Brake Unions

[geoberni]

I realise Brakes is one of the most easily modified aspect of a Minor, with later 1000 slave cylinders to replace the early MM/S11 etc, but I have trouble getting my head around what fittings are used where.

I've been changing Basils Wheel Cylinders and Flexi Hoses today and found some really unmoveable unions. Whoever last assembled the brakes didn't do it well. Some of the unions, such as the little link pipes on the front cylinders, and the Connections on the inner wing to the Flexi have been too tight a bend, resulting in the pipe being jammed in and getting twisting damaged on loosening the union.
I know there are a mix of UNF and BSF on the car, but which is where??

CWs site kindly tells me there are 12 BSF & 4 UNF required, but not where each of them are
From the illustrations on ESMs site, they look indistinguishable from each other...

brake Unon.JPG (20.54 KiB) Viewed 2535 times

Where are the 4 UNF unions used?


I know some of you guys will know all this off by heart.....

[philthehill]

I think you will find that the UNF unions are relative to the front wheel cylinders.

[taupe]

Yes the front brake link pipes have UNF unions

Taupe

[geoberni]

Thanks for that guys. Makes sense when you sit and work out what connects where.
Today I'm doing the rear cylinders.
Not obvious in the manual that the half shafts need to be withdrawn and then there is just enough room to get the cylinder out....
So I'll be drawing up a shopping list of unions and will need to add oil seals for the shafts.
The rear flexi looked like it had a slight weep, yet was grollied up tight. Turns out there was no Copper Washer under it.

The person who fitted the brakes was over generous with the lengths of pipe so re terminating to replace a couple of mangled unions will not be a problem.
Just look how much excess is there.....
You'll note the pipes are held in place with cable ties. What are the 'genuine' retainers made of, as available at ESM? they look like they might be thin Aluminium, like the old 1950s/60s electric cable retainers before hammer in plastic clips we available.

20210613_115430.jpg (656.93 KiB) Viewed 2475 times

13/6/21-17:51 Edited to correct a typo, just because I could....

[philthehill]

The original brake pipe retaining clips were soft alloy similar to the electric cable clips you describe. Cable ties are a much better option as they do not rot away.
The union is normally mounted on the diff nose web and not on an additional bracket as per the photo.
The extra length will be of no matter as it will help with the pipe movement at the cylinder end of the pipe. The brake pipe needs to move with the brake wheel cylinder so you should not fit a clip close to the wheel cylinder.

[Mark Wilson]

This was one of my rare moments of trying to be as authentic as possible

DSCF9507.JPG (41.54 KiB) Viewed 2468 times

The brass cable ties came from this company:

https://www.carrotcycles.co.uk/control- ... -of-4.html

[geoberni]

The original brake pipe retaining clips were soft alloy similar to the electric cable clips you describe. Cable ties are a much better option as they do not rot away.
The union is normally mounted on the diff nose web and not on an additional bracket as per the photo.
The extra length will be of no matter as it will help with the pipe movement at the cylinder end of the pipe. The brake pipe needs to move with the brake wheel cylinder so you should not fit a clip close to the wheel cylinder.

Thanks for that info Phil,
I hadn't realised the Union wasn't in the right place. The only 'official' info, as such, that I could find, was in AKD3541, which doesn't go to that degree of detail, being the parts catalogue.
If the 'extra length' was going to be of any practical value regarding the movement of the rear cylinder, it would need to be at that end, and certainly not held down with several cable ties...

Union on Axle.JPG (81.39 KiB) Viewed 2463 times

This was one of my rare moments of trying to be as authentic as possible
The brass cable ties came from this company:
https://www.carrotcycles.co.uk/control- ... -of-4.html

They look nicer than the ones at ESM, and around half the price.
https://www.morrisminorspares.com/image ... 8_zoom.jpg

[jaekl]

The bracket is quite common.

[ManyMinors]

The bracket was standard on the Minor for many years and features in the parts book It was not fitted to later models and the union was mounted directly to the differential casing.

[myoldjalopy]

"Not obvious in the manual that the half shafts need to be withdrawn and then there is just enough room to get the cylinder out...."
But they don't need to be withdrawn! It can be a tight squeeze, but I replaced my rear cylinders recently and certainly did not have to remove the half shafts.

