I wanted to know how to mimimize the mess when removing the damaged brake hose.  I'm thinking to open the bleeder and set up a catch, then remove the hose from the subframe first allowing it to drain out through the bleeder.  Then replace and rebleed.

I have a email out to 7Ent to see about replacing either just the backs or the enter setup.

Not sure what you mean by "brake fluid dumps out of the system".

Once you get the hoses sorted (not baggy/stretchy) and the adjusters to stay put and the level corrct, the hydraulic system should be constant and not blow back through the cap or drain down. The cap should be vented (built in) and should be allowed to vent, otherewise the action of the master cylinder will cause a partial vacuum in the reservoir making it harder to apply brakes or needlessly pull fluid back when you release the pedal, or try to collapse the reservoir (not too likely). I don't know if Mini master cylinder caps have diaphragms in them but modern masters have a soft rubber diaphragm between the vent and the fluid to keep humidity out. When you depress the pedal, the fluid level goes down in the reservoir and comes back up when you let go, except for the amount needed to make up for shoe/pad wear over time. Atmospheric air pressure presses in on the diaphragm so the vacuum doesn't occur and suck the fluid back. The cap needs no seal othere than waht it was built with, and the vent needs to be functional. You should never see the dripping observed by your wife several posts back.

Kudos to your helper for the ballon analogy.  She was spot on.  If I were you I'd replace all rubber lines with braided stainless.  It may seem like overkill with drum brakes but you would never have to worry again.  And as you've experienced rubber lines can be deceiving by looking fine on the outside but fail on the inside so your mechanic may have had no visual indication of a problem.  I think I'll have my wife work the brakes on my car with rubber lines and have a look as well.

Not to curse you but I always have more trouble replacing rear lines than the fronts.  Where the rears attach to the subframe is a bugger for me to get at.

Sorry, no recommendation on the front adjuster issue other than to contact your supplying vendor.

Ok internet folk, here is the latest. Lots of new info.

Me and my lovely assistant worked on the brakes today.  She was armed with a cozy blanket, space heater, and her knitting.  She was ready to help pump that brake pedal!  

I got all four corners clamped off so that the pedal was rock hard and all wheels would spin freely when depressed.  Then I started to inspect each corner by removing the clamp so that we would ONLY be testing one corner at a time.  

RESULTS

Fronts: Both fronts showed the same thing.  I could adjust the shoes, but then as my wife pumped the brakes i could watch the front/lower adjuster wiggle back and forth slowly moving it back out of adjustment.

Rears: I removed one clamp from the back passenger side and again had Liz pump the brakes.  She said it was firm, but felt kind like a balloon depressing.  I then had her repeat while i watch the rubber brake line. What do you know, it was pulsing like a balloon.  The other side was worse off and was now leaking from where the clamp was.

Overall, the rear rubber needs to be replaced.  I am kind of pissed the mechanic didn't recommend that or spot that.  Those seem "easy" to replace and then rebleed. If i keep the cap on the MC should that limit how much brake fluid dumps out of the system?

What do i do about the front adjusters???

Again, thank you all for you help. 

Sorry that wasn't clear.  The symptoms were unaffected when i clamped off the rear brakes.  The handbrake was disengaged when adjusting the rear brakes.  The wheels would be free to move when the hand was down.  

Do I understand this correct? The problem went away when the rear brake hoses were blocked off?

In that case, the problem must be with the rear brakes. Probably a case of adjustment as mentioned before ;-)

Did you release the handbrake cable completely loose before adjusting the brakes? Are the handbrake actuating levers in the backplates and the quadrants on the trailing arms free to move?

Cheers, Diddi

Well, there was a Cooper S can in there before (not that it means it was right), but i think i read that the inoocenti used some of the Cooper S parts in the MKIII car.

I am pretty sure the problem happens rolling or on jacks.  Its on my list to test.  Speaking of which, here is my current list

1. Jack up car and adjust front wheels.  Simulate braking 3 or 4 times to see if symptoms return.  This will demo if it only happens while driving

2. Assuming problem persists. Re adjust brakes and then watch adjusters while wife applies brakes 3 or 4 times or until symptoms return (this could be done at the same time as step one.

