Ok, folks. After over 50 years of working on cars, I have to admit I'm stumped with this problem. Rather than bleed my brakes the old-fashioned way, I made the bold step to buy a Harbor Freight vacuum bleeder that works with my air compressor. Attach the compressor to the bleed bottle, turn on the compressor, release the bleed screw and fluid will get sucked wonderfully through the tube into the bottle removing all air from the system. Simple, right? Except it's pulling almost nothing thru the tube when operating -- literally just a drop or two. I've checked the vacuum hose and it is indeed pulling a vacuum and should, on the surface, be doing its job. But, it's just not. I've attempted both rear brakes, starting with the right side back first -- nothing either side. It's almost as if the fluid is somehow restricted from flowing. Anyone have any brilliant ideas on how to approach this conundrum? If not, I'll have to use the fall-back of having someone pump the brakes and I hate to do that after spending the money for the "new & improved" tool.

 

I recently did the poorman's JCW brakes and also had a hell of a time. I too had the HF kit and at first, it worked then didn't. I reverted to the pump, hold, I SAID HOLD.....What? procedure. I think it has something to do with the ABS module. Not 100% sure but in the end just completed it the old fashioned way. I think if you have the Schwaben scanner you can cycle the ABS module and then use the HF kit.

 

I know other people have succesfully used vacuum bleeders on these cars, so I don't think that's the problem. You did remove the cap, right? it's vented so you ought to be able to vacuum with it on, but still would be easier with it off.

 

I did. the HF system has a gravity feed filling bottle that keeps the reservoir full. In order to do that, you have to remove the cap. That all being said, I might have screwed up the procedure and that might be why I had trouble.

 

I used to use a MightyVac tool to bleed my brakes but found that I was seeing air bubbles and very little brake fluid. Finally realized that the air was coming from around the bleed screw which may be the OP's problem. I "graduated" to a Motive Pressure Bleeder and have had no such problems. Seems that "PushMe" is better than "PullYou".

 

Reference Lotter1's post: cap was definitely off due to the supplemental reservoir HF system. It just makes no sense that no fluid is being extracted since fluid must be present for the caliper to work. I'm going to replace the bleed screws (with speed bleeders if I can find the right size) that theoretically could be restricted to see if that fixes it. Update later.

 

He may be correct as I've seen them pull through the bleed screw threads rather and actually pulling air.

I would recommend the Motive bleeder as it is much easier
https://www.waymotorworks.com/brake-...r-bleeder.html

Or just bleed it the old fashion way

 

After some research, I'm learning that the ABS and DSC systems may be a bleed barrier and that dealerships using a coding device to activate the ABS pump in order for the fluid to flow. My MINI is a 2004 S with both features. Is there a method to overcome the coding step?

 

I have a pressure-type bleeder similar to the Motive unit which works flawlessly.

 

+1 - once you've used a pressure bleeder you will never bother with anything else again.

 

ABS module has nothing to do with bleeding brakes UNLESS you get air in the system. Pressure bleeder works best. To do a full flush you do need a shop that can cycle the abs module, otherwise that fluid never gets flushed.

 

+1 again for the Motive pressure bleeder. Love it. An introvert's best friend when bleeding brakes.

 

You ONLY need to use a computer to activate the ABS for bleeding if you replace the ABS unit. Otherwise just doing normal bleeding is all you need. I can tell you that in the last 17yrs of working on these cars I rarely if ever need to use that function and it's never for just a brake fluid change.

 

Never used my vacuum bleeder on my Mini but when I used it on my truck I had to put some teflon tape on the bleeder screws. Without the tape I was pulling a lot of air and very little fluid.

 

I have the little Harbor Freight vacuum bleeder here ....... I used it to bleed both my '04 R53 and my '06 R52 JCW cars......they all bled out just fine.....no problems....even used it to bleed the clutch slave cylinders as well

Bryan

 

Hey, I am experiencing a similar issue after replacing the rear brakes lines on my 04 mini cooper s. I’m trying to vacuum bleed but not fluid is coming to the rear. Did you happen to figure out how to get the fluid to be able to travel to the rear for bleeding? Iv tried compressing the rear calipers and a few other things but have had no luck? Any advice helps!

 

You should be able to just pedal bleed it.

 

the fault started with the right rear corroding and causing a leak. I think a safety feature is not allowing brake fluid to that rear caliper. I’m not sure if it’s a proportioning valve stuck or my abs unit not allowing fluid to get back to the right rear but Iv tried vacuum bleeding and the 2 person method and no luck getting any fluid to the right rear caliper!

 

As far as I know there’s no safety feature that would cause that behavior. As has been mentioned, you shouldn’t have to touch the ABS unit to bleed the brakes unless you’ve gotten air into it, in which case you have to either put it into bleed mode or chance going out and activating it to pump the air out. I assume you’ve tried bleeding with the bleeder screw removed and/or the hose disconnected from the caliper?

 

I've never experienced your/this particular issue myself but one of the contributors here had posted a similar problem in one of his R53 threads -
Apparently he discovered crud and corrosion built up in his brake lines, preventing anything but a few drops of fluid to purge as a result.
Perhaps this might be the the same/similar cause?