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MG MG Y Type - Brakes on a YA Dumb idea or what?

I've just acquired a front brake set from a MGA 1500 and wonder if it is possible to retro fit to my YA. The shoes are approx 0.25" wider and 1" bigger in diameter than YA, the backplate fits onto the YA swivel pin.
The drum fits comfortably within the wheel and without actually fully assembling, the whole assembly seems to fit nicely, although it appears the setup would widen the track on each side by about 0.5" There possibly would need to be a spacer shim between the front hub and the drum
I recognise that the drums would need to be re-drilled to suit the 5 stud YA hubs and 16" wheels.

Machining parts to complete the setup is not a problem.

Is this a really dumb idea? would I need to upgrade the master cylinder to cope with the TLS setup?

I'm also considering fitting a brake servo, any ideas for the best place to mount it? There isn't enough room on the bulkhead so it will have to go somewhere else under the RHS front mudguard looks promising.

Any thoughts would be very much appreciated.

Regards
David
D P Jones

Hi David

It is up to you but personally TLS vs SLS - if the brakes are properly adjusted and in good condition you really wont notice a heck of a lot of difference. I would leave it alone personally and direct my time and money elsewhere. The brakes on a Y and Y/T (and YB), when properly maintained and serviced are perfectly adequate provided you drive appropriately and do not under distance yourself.

Paul
Paul Barrow

About 30 years ago I fitted MGA 1500 TLS 10" drum brakes all round on my TD (originally TLS 9" drums). The master cylinder was not changed (same 7/8" bore as the MGA twin M/C), and although the original brakes were very effective, I can now stop almost as quickly as TDs with front discs. Slightly wider radial tyres probably help as well. The Y is heavier than the TD, but going from 9" SLS to 10" TLS I would think you would find a vast improvement. A servo sounds interesting - I don't think it would improve the braking, just the quality of control.
R A WILSON

Hi Paul, thank you for your useful comments. Yes, I agree with you that YA brakes are perfectly adequate for the time the cars were built. In fact when I had the car MoT tested, the examiner was very complimentary about balance and efficiency. I regularly leave a good stopping distance between me and the car in front, but very often I get cut up, particularly when approaching junctions which reduces the distance I have to stop in to a worrying distance, I have no wish to "rear end" a "Wally Wagon" (Shiny 4x4 driven by a Wally) so any improvement would be a bonus. I understand that the YB setup is superior to the YA.
So, at the moment I'm keeping an open mind.
Best Regards
David
D P Jones

Had a rethink - a servo would improve the braking and quality of control.
R A WILSON

Not sure Dave but will the mod effect the front rear balance, I have an idea that its around 60/40 in favour of the front so preventing the rear locking up first. Correct me if I'm wrong but that given a certain coefficient of lining friction the braking is dependant on force applied, so perhaps a servo on the existing set up may give better results. As I said before in the past one could vary the braking by selecting another grade of lining but in doing so traded high speed anti fade for low speed response. I think the original Y type road test demonstrated 1G or 30ft braking distance from 30mph which even today is pretty good, for sure the passenger's would get badly shaken. Bryan
B Mellem

I'm up with Paul's view, but would also add, would any future modifications have an impact on whether a car needs an MOT? There was mention of if a car had been modified it may not be MOT exempt.

Secondly could future government changes along the lines of adding regulations which will further restrict the use of those cars that have strayed away from factory specification. I guess we do not know yet, but worth consideration.

The reality is, the brakes were designed for the car, and work fine, drive within the capability of the age of the car, and I don't think you can go far wrong, as they said to the class of students on the recent course I undertook, the best safety device is the steering column, if you're in an accident it's likely to impale your chest therefore my guess is most drivers take suitable care to avoid sudden braking and leave a gap travelling at reduced speed in comparison to modern car travelling on Motorways and A roads, in heated car, with air bags offering false security and ABS braking.


Richard
R E Knight

Richard
You might be interested to know that the South Australian Govt has changed (as of 1 July) their rules on Conditional Registration of vehicles over 30 year old, to allow for modification.

