How do you get that master cylinder nut off?

[StLouisSinger]

There is a big nut on the end of the master cylinder. How do you get that thing off? I soaked it in penetrating oil and used a good size breaker on a good size wrench, but it is not going anywhere. If this were on my boiler pipes I'd heat it up with a torch,then put a 3 foot breaker on an pipe wrench and beat it with a hammer till it came off. For some reason I think this is not the correct thinking for this situation. Is there a trick to getting this off?
Thanks in advance,
Tom

[mikeyr]

its just super tight and heavily corroded, you have to fight it off if you need it off. You can rebuild the cylinder without taking it off, you only need it off if you have to re-sleeve the master.

[StLouisSinger]

Mike that is good to know. I thought I would need to remove that nut to replace the main seal. When I inspected the master cylinder there was NO main seal in it. There was just a low pressure seal on the end of the piston closest to the push rod. The other seal was just gone. So I guess it is in pieces clogging the rest of the system. SO I plan on replacing all the brake lines I assume they are steel and ready to go anyway . I requested the Australian Scientific Magazine from Gene and he has been very nice about looking into it. I am realizing that the Singer Service Manual I have is of no help and must not be for my car. It says it is for the Hunter and SM 1500,and the brake info is useless. The master cylinder info is from some other unit completely. I was given the manual when I got the car. I see the UK Singer Owners Club has both a "workshop manual" " and an "instruction book and repair manual" that are for the 4AD.
http://www.singercars.com/linkout/outli ... ine.co.uk/
I'm sure I should have one of these or both of them instead of what I have.
Frustrating to have the car out of commission again. But it did make the 20 mile (round trip) journey to the all British car show where it won 3rd place in it's division. That is 3rd out of 4 cars but I'll take it!
As I told my father-in-law this Singer has not driven more than 10 miles in the past 30 years so that 20 mile trip represented 60 years of average driving.
Tom
1952 4AD

[Paul Bouchard]

Tom,

WOW! 60 years of driving in one day. Impressive

The SM1500 can be a confusing moniker. In the US (and Canada) the 4AD was often referred to as the SM1500 but there was also a all-metal saloon by the same name. They shared a very similar engine and I guess that at the time the British are all about series numbers, those of us over here were about size and power. You are correct about the brake lines - they are steel. I found that there were standard fittings in the local car parts shop (Canadian Tire), off the shelf. I brought a spare wheel cylinder to make sure that I got the right stuff.

Kudos for getting a hold of Gene. The library has quite a few useful books in both scanned and printed versions. I have the Scientific Magazines book is not bad... not perfect but not bad. While you are waiting for the club library version, and if you are interested, I have scanned the brakes section. The file (PDF) is not bad, a bit grainy, and only about 400kb (small enough to send via e-mail). If you want this (5 pages or so) then e-mail me at:
paul_bouchard@yahoo.com and I can send it over.

Have fun!

Paul

[mikeyr]

do you have this PDF http://www.singercars.com/4ax/motortrader.pdf ?

I rebuilt my 4AD with it back in the late 70s

[StLouisSinger]

Thank you all for the support. The nut came off with nothing more than a good pull on a three foot pipe on the end of my biggest Crescent wrench. The biggest problem was keeping the master cylinder in the vice and keeping the vice from being ripped off the workbench. Once I stabilized everything it was not so bad. Also let it be known that Dave Green is the greatest!
He got me going with the right master cylinder kit and we figured out that for what ever reason my master is a 3/4" bore and not the same as the stock Singer 4AD 5/8" bore. I see the style master cylinder found on the 4AD is the same as that found on the Austin Healey 100-4 and it has a 3/4" bore. So I am assuming it originally had the 5/8" bore and was replaced with this 3/4" MC at some time.
Back to the big nut...Once the nut on the end of the master cylinder was off I could see that the main seal was still in there. It just was impossible to see from the other end. Also that main high pressure seal is held in place by a shim on the piston side and a retaining ring on the nut side. So that main seal is wedged in there tight and there is no way to remove or replace it without pulling that nut. I took some pictures of the disassembled master. You can see the order of the pieces. I tried to lay them out in some kind of order.

IMG_1309.jpg (22.47 KiB) Viewed 2991 times

This is how the parts would line up inside the master from top down: grey metal shim, rubber seal, metal crown like seal support and at bottom copper washer.

IMG_1323.jpg (26.96 KiB) Viewed 2991 times

Here is a view inside the master from the nut end.

IMG_1324.jpg (26.51 KiB) Viewed 2990 times

Here is an exploded view of the whole thing, click to enlarge.

Just thought as long as I found all this out I might as well post it while it was fresh. I'm sure everyone is finding this 101 stuff. But I want to contribute what I can to the knowledge base.

[Paul Bouchard]

Nicely done, and great photos! Dave is the man when it comes to parts and the interchange. Mike too had a 4AD for quite a long time so should also be good to help out. My experience is just from one car, but the memories are still fresh. Between everyone there should be some good info.

Healey brake parts seem to be quite abundant on the 4AD... well the front ones anyhow. Good luck with the brakes and let us know how it goes.

Paul

[Peter McKercher]

Tom
Well done. It's this sort of explanation with photos that really helps out other members