12 replies to this topic

[eilz1999]

Hi, I have a 998 mini (1980) which has been in the garage and stationery for years. I'm a novice but in the process of getting it moving again. I've managed to get the engine running and moving a little but I need to be confident of the brakes before going any further. Here is where the problem lies...

 

Its the black tag master with drums all round. To begin with, the system held pressure but several of the wheel cylinders had corroded and the brakes didn't work. I need to overhaul the system. I've replaced all wheel cylinders, flexi hoses (apart from 1) and a couple of the metal pipes. New shoes are on all and I've cleaned the drums up. I believe I've adjusted the shoes up as per the Haynes manual. I've put new fluid in and bled the system with eezibleed. When I use the pedal, I get pressure (and it holds) but only on the second pump. If I let go an leave if for 10 seconds, the same thing happens again. Why cant I get the pressure on the first pump? If the master is suspect, Is there a way of checking it before doing this? Any help will be much appreciated!

[Spider]

As it holds pressure, I'd say all the parts are OK, it just needs bleeding (again). Now you've got the system 'primed' try bleeding the old fashioned way, the Gunson's Ezibleed are really good, I use one, but I have also had a few cars where the Gunson's just couldn't 'finish' the job. After bleeding the old fashioned way, no issues.

 

<edit: What type of pressure valve is fitted to shut off the rear brakes?>

Edited by Moke Spider, 16 March 2015 - 09:06 PM.

[myredmini]

I would double check the back brakes are fully adjusted properly, I had these on my mk3 when I bought it and the fears needed adjusting!

[eilz1999]

This photo shows the master and the pressure valve for the rears. Hope this helps and thanks for the replies so far. Anymore suggestions will be very welcomed!

Attached Files

•  image.jpg   44.1K   17 downloads

[cal844]

Make sure you have the brake adjusters set up correctly. Id also suggest rebuild the Master cylinder imo as the seals will be perished.

HTh

[Dan]

I would agree it sounds like classic symptoms of a failed master, but you won't get a rebuild kit for a black band cylinder. Spares support for them ended in the early '80s when they became the subject of a service replacement bulletin. They were all supposed to be swapped for yellow band cylinders which in all likelihood is what you will have to do now. Try adjusting and bleeding first by all means but I don't think it will gain you very much.

[Spider]

If it is found that you do need a kit for the M/C and can't obtain one locally, we still have them widely available here.

[dklawson]

You said in the subject line that you get a firm brake pedal on the 2nd pump.  Does that also mean that on the first pump the pedal goes almost to the floor?  When you pump the pedal the second time and keep pressing the pedal... does the pedal stay where it is or does it slowly sink to the floor?

[cal844]

I would agree it sounds like classic symptoms of a failed master, but you won't get a rebuild kit for a black band cylinder. Spares support for them ended in the early '80s when they became the subject of a service replacement bulletin. They were all supposed to be swapped for yellow band cylinders which in all likelihood is what you will have to do now. Try adjusting and bleeding first by all means but I don't think it will gain you very much.

. I knew there was a bulletin but couldnt remember which MC it covered

Thanks Dan!

[eilz1999]

Thanks for all thr replies. Dklawson the pressure holds on the 2nd pump so i will give further bleeding and adjusting a go and then look at the master. Moke spider, where can i get a new master kit if i need them? Thanks again for all of your suggestions!

[Spider]

Thanks for all thr replies. Dklawson the pressure holds on the 2nd pump so i will give further bleeding and adjusting a go and then look at the master. Moke spider, where can i get a new master kit if i need them? Thanks again for all of your suggestions!

 

PM sent

[FlyingScot]

I would agree it sounds like classic symptoms of a failed master, but you won't get a rebuild kit for a black band cylinder. Spares support for them ended in the early '80s when they became the subject of a service replacement bulletin. They were all supposed to be swapped for yellow band cylinders which in all likelihood is what you will have to do now. Try adjusting and bleeding first by all means but I don't think it will gain you very much.

Below the service bulletin referred to by Dan above
 image.jpg   95.8K   8 downloads

FS

Edited by FlyingScot, 17 March 2015 - 11:51 PM.

[Spider]

 

I would agree it sounds like classic symptoms of a failed master, but you won't get a rebuild kit for a black band cylinder. Spares support for them ended in the early '80s when they became the subject of a service replacement bulletin. They were all supposed to be swapped for yellow band cylinders which in all likelihood is what you will have to do now. Try adjusting and bleeding first by all means but I don't think it will gain you very much.

Below the service bulletin referred to by Dan above

 

FS

 

 

*** This relates to the situation fitting these Master Cylinders in Australia, I don't know what the deal is in other countries, I would suggest it best to check***

 

The fitting of the Yellow Tag Master Cylinders is not actually legal in this country. Now, I'm not saying they are no good or anything remotely like that, it comes down to a compliance issue with our rules:-

 

 

Because the piping has to be re-routed and the Front Brakes are fed via the top of this Master Cylinder, the Reservior doesn't have enough capacity to meet the requirements of this Rule. This has been the case since pretty much the year dot here.