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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MG Y Type - Master Cylinder

I have just purchased the what I believe is the only YB in New Zealand.
I'm having fun in the shed at night tinkering away checking off some frustrating electrical faults.
Today on a drive I lost the brakes, pedal went to the floor. After some bleeding tonight I have found if pedal pressed slowish it will go to the floor but if pressed hard and fast it is good. No signs of fluid leak at any wheel.
I'm thinking master cylinder.
Where do you guys suggest I buy a new cylinder and/or a rebuild kit in the UK?
Also what other cars have the same cylinder?

Thanks
K Weeds

https://www.mgbits.com/contents/en-uk/p4974_Master-Cylinder-Brake.html

Same as TD / TF is the YB M/Cyl.

The YA/YT is rarer of the two master cylinders fitted to the Y type cars.

MG Octagon worth checking too.

https://ccparts.nl/en/ are who I recommend for advice, though long long way to your location in NZ.

best of luck

Richard
Richard Knight

Thanks Richard, that's a great help.

Kevin
K Weeds

Kevin

A useful source source of good quality Lockheed and Girling brake master cylinders is Powertrack Brakes: https://www.powertrackbrakes.co.uk/

Looks like yours may be a Lockheed designed master cylinder and system? (I.e. not Girling).

When I was looking for a master cylinder for my MkII Austin Healey Sprite they could supply the rarer model I needed and importantly made by the original manufacturer (which was a Lockheed cylinder which is now ‘920 Engineering’, before that ‘’Caparo’ then AP Caparo’, then ‘Automotive Products/AP Lockheed/AP Lockheed Girling/Lockheed Girling’ etc and years ago just ‘Lockheed’ when this was a separate company from Girling. I had concerns about quality of aftermarket components e,g. TRW.

Other useful suppliers/repairers of hydraulic brake and clutch master and slave cylinders:
Coasting Limited http://www.coastings.co.uk/
Past Parts https://www.pastparts.co.uk/

Makes me think if your master cylinder is needing replacement - why not fit a good quality new slave cylinder and some/all replacement lines while you are doing this? New copper brake pipe kits for specific cars and models direct from manufacturer: https://automec.co.uk/a/find/?nullsMake=MG&step=1

Keep the old master cylinder for spares/reference purposes and if you ever need to have it rebuilt. Note there may be expertise in NZ to rebore master cylinders, if I remember correctly companies in Australia can do this.

Cheers
Mike

M Wood

Kevin

If the master cylinder is 7/8 inch diameter then this looks like the genuine item:
https://ccparts.nl/product/master-cyl-s-orginal-ap-lockheed/ (ask Powertrack too if they can supply) AP Caparo/920 Engineering part number LK88187.

Lockheed Delphi LM15325 (could be made in Italy) might be OK if cannot get AP Caparo/920 Engineering, but I would prefer AP Caparo/920 Engineering. I would avoid TRW or unbranded.

Thanks
Mike
M Wood

M Wood thanks for your input.
I haven't removed the old one yet so not sure, perhaps I should jack it up and have a good look.
I was planning on waiting until a new one arrived, which probably take several weeks, and do it all in one go.
What concerns do you have with the unbranded and TRW options just for curiosity?

Ta
K Weeds

Is this an original?
Looks like its a 7/8th.

When replacing it do I need to open up the box in front of the cylinder or is as simple as it looks?

Ta

K Weeds

Hi Kevin,
Rather than buying new and being unsure of the quality, I strongly recommend you have your original cylinder re-sleeved in Stainless and fitted with new seals.

Your symptoms sound like the seals have gone hard with age.

I use "Knights Old School Brakes" in Brisbane Australia (they are on the website suppliers page). I would also suggest you send the wheels cylinders to them as well as it is false economy to do only part of the hydraulics. Perhaps someone in NZ offers a re-sleeving service ?.

The YB is certainly a rare model down this way - only 5 cars known in Australia.

You will find plenty to do on the car while the cylinders are away.

