Replacing NS Rear Wheel Cylinder

Post by **xpress** » Wed Jul 22, 2009 10:18 am

Hi there, I am a newbie here but not to spannering and tinkering on cars!

I need to replace the Near Side Rear Wheel Cylinder, I have never touched a wheel cylinder on a Morris Minor before. The car is a Morris Minor 1000.

I am wondering if you could help me with some advice.

Firstly I would like to find out what spanner sizes will I need for the job and other items?

And could someone briefly talk me through this, if you could tell me any little tricks to make this easier, I would be very grateful.

Many thanks.

Post by **jaekl** » Wed Jul 22, 2009 9:45 pm

I can help from way over here. Not many tools needed and very straight forward. The only tip is to loosen the axle shaft flange because it needs to move about a half inch in order to get the cylinder out.

Post by **bmcecosse** » Wed Jul 22, 2009 10:12 pm

Firstly -welcome to the Forum! If you need a (free!) copy of the Workshop Manual - PM me.
And - No - you can pop the rear cylinders out -without disturbing the hub or half shaft. Takes a little 'wiggling' - but it can be done. The only 'spanners' required are for the brake pipe fittings. Ideally - get two cylinders - and fit new on both sides of the car. Slacken off the handbrake adjustment - remove drum and shoes - disconnect handbrake cable - put plastic bag under the top of the brake fluid master cylinder (top it up first!) - then undo the brake pipe fitting (usually 7/16" AF spanner - but can vary) - wiggle the old cylinder out - pop in the new - reconnect brake pipe and handbrake cable - refit shoes and drum. Adjust up the brake till rubbing - then back off 1 notch. Connect handbrake cable - bleed brake. Re-adjust the brake at the drum - and finally - tighten up the cable adjustment to set the handbrake as you like it. Simples !

Post by **Dean** » Wed Jul 22, 2009 10:23 pm

Couldn't have explained it better myself! You'll find after spending a whole day doing the one side.... the other side you'll do in about 15 minutes.

Post by **rayofleamington** » Wed Jul 22, 2009 10:31 pm

You won't need a lot of tools - my guess is:
Very big straight blade screwdriver
Big straight blade screwdriver
Pliers
hammer
7/16" spanner (for brake pipe)
? maybe 5/8" spanner or socket for brake banjo bolt

find somewhere flat to park

chock all the other wheels securely and remove handbrake

loosen wheelnuts on offending wheel

jack up carefully and remove wheel

place wheel on top of spare wheel under car nearby where you're working (for something safe for it to land on incase something odd happens and it falls off the jack)

Round the back of the brakes, find the handbrake lever and end of the handbrake cable.

Remove split pin and remove pin to release the cable from the lever

remove boot from rear if there is one

undo brake pipe and remove from banjo bolt

Undo and remove banjo bolt

rotate drum until hole is aligned just below the bottom of cylinder - hopefully in line with the brake adjuster head.

De-adjust the brakes (turn adjuster anticlockwise)

undo the countersunk screw (if there is one) holding drum on

tap and wiggle the drum off

use the v.big screwdiver to lift the shoe up and remove the adjuster.

lift the shoes up at the cylinder and drop them off the side of the cylinder.

jiggle the shoes to remove theme from the assembly / remove springs

now the easy bit - slide the cylinder to the top of the slot and tap it out of the slot

Remove cylinder completely using hammer - give it a litle tap with the hammer to ease it past the hub.

Re-assy is pretty much the same in reverse order, but:
1) the copper washers on banjo may need cleaning up
2) the brake pipe might not have survived being undone
3) pre-fill the brake cylinder with brake fluid
4) make sure you fit a new boot to the rear of cylinder / handbrake lever
5) adjust the brakes up and test without re-attaching handbrake cable
6) when refitting handbrake cable make sure it's not pulling the brakes on.
and don't loosen/move the axle flange as it could damage the gasket.

Post by **d_harris** » Wed Jul 22, 2009 10:54 pm

3 is a good Idea Ray. However, as the pipe union is at the bottom wont it all leak out?

