34 replies to this topic

[JXC Mini GT]

So am i right in thinking that your 1980 gt will not have a brake servo.

I trust also that since most of the brake system has been changed you have changed the fluid right through.

Are you loosing any fluid from anywhere.(usually this appears in the form of bubbly paint work where the paint is eaten by the fluid..)

Is it a single line or a twin line.

I would also suggest making sure that the rear wheel cylinders are the correct ones as have had issues before with travel in the rear wheel cylinders. Have you got dry drums on the rear if they are wet then your fault is found..

Also had issues with front hoses and full lock. Some are short and split over time when full lock is on steering causing them to split slightly and allow air into system..


Look at the whole system not just the bit you think is faulty...

Good luck either way.

Thanks for the suggestions.

No Brake Servo, all fluid changed, no leaks, rear wheel cylinders were changed a number of years ago and drums are dry, front hoses were changed a year ago and just to make sure they're not the problem are being changed again, tandem master cylinder 1 line serving front 1 line serving rear..

This problem has recently occurred.

Edited by JXC Mini GT, 26 March 2021 - 01:04 PM.

[JXC Mini GT]

 

 

There are / were shims available that are fitted under the mounting flange of the Master Cylinder, effectively raising it.

A quick test you can do to see if this is the issue is to slot 2 - 5/16" flat washers, loosen the nuts on the master, lift it, slip these washers in, then tighten the cylinder back down. You wouldn't want to leave it this way though as the Engine bay is vented through he and so it might get a little smelly or fumey.
 

 

Thank you for the suggestion, I will give that a try, fingers crossed

[sonscar]

The reason the free play is important is because the master cylinder has a small hole when at rest which relieves the pressure and allows new fluid in.Steve..

[bpirie1000]

Could always try a bleed nipple in the master cylinder to see if it holds pressure, test the cylinder that way, removing all the possible issues with the pipework..

[JXC Mini GT]

So today I followed Sonscar and Spiders suggestion and fitted a couple of washers between the master cylinder and the master cylinder base plate, this then gave some free play on the pedal.

I took it for a test run and it seems to have solved the problem, many thanks to all for the suggestions and a big thank you to Sonscar and Spider for the solution.

I am now a very happy Mini owner.