Hydraulic brake conversion backplate

[Dennis Nicholas]

Viteran

I am just reassembling my rear hydraulics.  The back plates are the Morris Minor ones with the centres built out so back plate is further back to align shoes with drums. They have the BEEHIVE springs that hook onto a bracket on the back plate to hold the shoes in place against the back plate.  On the MM the  springs that pull the shoes together should fit between shoes and back plate so they ALSO pull the shoes towards the back plate, but as shown in your photo the built out back plate centre leaves no room to put them in the correct place so they have to be, as yours, on the outside of the shoes. The springs are tending to pull the shoes away from the backplates (in-spite of the BEEHIVE springs) so that the shoe friction surfaces are not parallel with the drum surface........not good.  How do you get the shoes to stay in and parallel? the shoes should, I believe, slide on the raised faces on the backplate just outer of the BEEHIVE fixing bracket  (in this position the friction surfaces are parallel with the drum).  I see you have the slightly different version (earlier back plate?) which has the BEEHIVE spring held to the back plate with split pins.
I have seen somewhere that someone drilled the back plate to take an M5/M6 or 2BA bolt which went through the shoe and back plate and with a lock nut outside the backplate adjusted the bolt till it just held the shoe nearly against the back plate (large washer under head to cover hole/slot in shoe).  I think the hole for the BEEHIVE spring would be big enough to allow shoe to move in and out without touching bolt and with lubricatio the washer under the bolt head would allow shoe to slide easily against the washer.
I am going to look at whether I can fix with the bolt method and whether the BEEHIVE spring can remain or if they will have to be removed and just have the bolts.

Does anyone else have this non parallel problem......how have you overcome it?   or   has anyone managed to have the springs in their correct place between shoe and backplate?  Perhaps some conversions were better engineered so that the middle built out section was made that bit narrower and the springs fitted where they should be??  There is not much distance in being able to get the springs inside (though they would probably just touch) and them not going in at all but sitting on the surface of the centre built out plate-to-axle mounting flange.

Dennis

[Charles P]

Viteran

I am just reassembling my rear hydraulics.  The back plates are the Morris Minor ones with the centres built out so back plate is further back to align shoes with drums. They have the BEEHIVE springs that hook onto a bracket on the back plate to hold the shoes in place against the back plate.  On the MM the  springs that pull the shoes together should fit between shoes and back plate so they ALSO pull the shoes towards the back plate, but as shown in your photo the built out back plate centre leaves no room to put them in the correct place so they have to be, as yours, on the outside of the shoes. The springs are tending to pull the shoes away from the backplates (in-spite of the BEEHIVE springs) so that the shoe friction surfaces are not parallel with the drum surface........not good.  How do you get the shoes to stay in and parallel? the shoes should, I believe, slide on the raised faces on the backplate just outer of the BEEHIVE fixing bracket  (in this position the friction surfaces are parallel with the drum).  I see you have the slightly different version (earlier back plate?) which has the BEEHIVE spring held to the back plate with split pins.
I have seen somewhere that someone drilled the back plate to take an M5/M6 or 2BA bolt which went through the shoe and back plate and with a lock nut outside the backplate adjusted the bolt till it just held the shoe nearly against the back plate (large washer under head to cover hole/slot in shoe).  I think the hole for the BEEHIVE spring would be big enough to allow shoe to move in and out without touching bolt and with lubricatio the washer under the bolt head would allow shoe to slide easily against the washer.
I am going to look at whether I can fix with the bolt method and whether the BEEHIVE spring can remain or if they will have to be removed and just have the bolts.

Does anyone else have this non parallel problem......how have you overcome it?   or   has anyone managed to have the springs in their correct place between shoe and backplate?  Perhaps some conversions were better engineered so that the middle built out section was made that bit narrower and the springs fitted where they should be??  There is not much distance in being able to get the springs inside (though they would probably just touch) and them not going in at all but sitting on the surface of the centre built out plate-to-axle mounting flange.

Dennis

I have the beehive springs held in with split pins.
I've found that compressing the spring as I fit the split pin ensures that the shoes don't suffer from the "pull away" that you describe 

Charles

[Tony Betts]

If anyone is interested in taking over manufacture of the aluminium backplates.