Post by **rayofleamington** » Wed Jul 22, 2009 11:01 pm

However, as the pipe union is at the bottom wont it all leak out?

handbrake lever is at the bottom - pipe is near the top. Some may leak out but priming really helps with bleeding.

a tip I missed - if the beeding isn't right first time, de-adjust the brakes so the piston has plenty of travel. Pump it up and push it back a couple of times will help to flush any remaining air out of the cylinder.

Post by **Leo** » Wed Jul 22, 2009 11:30 pm

Some pattern rear wheel cylinders (QH for example) need the half shaft loosened to get them to fit.

Leo 69 Traveller

Post by **bmcecosse** » Thu Jul 23, 2009 2:00 pm

I've never 'pre-filled' a cylinder - and never had the slightest bother bleeding them either.

Post by **katy** » Thu Jul 23, 2009 3:45 pm

put plastic bag under the top of the brake fluid master cylinder

Could you please explain this in detail and the reasoning behind it.
TIA, Ken

Post by **xpress** » Thu Jul 23, 2009 3:56 pm

I am going to get out my old imperial spanners and dust them down. I just want to say thank you to everyone for their help, I think I am going to like being a Morris owner, you're a great bunch, cheers!

Post by **bmcecosse** » Thu Jul 23, 2009 4:44 pm

The master cylinder is filled right up - thinish plastic bag placed on the opening - and top refitted. This 'seals' the cylinder and minimises (usually totally prevents) any fluid running out while changing the slave cylinder. Obviously won't hold for 'ever' - so you have to get on with the job. When all reconnected - remove bag - and bleed the cylinder as normal. Often it just starts running through - complete with air bubbles - sometimes you may need to assist it to get the flow going.

Post by **MarkyB** » Thu Jul 23, 2009 6:01 pm

If the gods are smiling on you and the pipe doesn't twist when you start to undo it then I just run it back far enough to Allow the big fitting to turn then undo that.
It is vastly easier to thread this back into the cylinder than to thread the pipe fitting in.
If someone has overtightened the pipe fitting this can be almost impossible.
Easier to do than explain, but very worthwhile if the pipe is in reasonable condition.

Post by **bmcecosse** » Thu Jul 23, 2009 7:52 pm

Good point there MarkyB - quite right! It's a while since I did one of these - and that IS much easier, I had forgotten.

Post by **katy** » Thu Jul 23, 2009 8:44 pm

I kinda figgered that was what it was about, but I'd never heard of that procedure before.
Makes sense to me.
Ya learn somethin every day.
Thanks, Ken

Post by **rayofleamington** » Thu Jul 23, 2009 9:21 pm

It's a while since I did one of these

it must be many years! especially when trying to gravity bleed a cylinder full of air that doesn't have a bleed nipple.

plastic bag/clingfilm tip works better on modern cars, but for a Minor you only need some bluetack/chewing gum over the minute vent hole in the cap.

Post by **bmcecosse** » Thu Jul 23, 2009 9:23 pm

It works Ray - it works!

Post by **xpress** » Fri Jul 24, 2009 9:46 pm

Hi there folks, I have found the two spanners the 7/16" and the 5/8", I am going to do it this weekend weather permitting!

If I am topping up the master cylinder, what oil do you recommend me to get that will be compatible with the stuff already in there?

I have just thought of another question, where would safe trolley jacking/axle stand points be on these babies?

Thanks again!

Post by **rayofleamington** » Fri Jul 24, 2009 10:41 pm

what oil do you recommend me to get that will be compatible with the stuff already in there?

technically speaking it's "hydraulic fluid", not oil, but that's just being picky

Some bog standard Dot3 or Dot4 brake fluid will be fine.

I have just thought of another question, where would safe trolley jacking/axle stand points be on these babies?

if using a scissor jack, the axle mounting plate (the one with the U-bolts through it) gives a good flat surface for jacking. Trolley jack may not fit there.
Axle stands go under the axle. I've always thought it best to put them as near to the spring as possible.

Post by **bmcecosse** » Fri Jul 24, 2009 11:10 pm

Yep- ONLY jack under the suspension components - never on the body.