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Patrick

I took off my drums to replace a broken flat spring metal that locks the star adjusters and removed the shoes and stuff to clean out the inside. I put the drums back in and am pretty sure i put everything back on right(star adjusters all the way in, centered the brakeshoes as best i could and stomped on my brakes a couple of times to re-center the shoes). Problem is that the break lining is binding my drum so tight that even with my wheel attached i have a very difficult time turning the wheel! I then removed the drum and pushed it back in about 3/4 way and turned the drum and checked around to see which parts of the brake lining was hitting the drum and saw that most of it was hitting (i barely got a newspaper strip between the lining and the drum and couldnt get the paper strip in about the last 1/4 of the LENGTH of the brake lining). The brakeshoe isnt bent and the brake lining is ok and the wheel cylinder pistons have gone in as much as they can, i even temporarily disconnected the emergency brake cable. It just seems plain to me that the shoes are just too close to the drum. I seem to remember other mechanics in the past telling me that the lining seemed just too close to the drum, so i thought i`d do it myself. FYI, i`m not even sure if my brake shoes and associated brake hardware are porsche or aftermarket porsche, might be from the VW beetle. I unfortunately have no other 924 part to compare with as 924`s over here are very rare and people wont open up their brakes for me and our only porsche dealer doesnt carry 924 parts i can examine. If i dont figure this problem out, i`m thinking about GRINDING away maybe 3mm of metal from the ends of the brakeshoe that contacts the wheel cylinder slots and the star adjuster slots. Anybody have any thoughts on this? Any dangers with this? Your help/comments are appreciated. THANKS!

moliver · Joined: 17 Dec 2002 Posts: 59

Compare the old and new brake shoes, do they match? Do you have the right brake shoes?
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87-924s

Patrick · Posted: Tue Dec 11, 2007 10:43 pm Post subject:

RC · Joined: 25 Mar 2007 Posts: 2637 Location: Australia

Had a good BRAKE SHOP get me as set of i think VW? (no idea what) cheaper new than rebonding. Bit late to ask around now.

If theres only about a paper thickness (0.1mm) difference I would try sanding the face lightly, starting at the ends, using a block to maintain squareness. If it needs more than a light sand you have oversize shoes or some other problem. If you need 3mm on each pressure point face to be removed you DO have a problem with INCORRECT shoes or bonding. That equates to about 4mm in diameter. Even 1mnm per face = over 1mm excess dia. Personally theres no way I would do what you suggest on MY car but its your car, your life and your decision.

Roger

Patrick · Posted: Tue Dec 11, 2007 11:27 pm Post subject:

DOCO · Posted: Wed Dec 12, 2007 12:24 am Post subject:

hi did you have the drums machined?if not that is a must,sometimes the drums will go out of round,and with new shoes put on they can just be touching, just to close to one part of the drum.start out with drums that have been turned true.Doc o

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Doco "where am i going and why am i in this handbasket"author unknown
79 924 N/A "Webster"
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"WEBB STR"

Buwani 931 · Joined: 31 May 2004 Posts: 308 Location: Napa California

I am trying to understand the timeline here.

Patrick · Posted: Wed Dec 12, 2007 1:42 pm Post subject:

Sorry for the confusion.I had my drums REFACED and my brakeshoes RELINED about 1 year ago.My drum fit was never this TIGHT, it only got tight after i remove the drums bout 2 weeks ago. About a couple a weeks back i decided to open up my drums to replace one of the flat spring metal clips by the star adjuster and to clean out the insides. Initially i kept the wheels attached to the drums just to make it easy to remove or return the drums. I centered the shoes as best i could(w/star adjusters turned in all the way and w/wheel cylinder pistons pushed in as far as it would go via the upper return spring of course), stomped on the brake pedal a few times to hopefully better re-center the brakeshoes. Then i turn the wheel a couple of times w/difficulty. I then repeated the whole procedure w/the wheel-drum assembly an x number of times, but still no luck...

So i then decided to REMOVE the wheels and work w/the drum alone. I`ve tried pushing the drum in and only manage to cover about 1/2(NOT 3/4 as i mentioned earlier) of the WIDTH of the brake lining(even after turning the drum around quite easily IN THIS POSITION) a few times). And this is where i slip in the small newspaper strip between the drum and the lining as a feeler gauge starting from one end(closest to the wheel cylinder end) of the LENGTH of the lining and dragging the paper till the other end(closest to the star adjuster end). I did this on both shoes and discovered that the paper slips ok just about 3/4 way of the LENGTH of the lining starting from the end closest to the wheel cylinder and refuses to fit the last 1/4 of the length of the lining closest to the star adjuster end. I hope this makes my explanation clearer. thanks!

Buwani 931 · Joined: 31 May 2004 Posts: 308 Location: Napa California

I sure would not go grinding anything as things had to fit before you took it apart. Return spring sprung or the pressure rod not sitting down in the groove perhaps? The shoe fitting in the grooves at the cylinder and adjuster correctly?

Shawn
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1980 931
That's thirty minutes away. I'll be there in ten.

RC · Joined: 25 Mar 2007 Posts: 2637 Location: Australia

Well that clarifies things substantially. I thought you recently had the shoes relined. So in other words you pulled the drums off, screwed around with it and now it wont go back on.

So if you are sure that the adjuster is at MINIMUM, try undoing the bleed screw 1/2 a turn or so and let any excess pressure bleed out. Now will the pistons (and shoes) go in a bit more? And the drums fit on? Then DONT pump the pedal and slowly wind the adjusters out.

Roger

Patrick · Posted: Wed Dec 12, 2007 7:56 pm Post subject:

I havent had a chance to do my brakes today and will do it tomorrow. I will open up my bleeder screw a bit to push in the wheel cylinder pistons more as suggested, and will check again how things fit. Oh, got a question about the pressure rod(the flat metal between the 2 brakeshoes), One end has only ONE groove to fit the forward brakeshoe, and the other end (to fit the brakeshoe w/ the e-brake mechanism) has TWO grooves, SHORTER groove goes to the e-brake lever and LONGER groove goes to the brakeshoe, right? Thanks again!

RC · Joined: 25 Mar 2007 Posts: 2637 Location: Australia

Looking at figure 9.5 in haynes which is same as factory manual, there is one wide slot and it appears the deeper side goes on the E brake lever. Maybe that is your problem then? It is good practice to do one side at a time so you can refer to the other side to see how things fit.

Roger

Patrick · Posted: Sat Dec 15, 2007 8:44 pm Post subject: