Classic cars forum & vehicle restoration.

Rosco663 · Joined: 17 Dec 2012 Posts: 257 Location: South Australia

Gidday all,

I am trawling for info once again Wink

I have refitted the master cylinder to Morrie, connected new brakelines & hoses and have filled and bled the brake system but the actuation of the master cylinder doesn't look right to me and seems to be lacking enough stroke or adjustment. And operating a wierd angle Shocked

When I took delivery of Morrie the master cylinder pushrod was incomplete - there were only two pieces left: the ball socket on the end of the threaded rod attached to the end of the brake pedal and the lock nut. The ball socket itself was quite worn which would not have held the ball piece. Over time the rubber boot had disintegrated and the remaining portion of the pushrod was lost to Mother Earth. I did order a complete master cylinder pushrod complete with ball joint that suited models TA,B & C MG's in the belief it was the same as what was required for the Morris.

Part number H49.

When fitted to the brake pedal and having full thread engagement the pushrod end required about an inch of travel before contacting the centre of the piston (part number H41) before any brake fluid was compressed. Also as the pedal/pushrod/piston started to compress the fluid the angle became fairly extreme and also the remaining travel was not sufficient to fully activate the brake wheel cylinders.

So here comes my humble request - can anyone send me a picture of their setup and if possible measure up the pushrod assembly for me to compare ( Including total thread length - where it attaches to the end of the pedal, ball joint section length and rounded portion length) . Also is there any adjustment available/recommended to get the actuating angles more in line???

Cheers from the very confused
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Rosco

bjacko · Posted: Wed Apr 02, 2014 5:48 am Post subject: Morris 8 Master Cylinder Push Rod

The rod is 6" long including ball end, with 1 1/4" reduced diameter and rounded end which fits in Master Cylinder, then a 1" plain section, plus flanges for boot about 3/8" wide.
The threaded coupling with ball cup is 1 15/16" long with 1 1/2" thread which is 3/8" BSF thread.

Rosco663 · Joined: 17 Dec 2012 Posts: 257 Location: South Australia

Thanks very much Bjacko for your help - it would appear that the setup for mine is too short.
I will need to rectify this in the future.........Is it possible to take a snap of the setup with the pedal up and also fully depressed so I can see the angles involved?

Cheers
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Rosco

bjacko · Posted: Wed Apr 02, 2014 6:14 am Post subject: Morris 8 Master Cylinder

further to previous.
The push rod for the Morris 8 is part number 3988 whereas the MG TA, TB, & TC is 8100. These are Lockheed numbers.
I can take the photos but I have difficulty uploading the pictures to this forum. Send me an E-mail address on moreg Victoria website under manuals

Rosco663 · Joined: 17 Dec 2012 Posts: 257 Location: South Australia

Thanks mate - email sent Wink

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Rosco

goneps · Posted: Thu Apr 03, 2014 4:22 am Post subject:

Rosco,

A couple of pictures for you (excuse the mud):

I suggest you obtain a new pushrod assembly from Ian Harris in England:

ian@harris84.fsnet.co.uk, tel: +44 146 245 6330

He's a popular source for MR members in Britain, knows his Morrises, and gives good quick service. Also has PayPal.

Don't take a chance with this component. If the ball joint becomes detached in service you'll have no brakes. Bloody dangerous and just not worth the risk.

Further to Bjacko's info., you'll observe that the master cylinder sits in a slot in the chassis cross-member. If you position it too high in the slot the pushrod can press on the bottom of the piston and cause it to bind in the cylinder. On my car it needs to be as low as possible to prevent this.

Richard

Rosco663 · Joined: 17 Dec 2012 Posts: 257 Location: South Australia

Thanks for the advice Richard, I reckon I will go ahead and order the correct item from Ian and a few other bits and bobs. And his catalogue number is the same as Bjacko stated 3988. Brakes are definitely one thing that needs to be 100% sound.

I notice your brake switch is in a different position to mine. Mine actually mounts on top of the crossmember almost directly above the master cylinder and is actuated by a long spring pull. I guess there is was a fair amount of 'Artistic License' back in the day Cool

Cheers
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Rosco

goneps · Posted: Thu Apr 03, 2014 8:43 pm Post subject:

Your brake light switch is correct, Rosco—mine's not. The long spring of yours would be hooked through the small hole above the pivot of the brake pedal. Just one of many things done badly by the 'restorer' of my car in the 'seventies, which I've spent the last thirty years fixing one by one.

Richard