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Terry Kay Banned
Joined: June 22, 2003 Posts: 13331
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Posted: Fri Jul 31, 2015 2:30 pm Post subject: |
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What was pretty amusing, & set me abaft in this conversation was most folks weren't aware that the shoes actually moved with their application beyond just in and out.
And that then primarily wearing away at the cylinder upper sides was an indication of them not being able to float with the drums.
Item's overlooked and not considered.
Taken for granted I guess.
Thanks for the shim offering--
The brakes in my coach are just ducky, and both ends are all new & work fine.
I have to really get into the mood to yank them just for the heck of it & pop shims in there.
Might be a good idea though to paint the faces of the shoes to see how they ride.
You guy's would take a dump if they were wearing out on the bottoms faster.
Maybe another interesting subject brought up by yours truly.
Oh boy _________________ T.K.
Last edited by Terry Kay on Sun Aug 02, 2015 7:35 am; edited 1 time in total |
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tlbranth Samba Member
Joined: May 24, 2014 Posts: 209 Location: Carnation, Wa
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Posted: Fri Jul 31, 2015 2:37 pm Post subject: |
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I just put on new shoes. The fronts touch mostly at the top but show mild contact further down. The rears touch only the top 1/3. By front and rear, I'm referring to front and rear shoes on rear brakes. I investigated because my pedal was low but the brakes are firm. I figure the adjusters are not working (imagine that). I'm going to shim the thing - assuming I can get out the one thingy that's stuck in its socket. It's pretty obvious to me that the brakes will work better because of increased contact area and a greater mechanical advantage. Too bad these things don't adjust the bottom of the shoe.....but then they really don't seem to adjust the top either. _________________ Terry
1991 Westfailure. 2004 Forester 2.5 engine. 4speed Standard transmission. |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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Posted: Fri Jul 31, 2015 3:55 pm Post subject: |
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tlbranth wrote: |
I just put on new shoes. The fronts touch mostly at the top but show mild contact further down. The rears touch only the top 1/3. By front and rear, I'm referring to front and rear shoes on rear brakes. I investigated because my pedal was low but the brakes are firm. I figure the adjusters are not working (imagine that). I'm going to shim the thing - assuming I can get out the one thingy that's stuck in its socket. It's pretty obvious to me that the brakes will work better because of increased contact area and a greater mechanical advantage. Too bad these things don't adjust the bottom of the shoe.....but then they really don't seem to adjust the top either. |
If you don't think that they do adjust the bottom of the shoe, then you haven't yet grasped how they actually work.....
If your drum setup is not adjusting the bottom of your shoes, your brake assembly is rusty, seized and not functioning properly.
The shims will help.... For awhile ......... but the problem will still be there.
Dave _________________ Stop Dead Photo Links how to post photos
Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473
Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537
Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert |
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Vanagon Nut Samba Member
Joined: February 08, 2008 Posts: 10347 Location: Sunshine Coast B.C.
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Posted: Fri Jul 31, 2015 4:57 pm Post subject: |
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Terry Kay wrote: |
What was pretty amusing, & set me abaft in this conversation was most folks weren't aware that the shoes actually moved with their application beyond just in and out.
And that them primarily wearing away at the cylinder upper sides was an indication of them not being able to float with the drums.
Item's overlooked and not considered.
Taken for granted I guess.
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Terry. re: floating. I'm certain I'm not the only one that simply did not know of this aspect. There are so many systems on a Westy (Vanagon) to learn about. That's a lot of details to encompass as I'm sure you know. And by no means do I think for one minute that I've got them all covered!
It's easy to take the rear brakes for granted. In a way, I'm sure I did at one point.
Neil. _________________ 1981 Westy DIY 15º ABA
1988 West DIY 50º ABA
VE7TBN |
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tlbranth Samba Member
Joined: May 24, 2014 Posts: 209 Location: Carnation, Wa
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Posted: Fri Jul 31, 2015 5:25 pm Post subject: |
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The rear brake is a copy of every single leading shoe brake used on just about every car in the country back when I started working on them in the early 60's. I'm familiar with the float feature. _________________ Terry
1991 Westfailure. 2004 Forester 2.5 engine. 4speed Standard transmission. |
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Terry Kay Banned
Joined: June 22, 2003 Posts: 13331
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Posted: Fri Jul 31, 2015 6:32 pm Post subject: |
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The basis for my interjecting the floating non-fixed theory here was it seemed that most folks in the mix were not aware that the brakes were not supposed to be fixed to the bottom of the backing plate, nor are the pivots supposed to be frozen in their holders.
This is / was reason I tried to bring this to everyone who was talking about shims and was involved attention, and this in fact was the main reason for uneven shoe wear.
I'm sure a few folks may have known this, but it was a miniscule few.