Previously Conditional Rego was only allowed for unmodified vehicles (ie could not install a CD player or aircon etc, let alone improve brakes, handling etc)

Conditional Rego is only available to members of Car Clubs.

Personally, I think the change was to get those cars sitting in garages and sheds on the road and therefore the Govt extra Rego fees.

Stuart

Stuart Duncan

Hi David,
I have driven Y's with standard brakes and various modified setups including boosters and TLS.

Once you go to TLS you need to be running radial tyres as you will simply lock up bias plies and then you have no steering as well as less brake control.

A booster only reduces the required pedal pressure for a given braking application - it won't affect the balance.

If you go to TLS, you need to calculate the required master cylinder to suit as you are pushing two front cylinders rather than one. The sizes of the two have a bearing related to the size of one - if the two had the same AREA as one it will be fine - if not you will need to adjust the MC size to maintain the same pedal travel for braking effort.

Any change to MC size will also affect rear brake performance, so what you say ? - remember with TLS on the front there is only one pair of shoes that work well in reverse - do you ever park on a steep hill or reverse out of a steep driveway, then you need those rear SLS brakes to work just as well as when they were designed in 1947 !.

Best of Luck - but whatever you do, keep drivin ya Y !.

Tony
A L SLATTERY

Just to add a little history to motoring. Our cars were driven mostly by men and for good reason, there was a term 'standing on the brakes' which referred to emergency braking and meant just that. In our much enfeebled age we are unaccustomed to using brut strength when motoring but then anyone braking a Lagonda from 110mph on friction dampers needed plenty of it. Lorry drivers were man mountains what with direct steering and manual brakes. When I purchased my Y in 1960 I was puzzled to find the drivers seat runners cracked, well it didn't take long to solve the mystery. Bryan
B Mellem

I thought with SLS, although there is only one cylinder, there are two pistons, so the amount of brake fluid required is the same as for two separate single acting cylinders. The front to back braking ratio will be affected, as with TLS 10" front brakes they will be far more effective. However, my modern Peugeot has very efficient discs at the front, but rather small drums at the rear, but the system works very effectively. Although the original braking system may have been designed for the car, MG still went to TLS at the front for the YB, with the handbrake still only, as normal, on the rear brakes.
(As I previously mentioned, my TD M/C for 9" brakes is the same size as the MGA M/C for 10" brakes).
R A WILSON

See attached, after a search on Google, from 2016. Perhaps you could try this before you make up your mind about fitting the MGA 1500 front brake set.

R A WILSON

Hi Everyone, I'm still keen on the idea, I have discovered a couple of people who have done something similar so I'm making contact and get their opinion as well.

But firstly, I'll contact my Insurance company and get their reaction.

So thank you all for your help and advice
Dave
D P Jones

Dave,

One thought your comment made me wonder, is if each of the classic car insurers have a acceptable standard? i.e. if one may be okay but others not okay with certain modifications then you would be stuck with the one who would offer the insurance. I was reading the article on letters page of this months edition of practical classics, and it made reference from one reader, asking why in September's month one of the articles suggested keeping cars to original spec and then in October's edition it suggested suitable modifications for the cars. The problem with modifications is where do you stop?

Richard
R E Knight

Obviously you should talk to your insurance company, but you will probably not get a reduction in your annual payment, despite proposing to improve the braking of your YA.
R A WILSON

Maybe I'm missing something here. I thought people bought classic cars to experience the joys of motoring in bygone days.

I do not understand why owners want to modify their classics to make them like modern cars. I agree that improved lighting, especially at the rear is necessary for safety in modern traffic, but if you want a car that drives like a modern one, why not buy a new one. They are cheaper to both buy and maintain and more less polluting.

