44 replies to this topic

[b_sdaddy]

sunday here and garage closed. no photos sorry.

 

I know for sure that there are indeed x2 pipes running to the rear so could be this 'friday afternoon' model.?

 

 

As moke spider has found 'like-for-like' replacement for the faulty master cylinder, should I just replace this as well as one of the pipes running to the rear (N/S).?

 

 

first question should be in my mind, what system do you have?

in 1978 they fitted a terrible system as the pressure regulators ran out and everyone was on strike or something so they basically bodged it by running individual pipes to the rear wheel cylinders through 2 t-pieces on the bulkhead and used 1/2 inch bore rear wheel cylinders.

 

its an absolute nightmare as the rear cylinders have a tendency to seize up and its a miracle if you can bleed it properly, my mini is having the whole system stripped out at the moment

Cheers for the info: What's actually involved in stripping out everything and what are you planning to end up with.?

 

Can I just double click on a box and buy a kit on-line.? or perhaps you have an existing shopping list.?

 

 

cheers all!

[b_sdaddy]

 brake cylinder closeup.jpg   97.45K   9 downloads

 

 

cropped this from an engine bay photo.

 

distinguishing feature is wires connecting to main body - tried googling GMC 167 & 227, but have failed to see any piece with wires going to the main body.

 

 

will go and take very close photos, and look for casting numbers or anything that will give the exact details of what unit I have.

 

 

When found, is it worth going for a repair kit first, or just straight swap.? £10 vs £60.

 

cheers

[Spider]

It does indeed appear to be a GMC167 (or the imperial equivalent).

 

I'm not up to speed with your local laws in Belgium, however in the UK and here (and a few other places around the world) front and rear split systems where what the authorities required to make that year model road legal. It could be the case in Belgium that the Diagonal Split - which sounds very much like what you have - is what is required there, so I wouldn't recommend rushing in and modifying it to a front / rear split set up before checking what's required. This could also have an Insurance impact.

 

I have to say, by the time I ever found out the Cylinder (master or wheel) had a problem, they were too far gone just to be able to fit a kit, they really are intended as a maintenance item (I think the brake manual recommends routine rubber replacement every 40 000 km - but who does that?).

 

Why not remove and strip yours down, then you'll be in a better position to see if all that's needed is a kit. 

 

<Edit: for reference, if you need them, the original rear wheel cylinders on your car were 9/16" Bore size, P/N GWC1131 >

Edited by Moke Spider, 27 December 2015 - 08:03 AM.

[b_sdaddy]

OK then, looks like it's a straight 'like-for-like' swap - no upgrade to different system/master cylinder.

 

First check out internal condition but probably will end up replacing the GMC 167 from SomerfieldMini(UK). As you said Moke Spider, it's probably past it's sell-by-date, being nearly 40 years old!!

 

Then replace the single broken pipe, again, like-for-like.

 

cheers and will keep you posted...

[b_sdaddy]

It does indeed appear to be a GMC167 (or the imperial equivalent).

 

I'm not up to speed with your local laws in Belgium, however in the UK and here (and a few other places around the world) front and rear split systems where what the authorities required to make that year model road legal. It could be the case in Belgium that the Diagonal Split - which sounds very much like what you have - is what is required there, so I wouldn't recommend rushing in and modifying it to a front / rear split set up before checking what's required. This could also have an Insurance impact.

 

I have to say, by the time I ever found out the Cylinder (master or wheel) had a problem, they were too far gone just to be able to fit a kit, they really are intended as a maintenance item (I think the brake manual recommends routine rubber replacement every 40 000 km - but who does that?).

 

Why not remove and strip yours down, then you'll be in a better position to see if all that's needed is a kit. 

 

<Edit: for reference, if you need them, the original rear wheel cylinders on your car were 9/16" Bore size, P/N GWC1131 >

MokeSpider,

 

better photo.

