Morris Minor Owners Club

On my 52 4-door MM, the brakes are binding after about 4 miles running. At first they are fine, the car moves easily but soon they begin to bind. You'd think with such a simple system that this would be a fault easily found, but.....

Any suggestions welcome, I'm supposed to be using the Morris to take a friend to get married in a couple of weeks, so the pressure is on!

Mike

Have a feel of the hub caps after they have been binding for a bit.
The warm ones are binding.
If they all seem about equal it could be a master cylinder problem.

If it is just one or two sticking wheel cylinders (due to not much use) a few stamps on the brake pedal can free them off. Otherwise you will have to free them off manually and give them a smear of red grease to stop them sticking in the future.

Series MM front brake cylinders are prone to sticking or seizing, particularly if the car is left standing.
Jack the car up and remove the brake drums. Do one wheel at a time and replace the drum afterwards. Check that both cylinders are opening and fully returning.
When you have found the faulty cylinder the piston can be removed and cleaned, particularly around the cap. Smear with Rubberlube brake grease, reassemble and test.
I have managed to clean and re use pistons which were stuck solid.
New cylinders are available from Bull Motif.

Check where the edge of the brake shoes rub against the backing plate. If neccessary, clean and put a SMALL amount of grease there.

Thanks for all this,

Mike

Oh dear. I've had a look 'round the brakes themselves and found one of the front wheel cylinders very siezed, one stuck and one leaking. To be honest, all bar one of them look pretty rough. I was also concerned at the way one of the pistons did not want to be pushed back against the fluid in a way that I felt that this was a problem with getting the brake fluid to go back up to the master cylinder rather than a problem with the wheel cylinder itself. (I hope that made sense). Obviously I have some serious phone calling to do tomorrow as well as some more head scratching.

Mike

You have two options. Replacement s/v wheel cylinders are about £30 each from Bull Motif and you might as well buy all four, or you can replace the back plate and cylinders on both sides with a 803/948 backplate and cylinders and keep the original drums

That's interesting. I'll check with our local Morris specialists and see if he's got a pair of backplates - it would perhaps be a better long term option. Thanks for that. I had wondered about later cylinders but wasn't sure if they'd work with the existing drums. Do you have to shorten the wheel bolts or anything like that?

Mike

I haven't done the mod. myself but I am assured that the backpate and cylinder assembly is a straight swap. The advantage is that the wheel cylinders are about half the cost. The only point to watch out for is to check that the brake pipe threads are interchangeable if you need to swap any over. I think that the threads on the flexible pipes are OK.
The problem with the pistons not retracting properly was probably because they were pushed out further than normal when you checked them. Normally the the spring tension would be enough to retract them

Hi
I did the conversion . Very easy to do . I think I got a new copper pipe for between the two cylinders at the same time not sure about the flexipipe as I got a new brake pipe set but I think I ordered a set for my sidevalve and just ordered new pipes for the front wheels
Ian

ian.mcdougall wrote:Hi
I did the conversion ....
Ian

I've now got all the bits together, new cylinders, backplates, flexi and copper pipe + various nuts and bolts, so it's going to happen. Ian, can you remember if you had to shorten the wheel bolts? When I temporarily fitted a later type cylinder on the back last year the bolts grazed it. Obviously I'll check on the front when I put it all together, but I wondered if you remembered.

Mike

Compare the diameters of the cylinders. If they are the same diameter then the wheel bolts should not be a problem. If they need shortening then wind a nut onto the bolt before you saw the end off so that the thread is cleaned up when you wind the nut off the bolt.
Check the depth of the wheel and drum holes so that you do not cut too much off.

Hi Mike
did not have to shorten wheel bolts have you got the original bolts
ian

ian.mcdougall wrote:Hi Mike
... have you got the original bolts..
ian

Hard to say, but I'll let you know how I get on. Going back to the original post, the car is supposedly delivering a friend to her wedding on Saturday 31st, hence the mild panic! I'm taking Tuesday off work to do it - in the bride's brother's garage and the groom is coming to help me bleed the brakes....

Mike

Squirt the back plate nuts and bolts with plus gas and leave them to soak. I think they are 1/4 Whit. so have a ring/combination spanner and socket handy. Once the old assembly is off there should be no problems with the new set. They are easier to fit on the MM as you have not got the large hub assembly to get in the way.

Did the job on Tuesday, am now keeping fingers crossed for Saturday and the wedding run. The journey involves a climb out of Darwen to a chapel on the top of the Pennines followed by a descent of same to the reception. Just the job for an MM.....................

Mike

Check the handbrake!!!!!!!!!!

Job done. Everything went well - even the weather, which isn't bad for the Pennines. Thanks for all who helped.

Mike<br><br>

Looking very good!! I bet the brakes felt much better to....