Brakes..another brake thread

Started by tmsmini, August 28, 2016, 09:29:34 AM

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tmsmini

So now that a portion of the brain trust has immigrated to RM...
I have had this car on the road for about a year and the brakes while they work fine, really require one pump to get a solid feel.

I have bled with pressure without pressure, cracked open junctions and I always get clear fluid. I thought maybe I had the drums setup wrong, I thought maybe the e-brake levers were causing a problem.

This is a single line 64 wagon that has been "restored." I replaced some aging 7.5 with a new set of aftermarket 7.5,  I replaced the balance valve at the back with a "new" version, I replaced the wheel cylinders, new lines as well.

Before we restored it I had replaced the master, but then it was off the road for a few years ago. With having to disconnect the brakes for this weekend's "fun with rack swapping," I am going to replace the master as well.

If that does not help I will be back with more questions.

MPlayle

Have you verified the rear brake shoes are positioned correctly?  If one is flipped, it will give that kind of feel or a soft pedal.


tmsmini

I plan to recheck again, but I am sure they are oriented correctly.

94touring

I'm actually suffering from this right now and about the only thing left to replace would be a couple old brake hoses.  I'm wondering if they are expanding under pressure.

MPlayle

Tossing this idea out for whatever ... (based on Dan's comment)

Could the hoses be starting to collapse inside and the first pump opens them back up and then the second pump works the brakes?


CraigD

Shoot, I thought it was just me! I swapped out the old twin leading shoe fronts with 7.5 discs and it still takes a pump or two to get really firm brakes. Sorry, I have nothing constructive to add.

tmsmini

I have not got back to the brakes as I ran into a few issues when doing the rack swap.
Rack and subframe are in place, just need to recheck everything, reconnect and then do the brake master swap.

94touring

When I convert to disc and if I still have to double pump, I will look into the master not sealing properly.  Mine can be erratic.

tmsmini

I have new braided teflon "hoses" on the car with the issue and the old rubber on the other car feel solid.

The pictures show the most recent discovery, tapered washers with cracks.


John Gervais

That looks pretty bad, but I wonder if it'd have any real safety issue associated with it until it fragmented and jammed into the bearing.   :-\
- Pave the Bay -

tmsmini

Yes, I was wondering that as well. IF it maintained itself in the taper, it would still hold the bearing place for the most part. If it fractured and allowed the nut to loosen, then who knows.

MiniDave

I don't think it can come out of there even if it broke along those cracks...it's too tight a fit. Have to admit I've never seen one crack like that, wonder why it did?
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

tmsmini

There is a thread on "that other Mini site" about the castle nuts.
It seems there are some with the opinion that the 180 foot pounds is too high for the single hole CVs.
I have used 180 on all the single hole CVs I have had over the years, sticking to the lower value for the older versions. I think I have replaced them all with single hole versions at this point.

Maybe that caused it, somehow doubt it though.
Seven has a high quality version of the tapered washer that they sell. I have replaced with those.

MiniDave

I've always used 150lbs, then tighten to the hole....so who knows what the actual torque value winds up?
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

BruceK

#14
There is also the method of tightening to 150 ft lbs, not fitting a cotter pin, then very gently driving around the block to apply some real-world side loads so as to make sure the tapered washer is truly seated, returning to the garage to finish up by then tightening the nut to the next hole and fitting a cotter pin. 
1988 Austin Mini
2002 MINI Cooper S
1992 Toyota LiteAce (JDM)
1997 Jeep Wrangler Sahara