rivet. So if rear braking is minimal in contributing to stopping do I need to be looking at mintex or standard from the club shop?

if the rear is ok, is there anything to be looking out for on the front? No leaks. 

[Pete Lewis]

all rear shoes as far i i can see are std no idea who makes them

only front pads have options of std or mintex

the last set of aftermarket shoes i put on the 2000 were awful  cardboard linings  the dust stuck to the linings like cheap black paint , they came of very quickly and refitted the originals being a woven mix

pete

 

[yorkshire_spam]

19 minutes ago, Adrian said:

So if rear braking is minimal in contributing to stopping do I need to be looking at mintex or standard from the club shop?

I tend to go out of my way to buy ferrodo or similar branded shoes for the back, generally only a few quid more in my experience. But as you say, I'm probably throwing that money away as the rear brake effort is minimal.

 

[Adrian]

Good to know, thanks. Mine are very dusty and only done a few miles since rebuild. I've ordered some anyway from Angie and whilst at it thought I may as well ensure the lines are tip top so a set of automec also on the way. One thing I've noticed but a lot of sites only list the acclaim, dolomite, TR7 or spitfire, I assume the part number is interchangable through som of the range.  What sites other than the club shop do you use? (I'd have thought, rimmers, canley, etc would be generic?)

(I've ordered some anyway from Angie and whilst at it thought I may as well ensure the lines are tip top so a set of automec also on the way.)

[mpbarrett]

I am sure I saw something in an old mag about using a house brick to measure brakes.
You rotated it around put the brakes on and looked to see if it fell over, on its end for min braking on its side for max braking

have to see if I can find the article

mike

[Colin Lindsay]

24 minutes ago, mpbarrett said:

I am sure I saw something in an old mag about using a house brick to measure brakes.

That's the Belfast method. Throw it at a passing car; if he stops in time to catch you, he has good brakes, if you get away, he hasn't.

[Colin Lindsay]

6 hours ago, JohnD said:

Perhaps the Club, or Areas, should look out for examples of the old "Tapley" brake meter?   They do come up on sal now and then.  This is a Ferodo branded example:

An original Tapley, currently 99p on eBay. Anyone in the area want to collect it for me?

https://www.ebay.co.uk/itm/Tapley-Brake-meter/153911287266?hash=item23d5d3dde2:g:3HUAAOSw4ytep0GI

 

[Pete Lewis]

i had one loaned it to a guy who disappeared    never to be seen since 25yrs ago