 

Could you please, (or anyone else looking), confirm/deny that this is in fact a GMC167. would rather replace like-for-like for several reasons, especially hastle/cost factor!

 

 

Cheers as always,  brakemastercylinder.JPG   36.96K   11 downloads

[Spider]

OK, now we have a better picture of it, it's either a GMC167 or a GMC168.

 

The only difference between these is the threads for the pipes.

 

The GMC167 has M10 x 1.0 mm threads, these are still available and seem to be the most common of the two.

 

The GMC168 has 3/8" UNF Threads and is NLA.

 

You do need to be careful here as 3.8" UNF Fittings will screw in to the M10 x 1.0 threads, but will feel loose, however the M10 x 1.0 Fittings won't go in to the 3/8" UNF Threads (hope that's not confusing!)  3/8" if measure in metric is 9.5 mm and that might explain why they go one way but not the other.

 

While the 3/8" UNF Tube Fittings might go in to the M10 x 1.0 threads, I wouldn't recommend it as if one wants to pop out it will do so suddenly and without warning.

 

OK, how to pick them apart. If you disconnect one of the lines, then try to fit, by hand!,  a good condition and clean wheel nut on to the tube fitting. If it goes on, then 3/8" UNF, if it doesn't, then it's M10 x 1.0 and a GMC167.

 

Also, your Master Cylinder has been retro fitted with a later cap that has a float switch in it. I actually do the same, but be aware that the new Cylinders don't come like that (as they weren't standard that way).

 

Sorry for the long winded post, but I'd like to arm you with the best possible info - we are talking Brakes after all.

 

<Edit: Just one other point, some of the lines, while they may have Metric Threads actually take Imperial Spanners ie, M10 x 1.0 fitting, but a 7/16" Spanner is the correct one to use. I thought I'd mention that because you may assume that it has the 3/8" UNF Threads from the Imperial Spanner bit. I am convinced they did some of these things to drive us totally mad. >

Edited by Moke Spider, 31 December 2015 - 07:08 AM.

[b_sdaddy]

OK, now we have a better picture of it, it's either a GMC167 or a GMC168.

 

The only difference between these is the threads for the pipes.

 

The GMC167 has M10 x 1.0 mm threads, these are still available and seem to be the most common of the two.

 

The GMC168 has 3/8" UNF Threads and is NLA.

 

You do need to be careful here as 3.8" UNF Fittings will screw in to the M10 x 1.0 threads, but will feel loose, however the M10 x 1.0 Fittings won't go in to the 3/8" UNF Threads (hope that's not confusing!)  3/8" if measure in metric is 9.5 mm and that might explain why they go one way but not the other.

 

While the 3/8" UNF Tube Fittings might go in to the M10 x 1.0 threads, I wouldn't recommend it as if one wants to pop out it will do so suddenly and without warning.

 

OK, how to pick them apart. If you disconnect one of the lines, then try to fit, by hand!,  a good condition and clean wheel nut on to the tube fitting. If it goes on, then 3/8" UNF, if it doesn't, then it's M10 x 1.0 and a GMC167.

 

Also, your Master Cylinder has been retro fitted with a later cap that has a float switch in it. I actually do the same, but be aware that the new Cylinders don't come like that (as they weren't standard that way).

 

Sorry for the long winded post, but I'd like to arm you with the best possible info - we are talking Brakes after all.

 

<Edit: Just one other point, some of the lines, while they may have Metric Threads actually take Imperial Spanners ie, M10 x 1.0 fitting, but a 7/16" Spanner is the correct one to use. I thought I'd mention that because you may assume that it has the 3/8" UNF Threads from the Imperial Spanner bit. I am convinced they did some of these things to drive us totally mad. >

Not long-winded at all. Cheers for a comprehensive reply & I just love the wheel nut check! It's approaching that time of year with you....so a very happy new year to you. still 15 hours to go here in Belgium. Cheers!

[Spider]

Only 4 hrs and 6 minutes here, but I'm not counting!

