Front Brake Banjo Bolt problem

[gtt1951]

Hello Folks, and a Happy Easter to you all.
I've been spending my time doubled over under the front wheel arch of my Low-light, trying to remove one of the brake cylinders.

IMG20250420115839.jpg (1.07 MiB) Viewed 7377 times

The Banjo Bolt's hex head takes a 5/16" Whitworth spanner (nice tight fit) but I cannot get a good purchase on the open-ended spanner shaft and, when trying to undo it, it slips off and is in danger of rounding off the head.

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I've Googled spanner sizes and the new Google AI search comes out with the fact that a 3/8" BSF bolt requires a 13mm spanner - total rubbish.
The ESM parts site, has the bolt but doesn’t mention the spanner required for removal.
I don't have a 5/16" W ring spanner and my 5/16" socket does not get a good fit (due to access restrictions).

Am I using the correct spanner size?

Should I try a bit of heat on the bolt head?

I have searched the forum and cannot find an answer to the early Series MM original brake cylinder banjo bolt question.
Any help would be greatly appreciated.

Regards

George.

[philthehill]

Try some heat on the bolt head and get yourself some Whitworth spanners both ring and open-ended.
The spanners do not have to be new as there are plenty of good S/H spanners on 'e' bay. Gordon or Britool are a good choice. Deep offsets are very handy.

[svenedin]

I recently had to remove some very corroded machine screws from ancient brake backplates. Liberal dousing with PlusGas and Whitworth sockets did the trick. It is better to buy the correct tool than try to clear up the mess from using the wrong tool.

Stephen

[gtt1951]

Thank you Phil and Stephen for responding,
I do have American and Sheffield made open-ended spanners in both Whitworth and AF sizes (bought at a Beaulieu Autojumble), also the remains of my BriTool ring-spanners (the bulk of my BriTool tool roll was stolen years ago) but I don't have the 5/16" W one, also sockets in Whitworth, SAE, and Metric, plus a number of odds and sods.
The open-ended 5/16" W spanners that I tried are USA made by VLCHECK, and they are old "refurbished" ones

VLCHEK spanners.jpg (1.29 MiB) Viewed 7301 times

My problems are of access - I can't see the bolt head unless I use a mirror - one hand holding an old dressing table mirror, the left (weaker hand) trying to fit the spanner. Since my right knee was replaced, I'm not supposed to kneel on it, so working under a wheel arch presents me with problems and I have now bought a Garage Creeper that converts into a wheeled stool (as seen in the next pic of me jacking up a rear wheel on my Traveller - the red spare Traveller seat back is used to throw myself down on one side to be able to place jack and axle stand underneath the car).

Kit required to jack up car.jpg (946.26 KiB) Viewed 7301 times

Hand mirror.jpg (1.48 MiB) Viewed 7301 times

My main question was about the size of the spanner - is 5/16"W the correct one to use?

An alternative thing I could try (thought of this during the night), as I can't apply enough downward pressure to any socket or spanner, is to remove the complete backplate and then hold it in a vice by clamping the wheel cylinder that needs replacing, whilst I heat up the bolt head and try removing with a 5/16"W socket - the pipework does not go behind the king-pin

Backplate pipework.jpg (887.78 KiB) Viewed 7301 times

But the problem here would be that I'd have to undo the flexible pipe from both ends of its fitting as the end at the banjo is not a joint that would rotate independently of the pipe

I've tried to reduce the size of all the images that I have posted this time.

Best regards,

George.

[Bill_qaz]

Might seem a silly question but why not turn steering to full lock to give you better visibility/access to the banjo bolt?

[svenedin]

You need a socket on it. I have been in your position. A ring spanner is not worth having. There’s not enough room. Forget WD40. You need the proper stuff. Stephen

[gtt1951]

Might seem a silly question but why not turn steering to full lock to give you better visibility/access to the banjo bolt?