[geoberni]

"Not obvious in the manual that the half shafts need to be withdrawn and then there is just enough room to get the cylinder out...."
But they don't need to be withdrawn! It can be a tight squeeze, but I replaced my rear cylinders recently and certainly did not have to remove the half shafts.

I had to ease them out about an inch to clear the rim of the half shaft, the first one I did, the Driver's side the shaft was so loose it pulled out beyond the splines before I knew what I was doing. Shear panic for a moment until I worked out how to get it back in
Once the full disc of the shaft was out the way, I still needed a claw hammer to lever the cylinder past the bearing housing.
But the replacements fitted easily past the bearing housing.
The ones I took out presumably date from the rebuild in 1999. The rear ones didn't have any obvious markings, only the front had 'AP' cast on them.
The passenger side I simply withdrew about an inch and that was quite stiff on the 4 studs, needing gentle encouragement back in with a hammer afterwards.

20210613_125443.jpg (779.57 KiB) Viewed 2385 times

Trust me, it wasn't going to come past that Shaft Disc without risking some damage to the back plate. There was no more sideways movement, it was more than a 'Tight Squeeze'. The new ones are a couple of mm narrower and now slide up and down easily, whereas the ones I took out were pretty tight fit.
I would think the new ones would easily fit past the half shaft discs.

[myoldjalopy]

Well then, from what you say I would guess that the cylinders you had to remove were copies of the original design - and not good copies.

[jaekl]

I've always had to part the half shaft to get the cylinder out for the past 45 plus years. It may be because the outer piston isn't fully home.

[jaekl]

Could it be the smaller bore rear cylinders of the eight inch front brake cars are smaller diameter than the seven inch models? I've only worked on Series III Minors.

[geoberni]

Well it's taken me a few weekends, fitted in around other 'stuff' (including loosing a weekend as a delivery from ESM got lost in the post - but all credit to them, they quickly sent a replacement order), but having replaced the cylinders and some lengths of piping, I was putting the front shoes on when I noticed this...

20210702_175630.jpg (844.41 KiB) Viewed 2263 times

I checked the ones for the other side and realised that I have only 1 of the 4 front adjustors the correct size for 8" brakes, the other 3 are the original 7" brake ones
Yet another little example of bodgery during the restoration in 1999. How they managed to fit the brakes from the latter donor car, yet then use 3 of the 4 original adjustors, without realising the difference is beyond my comprehension....

Now as I understand it, the rear adjuster remained the same, since still 7", so I only need to get 3 replacements, is that correct?

Has anyone got any good tips on bleeding a system after changing all the slave cylinders?
I've got fluid through to every bleed nipple, but there's still clearly a lot of air trapped in there somewhere.

[geoberni]

I've always had to part the half shaft to get the cylinder out for the past 45 plus years. It may be because the outer piston isn't fully home.

Possibly, they were pretty seized up.

[myoldjalopy]

The manual does say to "withdraw the lower half of the piston from the wheel cylinder" before removing the rear cylinders from the brake-plate......I didn't need to even do that to remove them, although one was rather reluctant to come out!

[geoberni]

The manual does say to "withdraw the lower half of the piston from the wheel cylinder" before removing the rear cylinders from the brake-plate......I didn't need to even do that to remove them, although one was rather reluctant to come out!

I did note that, which didn't really help when the cylinder is seized solid.....
Given that is also the instructions for removing a cylinder from the early axle, when there is nothing in the way, it doesn't seem relevant to the obstruction aspect.

But all that aside, re my other post this morning, am I right in thinking only the front adjustors changed size?

[philthehill]

When the front brakes went from 7" dia to 8" dia the adjusters were beefed up. As far as I know the 7" rear brake adjusters remained the same.
https://www.morrisminorspares.com/brake ... es-p829507

https://www.morrisminorspares.com/brake ... es-p829450

[geoberni]

Thanks Phil
I thought as much, it's just not made clear by some of the retailers and even the AKD3541 showed a change to the Adjuster part number, but NOT the Mask, so that made me think it was essentially the same one.

I have no idea how to decipher the Change Point details on the far RH column.

3541.JPG (30.88 KiB) Viewed 2156 times

As the usual suspects all seemed to be out of stock, I took a look on ebay and found someone with a few available, so 3 sets of Mask/Adjusters ordered.