[Ethel]

Re the damaged rear pipe. It shouldn't have a tee at the rear if it's diagonal split.

[b_sdaddy]

So then, the saga continues into 2016.

 

MokeSpiders assistance (and others), has led me to this point. I'm going to establish if either (GMC167) 10mm or (GMC168) 3/8" and will buy the offending lines to the rear of which two are required:

 

This link shows the complete set from MS -

 

http://www.minispare...sic/GL4999.aspx

 

At around £100 it's comprehensive, and will address any further issues that crop up (as they do), when fitting.

 

Watching the pennies as always, can I just buy the two brake lines (F to R) and save some cash.? IF so, then could someone post a link or give me the codes (both metric & imperial)

 

 

cheers & a happy new year to you all.

[Spider]

Somerfords!

 

http://www.somerford...roducts_id=3958

 

http://www.somerford...roducts_id=3960

 

They only have them in Metric as theoretically, that's what your MC should be.

 

As a side note, for 100 quid, you could buy reasonable tools, the pipe and fittings and make them yourself and I think you'd even have change,,,,,,

[b_sdaddy]

cheers for the info.

 

Here's a link from ebay:

 

http://www.ebay.co.u...=STRK:MEBIDX:IT

 

The only problem is that it's copper, and not copper nickel.

 

The cars 40 years old and it's still on it's original braking system!!

 

 

For a car that does about 3000km/year, would I get a unanimous 'yes' to going with copper/nickel, or is it still open to debate? Considering its a bulk-standard 998 on drums, surely copper would be ok.?

 

Can still buy this kit and also a long length of copper/nickel, but loathed to do so, unless it's going to be dangerous to drive..

 

 

cheers as always

[Spider]

It's not a bad price for a whole kit, fittings, tubing, and tooling!   I will say though that the tool at the heart of it - the flaring tool - those particular ones aren't much good, though the can fairly easily be modified in to a good tool. The problem with those is the jaws that grip the tube need to come together dead flat, on the same plain, which they may when you do them up, however once you start flaring, they slip and so the flare doesn't come out square and they leak.

 

How do I know?  I have a similar tool, and yes, I modified it and now does perfect flares every time, though I do have a few tools for doing them, but that one is really good when working next to a bend. The modification involves the fitting of some dowels or pegs to that the jaws locate exactly to each other and can't slip, you can see them here;-

 

 

 

This is also a good tool, but tool only for around the same money    http://www.carbuilde...ipe-flaring-kit

 

Copper Piping - In some countries (like here) it's not legal, the supposed argument being that it work hardens and cracks, it may, but it will take a very long time and lots of miles. I have fitted it many moons ago as that was what was supplied to me from a Brake Shop (when it was legal), though legal or not, I wouldn't fit it these days, I get rolls of plated bundy tube and I feel among other factors, it does a nicer job.

 

Cooper was used, sometimes as OEM (not on these cars though!), for a very long time. I don't see a technical reason for not using it in your circumstances, but I would make regular checks of it. If - and I do mean IF - it's going to crack, it won't be mid-span in a length, but next to a fitting or a clip, that's where you should check.

 

I would also suggest looking in to your local laws too as it may have an Insurance Impact.

Edited by Moke Spider, 10 January 2016 - 08:32 AM.

[b_sdaddy]

So then,

 

just been to the garage, and with the master cylinder off, tried with one of the wheel nuts;

 

Anyway, tried getting the wheel nut onto the end on the male brake pipe coupling, as suggested, and it went no more than a quarter turn and then no more.

 

So with this, I'm thinking the brake pipe coupling is 10mm, so the master cylinder is therefore, also metric..

 

That'll be the GMC167 then!!

[jaydee]

From memory all the brake pipes from Minispares are cupro-nickel, you can always ask Simon what material they sell.

With 40 years old brakes, the most you replace the better, dont be afraid to open a can of worm, its your safety.