The patterns, and all the fitting parts I have. cylinders and spring etc. Are all up for sale.

Check our website, Tony.7ca@aol.co.uk

Thanks Tony.

[Dennis Nicholas]

merlinart

There are a number of owners who are now converting their cars back to cable brakes, so if you are patient you should find a set, and if you are lucky you may even find the parts to keep them working for a few years. Be aware though they will not give you any better braking, simply a different method of actuation.

Be aware that in UK all parts for hydraulic brakes are available from various Morris Minor suppliers (look at ESM Morris Minors for example)  and in view of the popularity and numbers of these cars supply should be guaranteed for long to come.......even back plates but they would need the modifying offset.

Dennis

[Terrytuned]

Brake shoe back plate retaining springs, I use Girling shoe retaining springs much better than the lockheed bee hive springs (see photos) If you want to use your existing bee hive springs cut out the centre leg retain with a 5mm screw and upside down 5mm flange nut.

[Dennis Nicholas]

Terrytuned

Thanks for that (I was typing my above when you posted)

Just wonder if the springs are needed at all or just bolts set to correct length.

How did you decide where to drill the hole in the back plate?   presumably you have this system fitted and working and the shoes will travel from fully in when new to their fully out when worn position without fowling the bolt.

Dennis

[Dennis Nicholas]

Terytuned
which Girling springs/pins/washers did you use and where could I get some?  
Have been looking around the web but no luck so far.

Pin and spring length is obviously important.
I have come across this type on other cars in the past and as you say found them to be reasonably easy to use.

[Viteran]

Hi Dennis
I had not noticed a problem with the shoes held by the beehive spring, but it has been a while since I used the car. You got me thinking and I looked up the arrangement in a manual from a marina I had 30+ years ago and there the tensioning springs alternated,one in front and one behind the shoes, wihen I go back I n the garage I will see about taking the drums off and I think there may be [on my setup anyway] Room for one spring behind the shoe and the othe in front which I imagine would stop the tendency for the shoes to flip outwards.
As I said it has been several years since the Austin has been active the problem I have now is that I suspect I need a new master cylinder or I have an airlock in the flexible brake hose that runs over the back axle, either way progress is slow. Will clamp the hose to see if that is the problem area or will buy a new master cylinder.
Ian

[Dennis Nicholas]

Hi Dennis
I had not noticed a problem with the shoes held by the beehive spring, but it has been a while since I used the car. You got me thinking and I looked up the arrangement in a manual from a marina I had 30+ years ago and there the tensioning springs alternated,one in front and one behind the shoes, wihen I go back I n the garage I will see about taking the drums off and I think there may be [on my setup anyway] Room for one spring behind the shoe and the othe in front which I imagine would stop the tendency for the shoes to flip outwards.
As I said it has been several years since the Austin has been active the problem I have now is that I suspect I need a new master cylinder or I have an airlock in the flexible brake hose that runs over the back axle, either way progress is slow. Will clamp the hose to see if that is the problem area or will buy a new master cylinder.
Ian

Thank you.
The Morris Ital also had strong larger spring by the pivot  inside shoe between shoe and backplate and the one by the cylinder (weaker I suspect) on the outside of the shoe. I think they were probably Girling)

I have not been able to work out which way the hook on the beehive spring should go onto its bracket....hooked on from bottom upwards or from top downwards.
Look forward to your investigation. Photos?

Just looked back through the thread at your February post with Photos.....looks the same as my items but my beehives are hooked to original internal bracket and not held by split pins as yours are.

Just awaiting now for reply from Terytuned ref Girling springs/pins/washer he uses. Which car originally from and a supplier.

Dennis

[Viteran]

Hi
The split pin method sounds a lot easier than trying to hook onto a bracket which sound like a s*d of a job Just push the pins through compress beehive onto shoe and bend back the pins!
Just been speaking to my son in Leicester who is a real engineer( not like me) and he had several suggestions that I should try next time I’m down t’ pit ( as they say in Yorkshire) under the Austin
Ian