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Home » Public Forums » GMCnet » drum brake rookie (mistake)
drum brake rookie (mistake) [message #304476] Thu, 28 July 2016 21:58 Go to next message
pzerkel is currently offline  pzerkel   United States
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Registered: September 2007
Location: Salisbury, IL
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Senior Member
Today was the first time I ever attempted any drum brake maintenance DIY (on any vehicle) . I made some mistakes, now what do I need to fix them.

I ended up with two extra parts. http://www.zerkelhome.com/drum-extra.JPG

I was smart enough to take a picture before I began. http://www.zerkelhome.com/drum-before.JPG

And after is here: http://www.zerkelhome.com/drum-after.JPG

Looking closely at the after picture and Using the diagram on page 5-4 of X-7725 I believe I am missing item 10 (pivot) and also item 13 (override spring).

This is the passenger side rearmost wheel.

I was working outside and was interrupted by a popup thunderstorm, then it was getting dark, and I got in a hurry. I put the drum back on for now, but realize there are issues. I will look for the missing pivot part tomorrow in the daylight. If I do not find it; first question is this a commonly available part, or something specific to the GMC motorhome brakes?

Next question; The way it is, is it safe to drive it about 8 miles to the shop that I have trusted in the past to inspect/maintain the rear brakes on this coach? FWIW, I still absolutely trust that local shop, but just wanted to try this on my own.

My motivation for diving in was; the last time I tried to bleed the brakes (which I have done successfully several times in the past), I broke a bleeder valve on this wheel cylinder. I was replacing this wheel cylinder due to that. I did get the new wheel cylinder in, but as you can see from the photos, I have issues.

I am not sure how to proceed.




Paul Zerkel
'78 Eleganza II
Salisbury IL (near Springfield)
Re: drum brake rookie (mistake) [message #304477 is a reply to message #304476] Thu, 28 July 2016 22:28 Go to previous messageGo to next message
Adrien G. is currently offline  Adrien G.   United States
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Registered: May 2008
Location: Burns Flat, OK 73624
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Well, the washer with the collar goes under the shoe retainer spring where the adjusting lever pivots.
Without it the adjuster will not automatically adjust the shoe wear.
The other item I can't completely see what it is. It look like a plug or ?

The rest of the assembly look OK.
I don't see any problem driving it that short distance with that pivot washer out.
You will have to manually adjust the brake shoes or you may not have much brakes to stop.




Adrien & Jenny Genesoto 75 Glenbrook (26-3) Mods LS3.70 FD / Reaction Sys / 80mm Front&Intermidiate / Hydroboost / 16" Tires / Frame Rebuild / Interior Rebuild Yuba City,Ca. Text 530-nine-3-three-3-nine-nine-6
Re: drum brake rookie (mistake) [message #304484 is a reply to message #304477] Thu, 28 July 2016 23:44 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
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Registered: January 2004
Location: Hebron, Indiana
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If you still have the wheel off it will only take a minute to put that collar under the left side hold down spring. I also can not tell from the picture what the other item is.

Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Re: drum brake rookie (mistake) [message #304487 is a reply to message #304484] Fri, 29 July 2016 02:16 Go to previous messageGo to next message
Bullitthead is currently offline  Bullitthead   United States
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The other part looks like the rubber cap that goes on the bleeder to keep dirt out.

Terry Kelpien ASE Master Technician 73 Glacier 260 Smithfield, Va.
Re: [GMCnet] drum brake rookie (mistake) [message #304488 is a reply to message #304487] Fri, 29 July 2016 03:39 Go to previous messageGo to next message
G?Rs66 is currently offline  G?Rs66   United States
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Registered: May 2016
Location: Wautoma, Wi.
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Ken is right I have done brakes all my life just pop the retainer off put
little tip in first put the spring back on and instal drum then adjust your
brakes. When adjusting make sure you are turning the wheel when you start
feeling drag on the brake stop. After you put the wheel back on drive
backwords and step on the brake a few times and wil set your final
adjustment
On Jul 29, 2016 2:17 AM, "Terry" wrote:
>
> The other part looks like the rubber cap that goes on the bleeder to keep
dirt out.
> --
> Terry Kelpien
>
> ASE Master Technician
>
> 73 Glacier 260
>
> Smithfield, Va.
>
>
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1978 Transmode 1966 GTO{frame off restor} Wautoma, Wi (About 35 miles west of Oshkosh, Wi) Gene Don't Do Facebook but Ronny does
Re: drum brake rookie (mistake) [message #304496 is a reply to message #304476] Fri, 29 July 2016 08:33 Go to previous message
Matt Colie is currently offline  Matt Colie   United States
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Registered: March 2007
Location: S.E. Michigan
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Senior Member
Paul,

Now that you have broken one (of a possible 6) bleed screws, please let me pass along some other advice that those of us that live where rust happens have learned.

Never Ever forget the rubber caps on the bleed screws....

Get some teflon tape and wrap each screw 1-1/2~2 turns in the thread direction. This has two functions and a couple of benefits.
First is that it prevents brake fluid from going into the threads while you are bleeding the brakes. Brake fluid is highly hydroscopic and went it absorbs water, it seems to promote corrosion.
Second is that prevents environmental water from coming into the threads from outside.

A third is that it seems to make bleeding go better as you get to a clear stream more easily.

I used to do this with a teflon pipe thread dope, and it worked much better than nothing. Then Chuck Boyd said he used the tape and I tried that and it works better.

Even if that is the only bleeder that you broke this time, seriously consider taking the time and mess to wrap all that others before you leave the job.

Matt


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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