Morris Minor Owners Club

I am going to try to repair two Lockheed front cylinders. I will try to clean up the bores and pistons with fine wire wool and methylated spirit.
Does this sound reasonable?
Also, I will need to anneal the copper washer on the flexible hose. How much heat is needed, and how do you know when it is done?

Thanks, John.

Heat the copper washers until cherry red then quench in water, it's the heating up that softens the metal. If the bores show no sign of scoring, rust pitting or ridges after you clean them up then the cylinders should be OK to reuse.

panky wrote: ↑Sat Nov 15, 2025 10:02 am Heat the copper washers until cherry red then quench in water, it's the heating up that softens the metal. If the bores show no sign of scoring, rust pitting or ridges after you clean them up then the cylinders should be OK to reuse.

Thanks panky.

You won't like me saying this. No you can't attack the pistons and bores with wire wool. Read the workshop manual. it was written a long time ago but is most emphatic about the brakes. I'm sorry the cylinders are quite expensive but please just replace them.

Stephen

Sorry to disagree Stephen but if no pits or scores gentle cleaning of surface rust is acceptable. Ensure thoroughly cleaned with brake cleaner before assembly. Only use genuine seal kits not copies. Before fitting shoes clamp cylinder(s) with a G clamp apply full brake pressure for a while(pedal can be held applied with block of wood) and check for leaks.
Any repair on a brake system is the responsibility of the repairer.
I am coming at it with 55year of experience and have repaired many wheel an master cylinders as repair kits were common place before high labour cost and cheap copies.
If you are not 100% confident in your repair then replacement is your safer option.
The minor has a single circuit brake system so a leak can result in no brakes

I took the drums off today to have a closer look at the cylinders.
I think that what I thought was weeping might just have been condensation, bearing in mind that the pistons are 'upside down'. The car is kept outside.
I pulled the pistons out a bit, and there was no brake fluid resting in the metal caps.
I put the drums back on, wedged a piece of wood against the seat and brake pedal and went and had my elevenses..
About half an hour later I took the drums off again, and nothing had changed.
So I think I am going to leave well alone.
But will keep an eye on the level in the MC.

I think I was spooked by having so many non-Lockheed cylinders failing in the past.

Thanks folks.

Bill_qaz wrote: ↑Sat Nov 15, 2025 12:14 pm Sorry to disagree Stephen but if no pits or scores gentle cleaning of surface rust is acceptable. Ensure thoroughly cleaned with brake cleaner before assembly. Only use genuine seal kits not copies. Before fitting shoes clamp cylinder(s) with a G clamp apply full brake pressure for a while(pedal can be held applied with block of wood) and check for leaks.
Any repair on a brake system is the responsibility of the repairer.
I am coming at it with 55year of experience and have repaired many wheel an master cylinders as repair kits were common place before high labour cost and cheap copies.
If you are not 100% confident in your repair then replacement is your safer option.
The minor has a single circuit brake system so a leak can result in no brakes

Wouldn't it be better to fit fresh pattern seals from ESM, rather than new old stock ones from Lockheed?

stuffedpike20 wrote: ↑Sat Nov 15, 2025 12:49 pm

Bill_qaz wrote: ↑Sat Nov 15, 2025 12:14 pm Sorry to disagree Stephen but if no pits or scores gentle cleaning of surface rust is acceptable. Ensure thoroughly cleaned with brake cleaner before assembly. Only use genuine seal kits not copies. Before fitting shoes clamp cylinder(s) with a G clamp apply full brake pressure for a while(pedal can be held applied with block of wood) and check for leaks.
Any repair on a brake system is the responsibility of the repairer.
I am coming at it with 55year of experience and have repaired many wheel an master cylinders as repair kits were common place before high labour cost and cheap copies.
If you are not 100% confident in your repair then replacement is your safer option.
The minor has a single circuit brake system so a leak can result in no brakes

Wouldn't it be better to fit fresh pattern seals from ESM, rather than new old stock ones from Lockheed?

Depends on how the OE have been stored, try to get sealed packaging if poss, it also depends where the pattern parts come from. At the end of the day its your car your choice, nobody can tell you what to do, only advise from individual experiences, which will vary person to person.
Sounds like you got leak free anyway, so good luck with your rebuild.

Bill_qaz wrote: ↑Sat Nov 15, 2025 12:14 pm Sorry to disagree Stephen but if no pits or scores gentle cleaning of surface rust is acceptable. Ensure thoroughly cleaned with brake cleaner before assembly. Only use genuine seal kits not copies. Before fitting shoes clamp cylinder(s) with a G clamp apply full brake pressure for a while(pedal can be held applied with block of wood) and check for leaks.
Any repair on a brake system is the responsibility of the repairer.
I am coming at it with 55year of experience and have repaired many wheel an master cylinders as repair kits were common place before high labour cost and cheap copies.
If you are not 100% confident in your repair then replacement is your safer option.
The minor has a single circuit brake system so a leak can result in no brakes

THIS^^^

Steel wool does come in different grades, BTW. Common sense needs to prevail. I would hone them.

Honing the cylinders is the only acceptable way to get the seal surface back to a new/useable condition.
Any other way and the likely hood of generating hollows in the cylinder surface is increased.
This is the make and type of hone hone I use:
https://www.ebay.co.uk/itm/136737496854 ... R_KF3YTRZg

I know that in order to keep the cylinders in good condition, I should click the adjusters back a couple of clicks so that the pistons have to move a bit; but having a longer brake pedal does not seem right.

philthehill wrote: ↑Sat Nov 15, 2025 4:07 pm Honing the cylinders is the only acceptable way to get the seal surface back to a new/useable condition.
Any other way and the likely hood of generating hollows in the cylinder surface is increased.
This is the make and type of hone hone I use:
https://www.ebay.co.uk/itm/136737496854 ... R_KF3YTRZg

Nice tool Phil, used one in past and much larger Delapina for truck engine cylinders, affectionately known as the "nodding donkey"
I did say manual cleaning of light surface rust but obviously honing is way better. If you have one and more importantly know how to use it, stone grade lube speed etc. Internal micrometer is also a great accompaniment

Bill
That is a nice machine too.
As you will know the rotational speed and the up and down movement in the bore being honed is most important so you end up with a good cross hatch. Also a lubricant is required. I have used a light oil i.e. 3 in 1and WD 40 at various times dependent upon the job in hand.
Phil