3. If adjust don't move, then clamp off all 4 corners of car, recheck for brake feel.  Then remove one corner at a time until symptons return

4. Buy disc brake conversion kit

Just reading through the thread and I noticed that you have fitted a new cooper s master cylinder? Is this the correct bore dia. to suit your drum brakes? Also if the broblem only shows up when actually driving the car check the drums for ovality (out of round) as when turning they would push the shoes back into the wheel cylinders and cause the long short pedal problem.

correct about the mechanic doing the MC install. I only have two clamps, but they are cheap and available locally, so i will get 2 more.

I am guessing the mechanic changed the master cylinder otherwise you would remember the clevis pin as it is tricky to install. It is visible under the dash, you may find it best to remove the drivers seat and lay on your back to inspect it. I have seen Mini's with it left out altogether.

Clamp off all four flex lines and use a rag and vise grips to avoild hose damage if you do not have enough clamps then release them one at a time to see at which corner the problem exists, just a process of elimination.

I'll go take a look at the pin.  Is it visible from inside the cabin?

I blocked off the rear two hoses and then then the front two hoses.  If i recall the issue went away when only the front brakes were engaged.

Just to throw another idea out there (may not be relavent); but how does the clevis pin between the pedal and master cylinder look?

If I remember right the pin rotates as you repeadetly push and release the pedal.  If the clevis pin is oblong that may account for varying pedal travel.  But as I type this I'm thinking an oblong clevis pin may not allow itself to rotate as easily.  Hmmm...

Clamping off all four lines to isolate the master cylinder sounds like a good idea.

Have you tried blocking off all four flex hoses to see where the pedal is ? Looking at your video it seems like either adjustment or air in the lines is the problem. Some Mini's i have had to bleed at every connection to get the pedal right and i think i suggested that a while back, did you try this ?

Right, I do believe that backs are adjusted correctly (i had to take apart the adjusters a few weeks ago). After that experiance they didn't seems to be coming out of adjustment, though i will double check to be certain.  Wife gets home in a a few hours, so i will retest when she gets home.  She will be soooo excited!

But on the 1st stroke, the pedal went down quite far. Actually close to the floor. And on the 2nd stroke, it was OK.

And it at least seems to hold the pressure.

This definitely indicates, that there is a problem with the adjustment.

Either at the front or maybe also at the rear end.

Especially at the rear end, the feeling during adjustment is often misinterpreted.

The adjuster bolt has a pyramid-shaped tip and has to be turned 1/4 turn each time and then "centered" about in the middle between the 2 "ramps".

If this is not done, pressure on the shoes, created by the wheel cylinder may allow the adjuster to rotate slightly (if quite loose) and unadjust the rear brakes.

Cheers,

Diddi

I retested the pedal and I don't think it is falling at all.  I gave it what i approximated the same amount of pressure for 45 seconds and the pedal barely moved at all (if any).  

Maybeing seeing how I get pressure will help diagnose the issue.  Once my wife gets home I will put the car up in the air, adjust the brakes, then have her pump the pedal to simulate braking and I will watch the adjusters.  

It seems like you may have found the problem finally. Sometimes when renewing parts you naturally take for granted the new parts purchased are good but unfortunately that is not always the case and you chase your tail for a while then backtrack and find the problem. If there is a new or rebuilt option i would spring the extra cash and go with the new one, you don't want to have to pull it off again as it is not the easiest of jobs on a Mini.

@zippypinhead

Nope, I don't have the original any longer

@h_lankford

Yeah, I think i bought the master cylinder from MiniSpares, so I am going to ask them about buying a new one and returning th old one.

the cap does not "see"  brake hydraulic pressure. it is not the problem

After all this time, I'd look at the answer as a diagnosis not made yet.... although I think someone else mentioned this earlier... if it were me, I would replace the master cylinder, no matter whether it is new or not.