Morris Minor Owners Club

Posted: **Mon Jul 25, 2022 10:27 am**

Also, it is not unusual for the hub seals to leak if you have had to hit the drum a lot to get it off, as the blows from the mallet can disturb the seal.

Posted: **Mon Jul 25, 2022 10:51 am**

Thanks guys. Now my breather is very clean I'll keep an eye on the situation (once the cylinders are replaced and I can actually drive it...).

(I'm quite excited to be using my torque wrench so any excuse to take the wheels off

)

Posted: **Mon Jul 25, 2022 11:21 am**

What torque needing nuts are you getting excited about ? ?
The wheel cylinders are not retained by nuts or bolts and there is no torque figure for the hub nut (just very tight).
The wheel nuts are the only nuts that you may need to torque tighten when replacing the wheel cylinders.

Posted: **Mon Jul 25, 2022 11:28 am**

philthehill wrote: ↑Mon Jul 25, 2022 11:21 am What torque needing nuts are you getting excited about ? ?
The wheel cylinders are not retained by nuts or bolts and there is no torque figure for the hub nut (just very tight).
The wheel nuts are the only nuts that you may need to torque tighten when replacing the wheel cylinders.

Just the wheel nuts. I gather it's not strictly necessary but it's fun all the same...

Posted: **Sat Aug 06, 2022 6:46 pm**

Hi guys!

So, an update on brake progress. I managed to change and bleed everything, however, I now have a different problem...

Now, on one side, when I press the brake pedal I don't get enough resistance at the drum I can still turn it by hand. I can feel that the brakes have been applied a bit not as much as on the other side which is impossible to turn.

Does this sound like just a duff cylinder, and it's my bad luck that I managed to get a rubbish one or have made a stupid error during the installation?

I believe I've adjusted the adjusters properly by clicking them all the way out until the drum is impossible to turn and then clicking them one back.

Thank you in advance, I appreciate everyone's help and apologies for my mechanical ignorance

Posted: **Sat Aug 06, 2022 11:22 pm**

It does seem that the cylinders on one side aren't working properly. Have you tried taking the drum off that side and watch what happens when an assistant gently eases the brake pedal down? Do you see the expected movement of both cylinders?
Don

Posted: **Sun Aug 07, 2022 7:58 am**

don58van wrote: ↑Sat Aug 06, 2022 11:22 pm It does seem that the cylinders on one side aren't working properly. Have you tried taking the drum off that side and watch what happens when an assistant gently eases the brake pedal down? Do you see the expected movement of both cylinders?
Don

I can see it moving a bit (a few mm I guess), and I can feel from rotating the drum that it’s engaged a little (it goes from easy to rotate to slightly less easy to rotate). It feels like the cylinder is just not moving enough, which seems strange on a brand new wheel cylinder.

Posted: **Sun Aug 07, 2022 8:53 am**

Someone who is more expert than I (PTH?) will be along with a better analysis than mine. As I see it, with all the other cylinders correctly adjusted, there should be almost immediate and lengthy travel of the cylinder(s) with the drum off. (Indeed you would normally have to be careful of over-travel of the pistons). It may be quite uneven between the upper and lower cylinder because of minor variations in friction--the one with least resistance will always respond first and probably most.
I would be wondering if there is a blockage affecting that corner. This might be because of a squashed pipe or a blocked flexible hose (they can swell internally when old or damaged when clamped too hard).
Don

Posted: **Sun Aug 07, 2022 9:41 am**

Another side thought. When I received the cylinders in the post one of them had a snapped elastic band (the holds everything together). I had assumed that was just superficial but as you’ve talked about ‘overextending the piston’ maybe that has happened inadvertently at some point

Posted: **Sun Aug 07, 2022 9:53 am**

Have you adjusted the handbrake cable at the handbrake? The workshop manual advises against it. If you remove too much slack from the cable it prevents the rear cylinder pushing the shoes out.