Bill,
I would need to jack up the offside front again to be able to turn the nearside hub leading edge outwards - I was trying to get this done without too much difficult (for me) messing about underneath the car.
I would still be unable to get my body weight behind the socket (to keep it on the bolt head) but, as you say, I would have a better sight picture.
I'm still uncertain as to whether a Whitworth 5/16" socket (or spanner) is the correct size - I've gone though all my spanners and a 9/16" AF ring spanner (and the equivalent open-ended spanner) looks, to my naked eye, the same as the 5/16" W socket/spanner but, alas, having just tried it, the ring is a fraction too small to go on.

G.

[gtt1951]

You need a socket on it. I have been in your position. A ring spanner is not worth having. There’s not enough room. Forget WD40. You need the proper stuff. Stephen

Stephen (see answer to Bill about ring spanners), before attempting to undo any of the backplate bolts, I had applied Plus Gas (A) to the parts (I always use this for freeing items and not WD40).
It has started raining now, so I'm back indoors.

Thanks,

George.

[svenedin]

I cannot say with absolute certainty but I’m pretty sure it is Whitworth. Regardless, what really matters is what fits given corrosion. Personally I might take the backplate off. It was so much easier that way…

[gtt1951]

Bill, Phil and Stephen,
Thank you all for your inputs and I've now made a decision (not easy for a Piscean).
The sun had popped out and I tried the backplate bolts and they have slackened off using a 1/4" BSW socket.
Strangely, these "new" sockets are stamped with WW rather than BSW (could be Chinese - bought at Beaulieu).

Backplate bolts.jpg (830.63 KiB) Viewed 7243 times

I'm going to undo the flexible brake pipe at this union

Brake pipe union.jpg (566.82 KiB) Viewed 7243 times

Which has now been sprayed with PlusGas - so waiting for it to do its work and I'll resume tomorrow with the better weather predictions.
I'm hoping that the solid pipe retainer comes out easily and without causing damage to the feed pipe (which looks a trifle kinked)

Thank you all (will update this post tomorrow),

George.

[svenedin]

Good luck but from your excellent photos not enough PlusGas. I don’t regard it as a fair fight until not only my clothes reek of diesel but the entire house.

[Bill_qaz]

WW = Whitworth
BSW = British Standard Whitworth
Both are the same
The same spanners are also usually marked BSF ( one size different)
British Standard Fine, the thread is finer but the the spanner fits both marked sizes.
AF spanners for UNF or UNC are marked in the size of the across the flats dimension of the nut or bolt head.
Metric spanners are also across the flat dimension but in millimetres.

[svenedin]

"Metric" spanners are some kind of Napoleonic invention. I don't own any or believe these "Euro" measurements actually exist. Next it will be negative earth!

Stephen

[Bill_qaz]

"Metric" spanners are some kind of Napoleonic invention. I don't own any or believe these "Euro" measurements actually exist. Next it will be negative earth!

Stephen

So how do you fix your German chariot
Stephen, your minor has more mods than a Brighton weekender, you will soon come over to the darkside of negative earth

[svenedin]

"Metric" spanners are some kind of Napoleonic invention. I don't own any or believe these "Euro" measurements actually exist. Next it will be negative earth!

Stephen

So how do you fix your German chariot
Stephen, your minor has more mods than a Brighton weekender, you will soon come over to the darkside of negative earth

I don’t touch the German chariot! All I do with that is fill it with petrol.

Haha. No I don’t understand the negative earth. Not likely

[gtt1951]

Quick update -
Backplate is off, the banjo bolt is out and the seized cylinder removed - some of this will have to become another topic "removing backplate with brake cylinders".

The problem banjo bolt.jpg (353.98 KiB) Viewed 6667 times

Metric - the Morris Side-Valve engines have, mainly metric thread bolts/screws - many are M8 Fine (so metric does exist and the Moggies have every type and size of bolt and use various spanners under the sun!).

