Warm rear wheel

[Highnote1]

Replaced everything in rear brakes a few months ago. 74tii. Brembos drums and  shoes from blunt. Pedal is good. 
 

Rear Passenger side still drags no matter what I do. I have adjusters freed up and not contacting shoes at all. Drivers side is fine but passenger is still dragging after a drive. 
 

E cables seem fine..the only thing I’m wondering is if spring is not returning arm all the way open again after using. Cables engage and let go enough to spin wheel by hand but still get warmth! Can those springs get weak but cable still operate ok?
 

Any ideas? I had drums off many times now at this point trying to solve. 

[tech71]

What about the brake cylinders. Did you replace them?

They can corrode/ bind/seize up. Result is a stuck or binding brake on one side

[Mike Self]

Have you checked to see if the emergency brake cable on that side is not moving freely?  Pull the pax drum, and have lovely assistant pull up on the e-brake handle while you observe the cable moving.  They can get stuck in their housings--usually the cable's plastic cover starts to disintegrate and jams up in the guide tube--and not allow the brake to release.

 

Another thought...I just replaced both drums and shoes on my '73, and discovered that even with the adjusters backed all the way off, the drums dragged.  I ended up hand filing the high spots on the shoes--several times--before they would clear the drums.  When you pull the drums, look at the shoes' friction surfaces for high spots, and file accordingly.

 

And...the problem may be a failing rear wheel bearing.  While you have the wheel off the ground and before you remove the drum, rotate the drum and listen/feel for any noise or roughness...that might be a bearing moving into failure mode...

 

mike

[Highnote1]

16 minutes ago, tech71 said:

What about the brake cylinders. Did you replace them?

They can corrode/ bind/seize up. Result is a stuck or binding brake on one side

New cylinders too!

[John76]

Pull the passenger shoes and check the rivet that holds the e-brake lever.

I had a new set of shoes and could not get the passenger side to stop dragging (all new e-cables, brake lines & cylinders) and finally discovered the e-brake lever was sticking and not releasing. Had to pry the rivet a bit and add a drop of lube to get it right.

Also check the upper spring to make sure the hooks are facing out.

Let us know what you find.

 

John

 

[Highnote1]

5 minutes ago, John76 said:

Pull the passenger shoes and check the rivet that holds the e-brake lever.

I had a new set of shoes and could not get the passenger side to stop dragging (all new e-cables, brake lines & cylinders) and finally discovered the e-brake lever was sticking and not releasing. Had to pry the rivet a bit and add a drop of lube to get it right.

Also check the upper spring to make sure the hooks are facing out.

Let us know what you find.

 

John

 

Rivet area is good…did a search and knew to check that as well. My springs are not facing out…seemed like such a b to get that to happen. I don’t see the hook contacting anything else but can go back and do that over again…sandwiching all of that together with spring on the inside seemed pretty hard!

[John76]

4 minutes ago, Highnote1 said:

sandwiching all of that together with spring on the inside seemed pretty hard!

Install the spring properly on both shoes before you slip the ends into the brake cylinder pucks.

Then use clamps to hold the bottoms while you wrestle with the lower "B"-spring.

[halboyles]

37 minutes ago, John76 said:

while you wrestle with the lower "B"-spring.

If you use clamps like @John76 recommends, it is very easy to jack the spring up into the retainer with a floor jack.

[jp5Touring]

43 minutes ago, halboyles said:

If you use clamps like @John76 recommends, it is very easy to jack the spring up into the retainer with a floor jack.

This is the way to go though its a bit sketchy. Works easy with  two people.

We had to do this like three different times after we got everything correct.

Takes like two minutes to get it attached.

 

Not quite as fun as using a spring compressor. 🙂

[Rodolfo Lasparri]

Mine just did the exact same thing, but I had some bad drag after the first run on the pass side. It turned out my new wheel cylinder wasn't working properly. One side was stuck for some reason and after some finagling, I was able to free it up; all good then. I am running the 320i larger drums on my 73 Tii  - so not exactly the same as you.

[rstclark]

Check the Ebrake cables for free movement  The tubes get rusty and snag  I'll bet that's the problem

[Dudeland]

Residual Pressure?  When is the last time you replaced the flex lines?  Could be swollen or blocked. 

 

[Highnote1]

1 hour ago, Dudeland said:

Residual Pressure?  When is the last time you replaced the flex lines?  Could be swollen or blocked. 

 

I have good fluid to the drums on bleeding but have new lines if nothing else fixes it. Will dig back in on Sunday again.