Posted: **Sun Aug 07, 2022 10:27 am**

As regards the handbrake/rear brake adjustment - when adjusting the rear brakes the handbrake cables should be slackened right off.
The snail cam should then be turned to lock the brake drum, this centralises the shoes in the drum. The snail cam should be then backed off so that there is absolutely no contact between drum and shoe when the brakes are not applied. If the snail cam is adjusted up too tight then there is very little travel of the cylinder piston which could lead to seizure. Once the snail cam adjustment has been carried out the handbrake cables can be adjusted so as to give sufficient but not excessive travel.
I would suggest that the cylinder(s) that appear(s) to be slow has the piston(s) removed and the seal(s)/piston(s) examined. If there are no other factors i.e. damaged brake hose and the piston seal appears to be ok I would re-assemble and try the brakes again.
When adjusting the front brakes tighten the adjusters to centralise the shoes in the drum, slacken off the adjusters so that there is again absolutely no contact between drum and shoe. As with the rear brakes the pistons need to travel to exercise otherwise they get stiff leading to seizure.
As Don intimates in his post above - there will always be a slow to operate wheel cylinder (even when new) which will push the linings into contact with the drum last -but giving enough movement of the wheel cylinder helps to alleviate slow piston movement.

Posted: **Sun Aug 07, 2022 10:41 am**

paul 300358 wrote: ↑Sun Aug 07, 2022 9:53 am Have you adjusted the handbrake cable at the handbrake? The workshop manual advises against it. If you remove too much slack from the cable it prevents the rear cylinder pushing the shoes out.

That’s interesting. No, I’ve not touched the handbrake it is connected but ‘off’. Perhaps that’s a mistake?

Posted: **Sun Aug 07, 2022 11:10 am**

Perhaps that’s a mistake?

Yes. As Phil says in his first sentence, the handbrake must be off AND the adjusters on the handbrake must be loosened off too. When you have finished the adjustments at each wheel, then readjust the handbrake. There must be no possibility that tension in the cables affect the snail adjustment.

as you’ve talked about ‘overextending the piston’ maybe that has happened inadvertently at some point

To clarify, I meant that the hydraulic pressure could push a piston too far out--perhaps letting brake fluid drip onto the linings. I doubt that the pistons would have been harmed because they were moving in the cylinder during transit.
Don

Posted: **Sun Aug 07, 2022 3:00 pm**

philthehill wrote: ↑Sun Aug 07, 2022 10:27 am As regards the handbrake/rear brake adjustment - when adjusting the rear brakes the handbrake cables should be slackened right off.
The snail cam should then be turned to lock the brake drum, this centralises the shoes in the drum. The snail cam should be then backed off so that there is absolutely no contact between drum and shoe when the brakes are not applied. If the snail cam is adjusted up too tight then there is very little travel of the cylinder piston which could lead to seizure. Once the snail cam adjustment has been carried out the handbrake cables can be adjusted so as to give sufficient but not excessive travel.
I would suggest that the cylinder(s) that appear(s) to be slow has the piston(s) removed and the seal(s)/piston(s) examined. If there are no other factors i.e. damaged brake hose and the piston seal appears to be ok I would re-assemble and try the brakes again.
When adjusting the front brakes tighten the adjusters to centralise the shoes in the drum, slacken off the adjusters so that there is again absolutely no contact between drum and shoe. As with the rear brakes the pistons need to travel to exercise otherwise they get stiff leading to seizure.
As Don intimates in his post above - there will always be a slow to operate wheel cylinder (even when new) which will push the linings into contact with the drum last -but giving enough movement of the wheel cylinder helps to alleviate slow piston movement.

Thank you for this. I’d not seen this when responded earlier. I will slacken the handbrake and start over!

Posted: **Sun Aug 07, 2022 7:19 pm**

I come with an update. I completely slackened the handbrake cables and started again, this time it all worked as expected. I’ve not done a road test as by the time I was finished it was time for a BBQ

Thank you everyone for persevering with my dumb questions

I suspect there’ll be many more

Posted: **Sun Aug 07, 2022 8:44 pm**

Well done.

No question on here is dumb.

Posted: **Sun Aug 14, 2022 5:29 pm**

Follow up… took the car out on an actual (slow/quiet) road and everything seems good!

It’s surprising how much more lively he seems without one of his rear brakes stuck on

Posted: **Sun Aug 14, 2022 7:18 pm**

I'm not surprised ! Makes a big difference! Good that its sorted

Posted: **Mon Aug 15, 2022 11:02 am**

Fuel consumption will improve, too!

Morris Minor Owners Club

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