My 1960's socket set (given to me in the early 1970's) contains Whitworth and SAE (Stamped Addressed Envelope ) sockets, but the Whitworth sockets are stamped "Whit" - so a 3rd variant.

The spanners and sockets used to do today's work were 11mm (brake pipe union), 1/4"W (bolts and nuts), 15/16"AF (brake line locking nut), 5/16"W and a pair of Mole Grips (both for the Banjo Bolt) - a real mix.

Stephen - the picture of the brake pipe joint was taken before the whole was doused in Plus Gas (need to buy more now)

Phew!

George.

[Bill_qaz]

George no metric on minors unless retrofit.
But certain sizes can coincide or very close.
Example 11mm, 7/16 AF, 3/16 whitworth .
You can google a cross reference list, something like this may help you.
https://www.baconsdozen.co.uk/tools/con ... charts.htm

[svenedin]

Well done. Glad to hear the offending bolt is out! I had to do a similar job recently and it was quite difficult but the backplates were not on the car. I think the brake cylinder bolts are particularly awkward due to dissimilar metals corrosion. Years ago I had to do the same with the backplate on the car and I ended up with a bolt that had started to round off. I think in the end I did a bodge by hammering on a socket that was slightly too small and that did work even if it is not good workshop practice. Sometimes you just have to work with what you have and a bit of make do and mend. I really dislike putting a lot of force on a bolt and it suddenly letting go which is what gave me Tennis Elbow and many grazed knuckles over the years. A tip is that sometimes counterintuitively, it helps to slightly tighten up a bolt before trying to undo it. PlusGas has always worked pretty well for me even if it does stink. There is a product from WD40 called "Specialist Penetrant" (this is not ordinary WD40) which I have also found works well.

Stephen

[gtt1951]

Getting the bolt out, yesterday, presented me with some problems as the access to the bolt-head was still impaired - just as well I followed Stephen's suggestion of removing the backplate from the stub axle.
With the assembly clamped in a large Record bench vice, with the vice jaws holding the offending cylinder, I started to attempt to remove the bolt.
The first problem was that all my 5/16"W open-ended spanners couldn't get a good purchase on the bolt head as it had been a bit mangled in the past.

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The circled area is where there isn't enough room to mount the socket

Socket prob-2.jpg (438.44 KiB) Viewed 4775 times

You can just see that the socket does not fit flush, so cannot get a good grip on the bolt head.
So, what to do? - I know, locate a pair of Mole Grips and try those.

After a bit of fiddling to get the correct pressure when the grips are locked (and not to cause further head damage) together with applying liberal heat from a "blow torch" - it worked!

Banjo bolt out.jpg (1007.14 KiB) Viewed 4775 times

Next, the cylinder had to be removed, using an American made 1/4"W open-ended spanner

Cylinder securing nuts.jpg (1.69 MiB) Viewed 4775 times

Then, with a couple of taps with a hammer, the cylinder came out.

A couple of taps with a hammer and the cylinder is out.jpg (428.8 KiB) Viewed 4775 times

Not sure why all the tacky mess on the cylinder is there!
Looking at the state of the bolt I had to take a decision to order replacements from ESM (decided on 4 bolts, in case of future problems).

The bolts arrived this morning - next day delivery, good old ESM!

As the weather had turned overnight, there was no point in trying to work on the car today to reconnect everything (using a refurbished wheel cylinder obtained from Bryan Gostling).

George.

[svenedin]

Where there’s a will there’s a way. Great stuff. A very handy tool is a Dremel with a tapered conical grinding stone and cut off discs. For recent work on the rear hubs I found that the hub nuts had been so butchered by the use of a chisel that the proper spanner would not fit. I had to grind the digs out of the nuts before the spanner would fit. The cut off discs are handy if there's no option but to cut the nut/bolt. I would be scared to use a full sized angle grinder. They are too powerful and in my hands too likely to cause collateral damage.

Stephen