Cracked pedal bracket, and then some...

[1st 5er]

more problems.

Drove the Snob, DJ's old 86 535i, to get it inspected and on the way home, the pedal went to the floor and stayed there for about two blocks.
Then it pops back up and I make it home.
I changed out the cracked pedal bracket and now it won't go into gear and the pedal still wants to stay on the floor.
I installed a new over/under spring last week.
Everything is back together as it should be.

Not sure how long it sat up at his house, but it's been close to a year sitting at mine.

I'll bleed it tonight and see what that does.

Damn, the clutch fails on the E12, in Bland VA no less, and now this.
And it hasn't rained at my house since March, and that was only like a 1/4 inch.

[wkohler]

My red car did this last night. Except there's brake fluid everywhere. Check for that.

[1st 5er]

That was the first thing I checked, reservoir was full, everything is dry.

[Kyle in NO]

If it's not leaking from the slave cylinder, replace the master. They don't always leak when they fail. Funny to note that the master in my 533i has been leaking for about 5 years and still works fine!

[1st 5er]

...replace the master.

That's just the job I've been dying to do.
Just needed a good reason.
So, this is it?

[Brad D.]

I had a bad pedal bracket kill the master just like you are describing. Replacing it should fix the problem.

[1st 5er]

When I replaced the broken over/under spring several days back,
I discovered the master cylinder was attached to the outside of the pedal bracket.
I switched it to the right side, but evidently too late.
That I think, was the beginning of the end.

New master in hand, now to the fun part...

[JW in VaBeach]

Get r done Sherman

[1st 5er]

[Karl Heinz]

Worst part of changing the master is getting the hard line on from under the car. Well, at least it was for me. I would also recommend doing the slave at the same time, while taking a good hard look at the line going from one to the other. The line on Karl Heinz was just about to rupture, as evidenced by the bubble coming through.

[1st 5er]

Got 'r done.

Replaced the master.
Installing the hard line before bolting it to the bracket is the easiest way I've found.
It helps to have long arms, though big hands are a bit of a hindrance.

While bleeding the system, without any signs of success,
the pedal, all at once without warning, got rock hard, wouldn't depress at all.
The slave plunger had detached itself from the slave cylinder.
A steel part and an aluminum bellhousing made extracting that part a breeze.
Harvested the one from the disabled E12 and installed it.
Now it works great, except that it engages a bit lower to the floor than the others in the herd.
I'll re-bleed when a helping hand is close by.

Based on that experience, which was faulty initially, the master or slave, or both?

Thanks for the feedback rude-asses.

[C.R. Krieger]

Worst part of changing the master is getting the hard line on from under the car. Well, at least it was for me.

That's why you do it from the inside. The hard line will flex enough to get the fitting inside ...

[1st 5er]

...more... again.

Now it works great, except that it engages a bit lower to the floor than the others in the herd.
I'll re-bleed when a helping hand is close by.

Based on that experience, which was faulty initially, the master or slave, or both?

Re-bled... release still remained too close to the floor.
Drove it Monday, Tuesday, without incident, and then today...
Early this morning the pedal stayed on the floor while I was stopped at a light.
I pulled it up and it worked OK, though still close to the floor, for a while longer,
and then at every stop after shifting into first, it'd stay on the floor.
Being the improviser that I am, I took my umbrella, which has a small rope attached to the handle,
and hooked it around the pedal each time I was stopping and then pulled up on it, using my foot to control the release rate.
Finished my day using this hand/foot release system. What a pain.
After taking off in first it would come up by itself when shifting through the remaining cycle,
because pushing the pedal all the way to the floor was not necessary.

Bottom line:
New master ordered along with a new slave.

[Mab1957]

When I replaced the broken over/under spring several days back,
I discovered the master cylinder was attached to the outside of the pedal bracket.
I switched it to the right side, but evidently too late.
That I think, was the beginning of the end.

New master in hand, now to the fun part...

IIRC our 87 535is has the MC on the outside of the bracket. What do you mean "right side" and does the over-center spring line up with it's receiver when you're on the inside of the pedal bracket? If MC is out of alignment with the pedal wouldn't it be subject to failure? (Hence the common cracked pedal bracket stress issues).

[skip535i]

How did you bleed it? I used Kyle method (found it using the search function). Basically you let the slave out of the bellhousing and pump it by hand....

[1st 5er]

When I replaced the broken over/under spring several days back,
I discovered the master cylinder was attached to the outside of the pedal bracket.
I switched it to the right side, but evidently too late.
That I think, was the beginning of the end.

New master in hand, now to the fun part...

IIRC our 87 535is has the MC on the outside of the bracket. What do you mean "right side" and does the over-center spring line up with it's receiver when you're on the inside of the pedal bracket? If MC is out of alignment with the pedal wouldn't it be subject to failure? (Hence the common cracked pedal bracket stress issues).

Not referencing the part of the bracket that that bolts to the firewall,
but rather the small arm that attaches to the MC plunger.
It was attached on the left side of the arm rather than the right,
so the plunger was at an angle when going in and out of the cylinder.
Yes, this, IMO, causes premature failure of both parts.

The over-center spring is indeed attached correctly and sitting smoothly in the groove on the bracket.

[1st 5er]

How did you bleed it? I used Kyle method (found it using the search function). Basically you let the slave out of the bellhousing and pump it by hand....

Both ways.

Went out last night to move the car and the clutch pedal worked as it should but was still engaging very close to the floor.
New one will be here tomorrow, picked up the new slave this afternoon.

[1st 5er]

Yesterday afternoon I picked up the new master.
I decided to install the new master first.
I did, and after bleeding the system the symptom of 'on the floor engagement' was still there.
I went to r&r the slave, but decided to do the Kyle bleed first, just in case, and noticed a slight bit of seepage,
not enough to cause a drip but enough to wet around the plunger,
when depressing in the plunger so went ahead and changed it out,
since I had a new one on hand.
Hooked the plumbing up to the new one, Kyle bled it, bolted it onto the bellhousing, and test drove the car.
Result, worked perfectly.

The pedal bracket was indeed cracked, and needed replacing.
The master had been bolted to the left of the mounting tab causing the plunger to move in and out at an angle,
resulting in premature wear and less than 100% functionality.
And finally the used slave cylinder had a very slight leak.

Now that this is sorted out I can get back to working on the a/c.

[Dana R]

Nice writeup, Sherman. I'm hoping I won't have to do this for a while!

[1st 5er]

Thanks.

The original failure that led this whole process was when the over-under spring disintegrated.

Here's the way I did that job, copied from this thread.
http://www.mye28.com/viewtopic.php?p=878993#878993

With the MC body bolted to the bracket and its' push-rod still unattached, raise the pedal as high as you can.
To raise the pedal you must also unbolt and remove the small bracket that holds the cruise control clutch release switch.
Unbolt the broken over-under spring from the mount, and bolt on the new one*.
Be sure the fins on the spring side are perpendicular to the mounting bolt hole so they will sit solidly in the bracket groove.
Now lower the pedal placing the fins in the groove and bolt the MC plunger to it's respective mounting tab*.

* Both the MC and Spring bolt to the right sides of their clutch pedal tabs.



http://www.mye28.com/viewtopic.php?p=878993#878993

[Mab1957]

Yes, right side of pedal bracket.


Thanks for the tips on how to align the over center spring. I did it the hard way last time and will use your process next time.[/img]