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Jtast17 Samba Member
Joined: November 02, 2004 Posts: 220 Location: Elmira, NY
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Posted: Mon Aug 02, 2010 5:02 pm Post subject: Brake drum drag on rear after new drums, shoes...the works.. |
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Yes...after all is said and done I just replaced everything on the rear due to wear and fatigue...this includes...
-brake backing plates
-both sets of rear shoes of course
-both rear wheel cylinders
-all hardware
-ebrake cables
-replaced p side rear brake hose and metal line from hose to wheel cylinder as well as to rear T junction...
So...I did everything by the book, adjusted the brakes after bleeding and then checked for bleed again. Lastly...did the ebrake.
I got the bus back on all four yesterday and was able to take her out for a test drive today. Needless to say...I don't know whether I did something wrong or its part of the new drum/shoe break in process but I have a significant brake shoe contact on drum noise when coming to a stop. It goes away above 20mph or so...but it just doesn't seem right.
Brought the bus back home...lifted each side. P side wheel turns with the ever so slight amount of drag.... D side, slight bit more but I can turn it with my hand but it will "bind".
Tried backing off the star adjusters which are in great mechanical shape now (followed the bench cleaning/use of anti seize, etc) but that didn't reduce the drag on the d side rear. Backed them off all the way and I lose pedal *and though a bit less "noise"...still have the drag sound).
Anyone have any ideas?
I tried bleeding with a MityVac since I didn't have a spare bay MC cap so I could use it on my pressure bleeder I made for all my other vehicles. I really didn't like the Mity Vac. I may go try and find another bay MC cap so I can just double check the system for the bleed...but I feel like is isn't a problem of not enough pressure...rather...too much almost.
Any ideas? Or is the drag noise normal for new brakes on it (i've never personally experienced that being the case before)
Joe _________________ 1972 VW Westfailia
1966 Corvair Monza
2001 Audi TT 225Q Roadster
2009 VW Tiguan SE |
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nathansnathan Samba Member
Joined: April 14, 2008 Posts: 1671
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Posted: Mon Aug 02, 2010 5:08 pm Post subject: |
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I've read that you should aim for 7 clicks of the parking brake handle to fully engage your parking brake. Mine is about like that, though I think they recently do a bit more, an indication that they need adjustment. To achieve this, you do need to rub a little but not to where it's hard to turn or anything. It starts rubbing on mine pretty far out but I'd have no parking brake at all if I stopped there. |
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Jtast17 Samba Member
Joined: November 02, 2004 Posts: 220 Location: Elmira, NY
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Posted: Mon Aug 02, 2010 5:08 pm Post subject: |
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giving some further thought to this. I had a TERRIBLE time installing the brake shoe retainers on the bus this time around. They really have to be compressed to fit on the bus with the shoes it seems (though they are on). I remember reading that many have omitted them since VW didn't include them on the cars. I'm wondering if the retainers aren't allowing the full return of the shoes...should I remove/omit them from the assembly?
Just a thought.
Joe _________________ 1972 VW Westfailia
1966 Corvair Monza
2001 Audi TT 225Q Roadster
2009 VW Tiguan SE |
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nathansnathan Samba Member
Joined: April 14, 2008 Posts: 1671
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Posted: Mon Aug 02, 2010 5:19 pm Post subject: |
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I know there are 2 rear brake styles in a bay.
Weird in the gallery these both say 69?
you have the same as me, the 2nd one, I think that's early?
I don't know what part is the retainer? |
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nathansnathan Samba Member
Joined: April 14, 2008 Posts: 1671
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Posted: Mon Aug 02, 2010 5:22 pm Post subject: |
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oh, duh the first is the front. Well I know there are 2 styles. I can't find a picture of the other rear.
And now I'm guessing the retainer is the pin/ spring/ cap part on both sides
hmmm... I wouldnt remove those. |
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nathansnathan Samba Member
Joined: April 14, 2008 Posts: 1671
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Posted: Mon Aug 02, 2010 5:25 pm Post subject: |
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here's something:
I think it is this one that a 72 has, see how there is only 1 spring accross the bottom? I wonder if that is why they drag, like to say they kind of ....did drag on the early. |
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VDubTech Samba Member
Joined: December 29, 2002 Posts: 9142 Location: Syracuse, NY
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germansupplyscott Samba Member
Joined: May 22, 2004 Posts: 7093 Location: toronto
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Posted: Mon Aug 02, 2010 5:50 pm Post subject: |
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if you replaced backing plates and not drums i'll bet the grinding noise is from the notch in the drum that the backing plate nests into. remove the drum and diegrind inside the notch. _________________ SL |
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Jtast17 Samba Member
Joined: November 02, 2004 Posts: 220 Location: Elmira, NY
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Posted: Mon Aug 02, 2010 6:12 pm Post subject: |
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started a new thread because its about a different part of the rebuild. Didn't think it was a huge problem. Oh well.
