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Re: Hydraulic brake pipework

I forgot to mention in my last post that the grub screws need a suitably-sized ball bearing to cover the drilled hole.

I did not buy these, I had some spare in the garage. The grub screw has a convenient depression to locate the ball bearing, which is great!

Gary

Location: Saltdean, Brighton - sunny today!

Re: Hydraulic brake pipework

Just to bring matters up-to-date following my last post - nearly three weeks ago - it has taken that time to get an acceptable solution!

In the last post, I mentioned that I was not happy with the banjo bolt, which I had high hopes, but not any more.

The reason for the disatisfaction were two-fold.

Firstly, with the brass banjo adapter (which I really wanted to use), the length of available thread to screw into the wheel cylinder was only about 3-4mm, whilst the banjo would screw in, I was concerned over the security of the fixing particularly due to stripping the threads when fully tightened in position.

Secondly, the female thread was not UNF and I tried to find out from the supplier what it was, but they never bothered to reply, but speaking to another specialist, it could be NPT, which would not be any good for our purposes!

So, that meant that this banjo bolt was not going to be any good, which was a shame as if it had worked it would be been a neat solution.

Then, as an alternative (I had given up by now in trying to find a fully male/female UNF banjo bolt, these seem to be impossible to find now) I considered a banjo bleed bolt.

Instead of having the 3/8" UNF female connection, there is a bleed nipple (1/4" I think), which would make for a neat solution.

Furthermore, using a single port for two connections could give rise to air becoming trapped in the wheel cylinder due to its inverted orientation, so having the bleeding operation at this point may help purge air from the system, but as I have not got that far as yet with the plumbing so, too soon to say!

The manufacturer, Goodridge, had listed a product that should have been perfect, a banjo bleed bolt that had a 25mm dimension between the hex and the end of the thread - necessary to allow the brass banjo adpater to be used with sufficient thread to get a secure fixing.

Unfortunately, Goodridge no longer manufacture this item and their standard banjo bleed bolt has a 20mm dimension between the hex and the thread end and with this screwed in place, the problem is the same as the first banjo bolt that I had with an insufficient thread for a secure fixing!

Oh dear, I tried to source alternatives, but there was no old stock or anything else suitable that I could find and I really did not want to use a double bolt, which would have worked ok, but I felt that this looked a bit on the messy side and a bit DIY.

I had considered having the brass union machined to reduce the thickness at the business end by 2-3 mm, there is sufficient scope to do so, but I am unwilling to undertake such an alteration without the manufacturer's consent just in case there is a compromise on safety and I do not have the necessary expertise to determine this, so that was out of the question.

So, after much consideration, chatting to Goodridge themselves, who were trying to be helpful, but could not suggest a solution other then to refer me to their largest distributor of their products, CAM Auto.

I contacted CAM and they were very helpful (interestingly, they suggested machining the brass banjo adapter!) but when I gave a negative response they proposed an alternative.

In the absence of sourcing a suitable banjo bolt, I have decided to change tact and go with their proposal, which meant changing the banjo adapter and ditching the brass item that I already have.

The parts came today and I trial-fitted these and I have to say that the result will be acceptable and will work very satisfactorily even if the parts look a bit too modern, but if I cannot get the bit I want there really is not much choice. Anyhow, once fitted, they will be out of sight, so long as they perform, then that is ok with me!

So, I now have an UNF banjo bleed bolt (standard length) with a banjo 70-degree adapter with a 3/8" UNF (JIC), to make a female connection to the bridge pipe with brass union (obviously, the pipe flare will be JIC to match). The bolt & adapter are in stainless steel, which are very good quality and are nice to use.

Here are the pictures: -

NSF

Showing the NSF, at the trial-fitting, good clearance.

Goodridge SS2

Here are the parts.

Goodridge SS1

Here they are all together.

So a change to what I had originally proposed and I am still keeping an half-eye for a 25mm long banjo bleed bolt so I can use the brass banjo adapter, but not important!

I thoroughly recommend CAM Autos, very helpful, interested in the project and keen!

If anyone is interested in copying what I am doing, here is my updated parts list:-

1. UNF grub screw and ball bearing - see previous post

2. Banjo bleed bolt (cw bleed nipple) 775-03BNC, cost £18.28 plus VAT each (this is for stainless steel, zinc-plated steel is MUCH cheaper), Banjo 70-degree adapter SBK570-03C, cost £7.13 plus VAT each, again, stainless steel.

These are both manufactured by Goodridge and I think these actually made in the UK factory!

Supplier is CAM Auto Developments, Web: www.camauto.com, Tel: 01727 827717, E-mail: sales@camauto.com.

You can order on-line, but it is cheaper to speak to them as they discount the on-line prices!

The stuff is available from other suppliers, so better prices might be possible, or fit a cheaper material, although I think the banjo adapters only come in stainless steel, not sure on that though!

I will post photos when I have plumbed the new parts in so you can see how it looks, after starting to feel despondent with all the dead-ends, I am now quite excited!

Thanks.