It was an FYI by TK for the unknowing, and uninformed.
Thats all. _________________ T.K. |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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tlbranth Samba Member
Joined: May 24, 2014 Posts: 209 Location: Carnation, Wa
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Posted: Fri Jul 31, 2015 6:46 pm Post subject: |
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Dave, I believe the underlying problem is poor design. But at 70 years of age I can get zero distance in a pissing contest so let's just call you the winner and leave it at that. _________________ Terry
1991 Westfailure. 2004 Forester 2.5 engine. 4speed Standard transmission. |
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Terry Kay Banned
Joined: June 22, 2003 Posts: 13331
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Posted: Fri Jul 31, 2015 7:13 pm Post subject: |
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I was wondering;
One would assume that after having a hell of a time getting the lower pivots out of their holder's to add shims, wouldn't one think that something was wrong with this feature?
My second thought is, who came up with this ( yes Very Ruby) "fix".
Somebody had to be exersizing the grey matter to not fix the real issue, but adding another dimension to the lower pivot angle of attack.
I'll be honest, it had me scratching my head for awhile.
Then the lightbulb lit.
Ah-Ha! _________________ T.K. |
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crazyvwvanman Samba Member
Joined: January 28, 2008 Posts: 9895 Location: Orbiting San Diego
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Terry Kay Banned
Joined: June 22, 2003 Posts: 13331
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Posted: Fri Jul 31, 2015 8:49 pm Post subject: |
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And I think Dennis Hayes was a pretty smart guy, but again, I didn't see him mention one item of being sure, that all of the brake hardware was free and operational in the rear brake bulding process.
Again, if the shoes would be able to float on the drum freely and allowed to make full contact on their own when they are applied that silly millimeter wouldn't make one iota of a difference--
The lower portion of the shoe on the pivots are made to ramp out when the brakes are applied.
If they are rusted up in the pivots,if the pivots are rusted up, the operating idea & theory is defunct.
This is a pretty simple mechanical process, and it all has to be working right.
All of the brake hardware has to up to snuff--contact points on the backing plate lubed to be slick to the shoes.
If the lower pivot or shoes are rust up in that lower holder it isn't going to work right--and the top portion of the shoe is going to be doing most of the work.
Plain & simple.
The idea of keeping everything back there clean, lubed & free for some reason seems like an impossibility here.
Add shims, and forget the rest of it --
Huh-- _________________ T.K. |
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shadetreetim Samba Member
Joined: January 10, 2011 Posts: 1994 Location: Riverside, California
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Posted: Fri Jul 31, 2015 9:21 pm Post subject: |
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Terry Kay wrote: |
And I think Dennis Hayes was a pretty smart guy, but again, I didn't see him mention one item of being sure, that all of the brake hardware was free and operational in the rear brake bulding process.
Again, if the shoes would be able to float on the drum freely and allowed to make full contact on their own when they are applied that silly millimeter wouldn't make one iota of a difference--
The lower portion of the shoe on the pivots are made to ramp out when the brakes are applied.
If they are rusted up in the pivots,if the pivots are rusted up, the operating idea & theory is defunct.
This is a pretty simple mechanical process, and it all has to be working right.
All of the brake hardware has to up to snuff--contact points on the backing plate lubed to be slick to the shoes.
If the lower pivot or shoes are rust up in that lower holder it isn't going to work right--and the top portion of the shoe is going to be doing most of the work.
Plain & simple.
The idea of keeping everything back there clean, lubed & free for some reason seems like an impossibility here.
Add shims, and forget the rest of it --
Huh-- |
What makes you think that the maintenance wasn't done? Adding shims isn't an either/or solution. In my case the hardware was cleaned and lubed and working as it should, then the shims were added. The shims do not replace maintenance. Outrageous assumptions don't further your argument. _________________ Tim Potts
Doing my best every time I drive it to dispel the myth these Vanagons have to be slow!
'89 Vanagon Bluestar/Country Homes 1.8T & .77 4th
'74 Jeep CJ5 |
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Terry Kay Banned
Joined: June 22, 2003 Posts: 13331
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Posted: Sat Aug 01, 2015 6:55 am Post subject: |
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To further the argument, the Fred Sanford fix was that the shims retarded premature shoe wear on the top of the shoes, and to cause them to wear even.
I don't know who made that ridiculous statement, but you may roll back through all of these enlightening posts and find that BS info Tim if you'd like.