One hose was replaced because both were replaced about 5-6 years ago. The drivers side looked great and was functioning well...the p side had a bad wheel cylinder and there looked to be debris plugging the line on initial bleed...inspection...hence the replacement back to the "T"
Everything was replaced...backing plates, and new drums as well as all the insides.
Joe _________________ 1972 VW Westfailia
1966 Corvair Monza
2001 Audi TT 225Q Roadster
2009 VW Tiguan SE |
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VDubTech Samba Member
Joined: December 29, 2002 Posts: 9142 Location: Syracuse, NY
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Posted: Mon Aug 02, 2010 6:18 pm Post subject: |
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I can't believe someone would do all of that work and not replace both hoses. It makes no difference what it looks like on the outside, what matters is what's inside, and you can't see that. _________________ First Trip in the RustyBus:
http://www.thesamba.com/vw/forum/viewtopic.php?t=279077&highlight=
borninabus wrote: |
a measurement of your rod would be extremely useful. |
notchboy wrote: |
my dad wasnt a belittling cock when he tought me how to wrench on cars. |
EverettB wrote: |
One photo = good for reference.
10 photos = douchebaggery |
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Jtast17 Samba Member
Joined: November 02, 2004 Posts: 220 Location: Elmira, NY
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Posted: Mon Aug 02, 2010 7:04 pm Post subject: |
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Thanks for the help. Seriously? I have done enough brakes to be able to tell if I need to replace the hose. The bus has seen maybe 300 miles in the last few years...the d side had already been replaced. The p side hadn't and neither are part of the problem at this point. Are you guys going to seriously sit here and lecture me on that and thread posting? If so...just personally...save the comments.
I just asked a question. That is all...was looking for help.
Joe _________________ 1972 VW Westfailia
1966 Corvair Monza
2001 Audi TT 225Q Roadster
2009 VW Tiguan SE |
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Desertbusman Samba Member
Joined: June 03, 2005 Posts: 14655 Location: Arizona
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Posted: Mon Aug 02, 2010 7:17 pm Post subject: |
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nathansnathan wrote: |
here's something:
I think it is this one that a 72 has, see how there is only 1 spring accross the bottom? I wonder if that is why they drag, like to say they kind of ....did drag on the early. |
That's what my '71 is. But you are wrong. There is a heavier spring across the top which you arn't seeing. But it's there. I can see the spring end.
You have to have your 3 piece retainer on each shoe. And on the backing plate where the shoe rides on the little bumps must be smoothe and most of us use a bit of lube. Naturally when you adjust the shoes you adjust the front and rear shoe at the same time. But they are independant of each other and no need to do equal clicks. Just adjust them out 'till they contact the drum, a couple hard pushes on the pedal to center them and adjust again. Do it a couple times until they are centered and tight and then back off a couple clicks. If you adjust them out tight with the adjusters it pretty much centers them also.
Your grinding is probably the drum rubbing on the backing plate. Evidently some new drums are apt to do that. _________________ 71 Superbug
71 Westy |
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nathansnathan Samba Member
Joined: April 14, 2008 Posts: 1671
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Posted: Mon Aug 02, 2010 7:19 pm Post subject: |
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See how in the last picture I posted there's a hex bolt holding the parking brake lever on?
That's how mine was too, funny enough. There's supposed to be a flanged dowel thing that is way more fitted. There's a nut on the other side of that, and like mine, when it came loose, it made the lever rub on I think The drum. Maybe yours is the same. |
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nathansnathan Samba Member
Joined: April 14, 2008 Posts: 1671
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Posted: Mon Aug 02, 2010 7:27 pm Post subject: |
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Desertbusman wrote: |
But you are wrong. |
I'm a bit confused about the differences. There may be more than 2 styles. I recall seeing mostly "the other kind" than what I have in the piles I sorted through looking for the right parking brake lever. they are different between the 2 pics. Believe me, I bought the wrong part. I was talking about the spring(s) by the bottom adjustor - in the other style or at least in the other pic, there are 4 spring ends, though they seem to go to 1 spring. Mine, the 72 isn't like that. That being a 69(?) it makes me think I have the late (?) but for some reason I thought "the other style" was the later.
Now that everyone is confused... |
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Desertbusman Samba Member
Joined: June 03, 2005 Posts: 14655 Location: Arizona
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Posted: Mon Aug 02, 2010 7:38 pm Post subject: |
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nathansnathan wrote: |
I'm a bit confused about the differences. Now that everyone is confused... |
No, just you. _________________ 71 Superbug
71 Westy |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Mon Aug 02, 2010 7:41 pm Post subject: |
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were the drums turned? There may be a ridge inside that is rubbing on the new shoes.