Gary

Location: Saltdean, Brighton

Re: Hydraulic brake pipework

And now for the handbrake-
I have a special I converted many years ago and use an external handbrake with cable pulling a rod one side and the cylinder arm on the other. It was quick and easy to fit but I cant remeber what the cable came from.
On my new car, a Pearl, I want to retain the original brake so intend to use one side cable to the rear cylinder arms.
I wondered if you have sorted this out for your car yet ?
I managed to find banjos for the front brake rear cylinder , although I had to machine slightly to fit.

Re: Hydraulic brake pipework

Charles, I have not got around to the handbrake as yet, although I have Morris Minor cables to attach to the original handbrake lever, I am going to remove the brake cross-shaft as this will not be needed and just connect onto the lever itself.

I did not see the point in retaining the original cables as their operation (for rear brake cylinders that are Morris Minor) is in the wrong direction to pull the wheel cylinder levers, and to use them would entail re-routing when it can be simpler to use a direct line ulitising the bowden principle of cable operation.

Haven't got there yet, but I am hoping that this will be a much easier exercise than the arrangement for the front brakes!

I was interested to read that you had your brass banjo machined, have you got pictures of this? How much metal did you have removed?

Gary

Location: Saltdean, Brighton

Re: Hydraulic brake pipework

Gary, here`s my solution for the hand brake on the special.The crosshaft is one I made up, as my lever is on the outside of the car.One end of the morris minor cable,outer sleve is attached to a bracket on the axle tube the othere is fastened to the rear cross member There`s four photo`s%%bbCodeItem_1%%

cheers Ian

Location: Worksop Notts

Re: Hydraulic brake pipework

Gary

I think I have e-mailed a photo to you.
My banjo was the unf type and the bolt had the bleed nipple included. I had to turn the banjo depth down and machine under the hexagonal head of the bolt to increase its depth to fit as it was not intended for this banjo originally.
All of this was far easier on the special with dropped radius arms!


For the handbrake I intend to use one (longer inner and outer type) side cable in the original postion , to a yolk and rod along the length of the back axle. I have a similar arrangement on my special with a simple bearing for the rod on the diff case.

The hydraulic master cylinder I have , is to be mounted close to the brake light switch on the chassis cross member. At this low level I will be using a remote reservoir- possibly hidden in the battery box.

Charlie

Re: Hydraulic brake pipework

Thanks Charles,

For the benefit of the others, I have uploaded your photos (I use photobucket to get these on here), which I hope you don't mind, I like the look of what you've done, nice and neat!

The brass banjo adapter that you have only seem to be available now with a UNC thread, which is not a problem, all that has be remembered is which way the unions go!

Photobucket



Photobucket

Location: Saltdean, Brighton

Re: Hydraulic brake pipework

Hi I have Hyraulic twin leading shoe brakes on my A7 special. Most of the brake system is Morris 1000, BUT the back plates are alloy. I have seized pistons in the Twin leading shoe front brakes and think thes pistons are NOT Morris. I do not know what they are. Does anyone have a similat set up. The brake cylinders are alloy all round.

Re: Hydraulic brake pipework

There are 2 styles of Morris cylinder. The early 7 inch brakes from 1948 to 1953 use alloy bodies and the later ones are steel. New early ones are about £35 and the later ones as low as maybe £7 each.

If you can get a photo up they can be identified. I have both types here if you need any help and can let you know where to get the early ones.

Location: 10 miles west of Cardiff

Re: Hydraulic brake pipework

Gary

Twin leading shoe is possible if you grind the lower port area of the rear front wheel cylinder and fit a blanking plug.
You then have to fit a banjo to the top port on the rear cyclinder to enable a bleed screw and a pipe fitting at the same port.
I have picture of mine on my Pearl if you e-mail me.
My master cylinder on my Pearl is under the drivers footwell floor with a remote resorvoir under the drivers seat.

I converted special during building but used a reliant robin pedal box with twin master cylinders.

Location: southampton

Re: Hydraulic brake pipework

No bad thing to re-invigorate this thread.
I've just been head-scratching to work out the leading vs trailing issue,and comparing the backplates on all the pictures.

Am I right in thinking that the best way for simple ID of the relative position of the backs of the cylinders in the backplate, viewed from the rad:

trailing set up = lower at the front

leading set up = higher at the front

Or not?

Re: Hydraulic brake pipework

For leading shoe operation when the car is driving forwards, the piston pushing the shoe is in the direction of rotation the drum and it is the self-servo effect of the drum rotation that "pulls" the shoe harder than would be the case with a trailing shoe, so pedal effort is more effective for the same pressure and to answer your question, if the back plate layout is following a "standard" pattern, then as you say, leading set-up is slightly higher at the front than at the rear, with the piston at the front pointing downwards & at the rear, the piston is pointing upwards so that the operation is in the direction of the forward motion.

Of course, when the car is in reverse, the front brakes are twin trailing and much less effective and more pedal pressure is required to apply the brakes.

Location: Saltdean, Brighton

Re: Hydraulic brake pipework

Mike Inglis
My take on twin leading front hydraulics on my racer, made easy with dropped steering arms and lowered radius arms.


A view of the so-called "dropped steering arms and lowered radius arms" would be much welcomed please Mike.
Thanks,
Renaud

Location: Brittany

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