Safety Fast

Tony Slattery
The Classic Workshop
Black Mountain QLD
Australia
A L SLATTERY

Thanks Tony, I'll consider all that.
I have been tinkering away and thought I had most of it covered until the brakes. No big deal when it happened as I have 3 Model T's which I drive regular so plenty of experience driving with little to no brakes.
There are places in NZ that offer the stainless option.
I believe this is the only YB in NZ.

Thanks
Kevin
K Weeds

Well I removed the cylinder, I see it had a silicon fluid sign above the filling cap and on inspection the the cylinder looks fine and just a kit is required. I guess the silicon fluid done it's job as there is no signs of pitting.
I ordered a kit from "MEV Spares" in Kent on the 20th, they have taken payment but I can't get them to respond to any emails and no tracking info has been supplied so not sure what's happening there.
I'm keen to get roadworthy so I ordered another set from "Past Parts", hoping they will be more efficient.
Then tonight I found a US company "Moss Motors" which had excellent info showing clear pictures of the internal parts as the cylinders changed over the years, this enabled me to order the exact rebuild kit that my cylinder required, plus well priced silicon fluid so I've got that coming also. Surely one of these 3 suppliers can front up lol.

K Weeds

It certainly sounds like you're doing the right thing by overhauling the master cylinder - if silicone fluid has been used since the last rebuild there should be no corrosion of the cylinder bore, and it's likely that, as others have said, the seals have aged. Recently-made new seals will be entirely compatible with silicone fluid (a few years back they weren't) so you should be back to efficient braking soon. But it's probably a good idea to look at the wheel cylinders too - they're not hard to get at and strip.

I'm not sure I've heard of MEV in Kent (I'm in the UK) and would go to NTG for parts like this - they stock good quality parts and I've found their service very good since about 1977....
Tim Griggs

K Weeds

Moss motors sells parts for MG TD/TF etc. but as far as I am aware does not sell master cylinder parts for the YA/YT master cylinder. What part number are you looking at on their site?

The IMGYTR only recommends C&C in Holland for repair and refurbishment of YA/YT Master Cylinders for good reason - namely that I have found a number of companies over the years who CLAIM to be able to do YA/YT master cylinders ... and then have been found wanting. I still ship YA/YT master cylinders from the US to them (C&C) and am never disappointed. Yes they are expensive ... but then arent your brakes worth a couple of extra $?

Paul
Paul Barrow

Thanks guys,
Well I looked online again and found a company in NZ that looked promising and when I rang they had 3 kits in stock! So I ordered one (4th kit ordered now) plus they had silicon brake fluid at a reasonable price so I ordered and it arrived in 24hrs to my door. Unreal.

Over the weekend I gave the cylinder a quick hone, fitted the kit and they bleed up perfect. In fact now the wire wont operate the brake lights due to the pedal being higher. Is there only the one pedal height adjustment that's on the shaft going into the master cylinder in that devil designed pedal box?

Then on Monday my moss motor parts arrived. Excellent price for silicon fluid from them $29us for a quart! Plus the exact kit I needed.
Paul they do stock YB parts if you look hard enough, what I liked about them is they show a photo of the internals of 3 different master cylinders of the era with the part number to ensure you select the exact parts to suit yours (as long as you have yours apart to reference).

https://mossmotors.com/media/instructions/180-730.pdf

PLUS their airmail postage I selected (their cheapest option of 3) was only $15us.

So NZ order 1 day - perfect
Moss Motors in the USA - 13 days, for only $15 I'm happy with that
Past Parts and Mev spares has been over 20 days, still nothing. I don't mind the delay if they would just email if there is a hold up AND then tell me when they have been posted.

I guess I will some spares if they ever arrive, no biggie as these bits fit a lot of English vehicles of the era.

I have 3 Model T Fords and having no brakes on the wheels has its benefits lol.
K Weeds

This thread was discussed between 16/07/2021 and 11/08/2021

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