What tools did you use? I have been doing this for 35 years and it pays to have the right brake tools to stretch the springs and put on retainers.
The shoes aren't the only thing that rubs. On our driver side when I took it apart the E-brake cable was rubbing on the hub. It had done it so long the cable was worn through almost. Bad PO job.
Is the rubbing even or does it go whoosh ..........................whoosh...................whoosh If so the drum maybe oval shaped if you didn't have it turned.
And if the drag is even then I would suspect as Scott of German Supply suggested, that the backing plate is rubbing on the drum. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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Desertbusman Samba Member
Joined: June 03, 2005 Posts: 14655 Location: Arizona
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Posted: Mon Aug 02, 2010 7:44 pm Post subject: |
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Jtast17 wrote: |
Everything was replaced...backing plates, and new drums as well as all the insides.
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_________________ 71 Superbug
71 Westy |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Mon Aug 02, 2010 7:46 pm Post subject: |
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Desertbusman wrote: |
Jtast17 wrote: |
Everything was replaced...backing plates, and new drums as well as all the insides.
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they say the first thing that goes is/are the eyes................. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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Jtast17 Samba Member
Joined: November 02, 2004 Posts: 220 Location: Elmira, NY
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Posted: Mon Aug 02, 2010 8:33 pm Post subject: |
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my setup is exactly like this one that is pictured...
I have seen the "flanged" bolts missing, etc. before as well. However, I've got all the stock hardware in mine, etc. The entire hydraulic line assembly was replaced about 5-6 years ago...like i said before..hence the non-replacement of the drivers side rubber line...there was no issue there. P side was for preventative purposes due to the failed wheel cylinder and worrying about some debris being back through the line...non issue.
Quote: |
were the drums turned? There may be a ridge inside that is rubbing on the new shoes.
What tools did you use? I have been doing this for 35 years and it pays to have the right brake tools to stretch the springs and put on retainers.
The shoes aren't the only thing that rubs. On our driver side when I took it apart the E-brake cable was rubbing on the hub. It had done it so long the cable was worn through almost. Bad PO job.
Is the rubbing even or does it go whoosh ..........................whoosh...................whoosh If so the drum maybe oval shaped if you didn't have it turned.
And if the drag is even then I would suspect as Scott of German Supply suggested, that the backing plate is rubbing on the drum. |
a few other things are leading me down this path as well. After taking it out for the initial run (and I should have posted it initially) I did a check of the brake/wheels just by "the touch" to see if the "rub" was due to dragging of the brake shoes seriously inside the drum. If the brakes were dragging to that extent and for the 20min duration that I was gone...those drums should have been pretty damn hot. They were only warm to the touch which really brings me back to a interference/machining issue with the backing plate vs. the new drum. The backing plates are OEM replacements, VW Brazil I believe right from Bus Depot...the drums are from Bus Depot as well and are Italian units that had a great surface to start with...and were new...should they be turned? I've never had to do that with new drums before.
I have all the brake tools for compressing calipers, brake spring/retainer pliers, etc. Didn't have an issue there. I think it was just the length of the retainer posts that gave me fits. Plus, those brake spring pliers I haven't aren't super fancy units and the "retainer" tool on the end of them is not quite small enough for the vw spring retainer caps. It worked out though...they went on....
In thinking about the "rubbing" as you describe it. On the passenger side...its only very slight...not worried there at all. On the d side it is intermitent as you mentioned .......whoosh......whoosh....and its in the same place. I am willing to bet it is indeed the backing plate making contact with the drum.
brakes were great on that run though...sound was just really annoying! maybe I'm going to have to do some more investigating and look at it again tomorrow. Might have to let the backing plate/drum (if its making contact) just "machine" itself out or do as Scott mentioned...though, this is with a new drum...not a used set. Do want to check on having those drums turned though and if they need to be from "new".
I appreciate the focus and help. Gives me more ideas to kick around.
Joe _________________ 1972 VW Westfailia
1966 Corvair Monza
2001 Audi TT 225Q Roadster
2009 VW Tiguan SE |
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kreemoweet Samba Member
Joined: March 13, 2008 Posts: 3898 Location: Seattle, WA
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Posted: Mon Aug 02, 2010 9:14 pm Post subject: |
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If the shoe retaining pins are too short (which seems likely from your
description), the shoes will be clamped to the backing plate with excessive
force. The brake cylinder pistons will be able to move them, but the
return springs may not be able to retract them sufficiently when you release
the brakes. This could cause (possibly intermittant) scraping noises. There
are several different lengths of retaining pins. I would suggest you make
sure you have the correct length. _________________ '67 bug: seized by the authorities
'68 bug: seized by the authorities
'71 kombi: not yet seized by the authorities
Stop dead photo links! Post your photos to The Samba Gallery! |
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