I'm busy. _________________ T.K. |
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tlbranth Samba Member
Joined: May 24, 2014 Posts: 209 Location: Carnation, Wa
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Posted: Sat Aug 01, 2015 9:40 am Post subject: |
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TK - after putting some thought to it, I think your description is correct regarding the floating shoes. If allowed to move freely, the front shoe will adjust itself when the vehicle is moving forward and the rear shoe will adjust itself when moving backward. In the old days, the front wheels had double leading shoes so that both shoes adjusted moving forward. The rear brakes were single leading shoe so that you had something going for you in reverse. I would say that when the vehicle is not moving, neither shoe will adjust itself optimally.
Apparently for the past 50 years I mentally glossed over how this thing actually worked. I've never lubed any of these parts and can't see how you could safely lube much inside the drum area without risking lube on the friction surface. Would you be willing to enlighten? _________________ Terry
1991 Westfailure. 2004 Forester 2.5 engine. 4speed Standard transmission. |
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djkeev Samba Moderator
Joined: September 30, 2007 Posts: 32433 Location: Reading Pennsylvania
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Terry Kay Banned
Joined: June 22, 2003 Posts: 13331
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Posted: Sat Aug 01, 2015 10:01 am Post subject: |
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I would use ( and do ) HD red Sticky Grease.
It's high temp, high pressure , low washout.
Now some guys like using the gold, silver anti seize.
The problem with that stuff is I always have found it dried up after awhile, and like some sort of caulking--not having any lubricity after it's been wherever you put it in time.
Ever go into a can of antiseize that's been open for awhile since the last time you used it?
I've always found that I have to mix some oil in it and stir well to get it to be brushable again--and this is just sitting in the can--it's not hard--but non-brushable--kinda like half set up caulking.
But your on the right page with the floating , sliding shoes.
And this is exactly how they are supposed to work to stay centered in the drums, making full contact.
If them pins on the bottom are skanky and rusted up, or the shoes are rusted up in them pins--No way Jose, are they going to work as planned, and this is exactly why the tops of the shoes go away first--the shoes aren't doing the float your boat mambo any longer--they're stuck.
Glad this came back to you, it's pretty simple, and crazy operation process, but it works when all dialed in. _________________ T.K.
Last edited by Terry Kay on Sat Aug 01, 2015 10:02 am; edited 1 time in total |
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tlbranth Samba Member
Joined: May 24, 2014 Posts: 209 Location: Carnation, Wa
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Posted: Sat Aug 01, 2015 10:01 am Post subject: |
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Dave - I'll give it a try. Thanks _________________ Terry
1991 Westfailure. 2004 Forester 2.5 engine. 4speed Standard transmission. |
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Terry Kay Banned
Joined: June 22, 2003 Posts: 13331
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Posted: Sat Aug 01, 2015 10:26 am Post subject: |
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And--
As you brought up Terry, the rear shoes wouldn't self adjust if they didn't rock with the brake application.
The "other" shim fix may limit the shoe travel.
Just thinking. _________________ T.K. |
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crazyvwvanman Samba Member
Joined: January 28, 2008 Posts: 9895 Location: Orbiting San Diego
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Posted: Sat Aug 01, 2015 10:40 am Post subject: |
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Again, maybe this photo will clear up some of the smoke screen. The intent of the shims under the pivot pins is to push the bottom ends of the shoes closer to the drum so more of the lower lining area will contact the drum area and not just the top of the shoe. Earlier VW buses with very similar rear brake geometry put threaded pivot pins down there so the length of the pins could be increased as needed. Clearly the length of the pivot pin matters and changing it can have a positive effect or the VW factory must have been nuts to base the periodic adjustment of the brakes on intentionally changing that length over time. Vanagons got a self adjusting mechanism instead but the underlying geometry of the basic brake function remained the same.
Same drum diameter, same lining dimensions, same wheel cylinders, same lower pivot pin angle.
Mark |
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?Waldo? Samba Member
Joined: February 22, 2006 Posts: 9752 Location: Where?
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Posted: Sat Aug 01, 2015 11:36 am Post subject: |
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Mark, IMO, your input is among the most valuable and most accurate of anyone on this forum. That said, I believe you may be looking at this incorrectly. The wheel cylinder will push the top of the shoe outward. As soon as the top of the shoe starts to contact the drum, the shoe will rotate along the drum toward the bottom pivot. Because the bottom of the shoe is free to float in the pivot slot, it is not the position of the pivot, but rather the contact angle between the bottom of the shoe and the pivot that will determine the amount of that force that is transferred outward into the drum. Shimming the pivot will not 'move the bottom of the shoe toward the drum'. It will just change the amount of protrusion of the slave cylinder pistons when full force is applied. I do see how shimming the pivot will change the angle of engagement ever so slightly, though. The difference between the bus and vanagon designs just shows that the brake shoe adjustment can occur at either the top or the bottom of the shoe but adjusting both is an unnecessary redundancy.
Last edited by ?Waldo? on Sat Aug 01, 2015 4:40 pm; edited 1 time in total |
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