Mike
M Long

My wife and I watch a TV programme called 'Back in Time for Dinner' where a modern family attempt to re-enact a period from the past, It is easy to pick holes in little errors in but it is clear that the participants and production team have not the slightest idea of the mind set of the period. Daughters in the past were expected to help so that the mother could pass on the very great knowledge of house craft and food preparation with what was at that time available.
My point is that modern motorist do not have the skill in handling early classic cars. I give for example my first motor cycle a Triumph Tiger 70 fitted with friction damped girder forks and rigid rear frame. I frequently rode this machine near its 75mph maximum, I knew instinctively when a speed wobble could occur, and the braking performance on various road surfaces, I was constantly aware of iron man hole covers, changes in camber, slippery patches on the road. So I was well prepared for my next purchase a 100mph Scott motorcycle. When time and finances were right for my change to motoring I purchased a 1948 MG YA and was able to apply these skills to driving and so that is why I don't need servo or disc brakes.
These skills can only be gained from experience, my advice is just don't expect the car to perform anything like a modern one. Bryan

B Mellem

Hello every one, my idea is not based on the desire to upgrade her to modern (ish) standards and yes I am very well aware of the cars limitations and foibles, as I have been driving her for over 45 years and so far this year have done over 7000 miles including Brooklands, Spring Run, Oswestry, Gear Dorset Steam fair and the Isle of Wight. Each a round trip of 500 miles or more. plus many many local trips, like New Cairnes, we use the car for everyday trips as well, shopping etc. On our roads we are perfectly content to drive according to the conditions and safely. However, the main reason for my thoughts on this potential upgrade, which will be in period for the car, YB having TLS and regarded as better than the YA is to give a margin of safety when other drivers who have not got a clue about Classic/Vintage cars performance drive idiotically.

In this day and age it is virtually impossible to drive anywhere without encountering trunk roads which are very busy and modern drivers want that space I've left in front to allow for the extra stopping distance a cut me up usually on the approach to a roundabout. This seems to happen more frequently in recent years.

The worst offenders seem to be visitors to area, (summer holidays etc.) in shiny 4x4 they tend to be quite arrogant in their attitude (some, but not all I might add). Some of them don't seem to have a reverse gear when they encounter another car on a narrow country lane, with passing places.

Yes, I do have some non factory fitted modifications fitted, flashing indicators (still retaining trafficators with flashing LED) and LED rear lights and brake lights (period) windscreen washers all intended to improve safety and enjoyability of the journey.

Apologies for the whinge, but I felt it appropriate to clarify my thinking.
Dave
D P Jones

This arrogant dangerous driving on the road you refer to Dave is the main reason I sold the TF even with its TLS brakes, just about every time we ventured out there was a serious incident. May I suggest a 'dash camera' mounted on the rear window it indeed works wonders on my modern car, As soon as that clown driving close behind realise they are being recorded they back off, it always works, also they fear you may have a camera on the front as well. These cameras don't cost that much and they are a great aid for safety. Bryan
B Mellem

I'm in M Longs camp, i go to classic car shows and most cars are as built and the owners are pleased and want to have it that way. I do wonder a little if all these wanted braking mods on ys etc are due a little to the failing reaction times and strength of leg of some drivers as they get older yes lights i can understand nothing else though. It has long been known that if you turn these classic cars into modern compliant cars you stand a good chance of losing the tax and mot concessions plus cheap insurance.One other thing has any one seen the YB sedan on e bay a rare botch up or words to that effect.
John YB0362
JC Jebb

picture of sedan

JC Jebb

Hi Dave.
I fitted a servo to my YA when I carried out a full body off restoration, I used a MGB servo unit and mounted it on the inside of the fire wall on the passenger side behind and below the glovebox. I found it to be a useful addition to the braking system. See attached photo.

C A Pick

Assuming your car has a central battery** box, could the coil be moved, and a servo mounted in its place. There would be no need to run pipes through the bulkhead, and the coil could go to the position it has with the offset battery box. If your car has an offset battery box, there would be insufficient room to do this.
** or is it a tool box?
R A WILSON

Just bumping this thread to active for Gav.

Tony
A L SLATTERY

This thread was discussed between 10/11/2017 and 21/01/2020

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