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Nicholas D Samba Member
Joined: November 06, 2012 Posts: 225 Location: Charleston, SC
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Posted: Fri Jun 25, 2021 3:05 pm Post subject: Brake servo? |
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Hello all, I'm having a sudden issue with the brakes on my 71 westfalia and after searching here and looking under my bus I'm just looking for some confirmation (possibly) about my suspicion. The brakes were working just fine when pretty much all of the sudden the pedal became much harder to push. The brakes still work but definitely require a lot more pedal pressure.
When I apply the brakes it doesn't pull on way or the other but just takes longer to slow down. When I removed the vacuum hose to the servo to make sure the check valve on that line was holding pressure a good amount of brake fluid leaked out of the line. There is definitely still vacuum on the other end of the line.
Does this sound like the servo may have failed, or a possible seal on the master cylinder? Brake work is definitely new to me so any advice would be appreciated. |
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aeromech Samba Member
Joined: January 24, 2006 Posts: 16970 Location: San Diego, California
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Posted: Fri Jun 25, 2021 3:28 pm Post subject: Re: Brake servo? |
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Sounds like you need to get your booster rebuilt. Much better than buying new Chinese. You might also get a $70 Brazilian master cylinder while you’re at it. Don’t forget to order two bungs and two condoms _________________ Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound |
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kreemoweet Samba Member
Joined: March 13, 2008 Posts: 3899 Location: Seattle, WA
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Posted: Fri Jun 25, 2021 4:28 pm Post subject: Re: Brake servo? |
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Nicholas D wrote: |
Does this sound like the servo may have failed, or a possible seal on the master cylinder? |
Perhaps both. Significant fluid in the servo means the master cylinder seals have failed. The servo should still work with
some brake fluid in it, but if you have the vacuum connection in the usual upper left position, and you have fluid in
the vacuum hose, that means your servo is just about full of brake fluid, and that's a LOT. How's the level in your
refill reservoir? Maybe the servo will work again if you take it out and clean it, but maybe not. _________________ '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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aeromech Samba Member
Joined: January 24, 2006 Posts: 16970 Location: San Diego, California
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Posted: Fri Jun 25, 2021 4:38 pm Post subject: Re: Brake servo? |
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Good point. Brake fluid is water soluble so you could wash it out with soap and water. Then be sure to get all the water out before continuing _________________ Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound |
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Nicholas D Samba Member
Joined: November 06, 2012 Posts: 225 Location: Charleston, SC
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Posted: Sat Jun 26, 2021 7:32 am Post subject: Re: Brake servo? |
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Thanks for the advice, I'll get it off and see if cleaning it helps. I'll also see if I can find any damaged seals in the master. The current servo has this sticker on it which makes me think it's not the original and therefore maybe a lesser quality aftermarket one? That being said, if cleaning it doesn't help would it still be worth sending out for rebuild? I'm all for doing that rather than putting a new one on after reading about potential fitment issues, quality, etc. but if it's not the original would it be worth doing?
There might be a part number on it but it's pretty hard to decipher. Thanks again!
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kreemoweet Samba Member
Joined: March 13, 2008 Posts: 3899 Location: Seattle, WA
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aeromech Samba Member
Joined: January 24, 2006 Posts: 16970 Location: San Diego, California
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Posted: Sat Jun 26, 2021 8:02 am Post subject: Re: Brake servo? |
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Looks original. I wouldn’t waste any time. Order a new Brazilian MC and get your booster into a rebuilder. _________________ Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound |
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vwmerckx Samba Member
Joined: August 12, 2012 Posts: 195 Location: Phoenix, AZ
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Posted: Sat Jun 26, 2021 8:05 am Post subject: Re: Brake servo? |
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Original Brake Servo from my 71 Tintop. There is a weep hole at the bottom of the Master Brake Cylinder. Brake Fluid was weeping from the weep hole. Lowering level of brake fluid in the reservoir was first indication there was a leak somewhere. I was able to soak out all the brake fluid in the servo (left in place on The Bus) with rags, replaced the Master Brake Cylinder (including O-ring between the servo and brake cylinder) with an NOS purchased off of The Samba. and all is working great four years on since the "repair".
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aeromech Samba Member
Joined: January 24, 2006 Posts: 16970 Location: San Diego, California
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Posted: Sat Jun 26, 2021 12:47 pm Post subject: Re: Brake servo? |
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https://www.busdepot.com/211611021aabr $69.95
https://www.busdepot.com/211611817a (2 each) $3.25
https://www.busdepot.com/211611833c (2 each) $2.49
https://www.busdepot.com/113945515g (2 each) $7.95 _________________ Lead Mechanic: San Diego Air and Space Museum
Licensed Airframe and Powerplant Mechanic
Licensed Pilot (Single engine Land)
Boeing 727,737-200-300-400,757,767
Airbus A319,320,321
DC9/MD80
BAe146
Fokker F28/F100
VW type 1 1962,63,65,69,72
VW Type 2 1971 (3 ea.) 1978, 1969
VW Jetta
VW Passat
Capable of leaping tall buildings in a single bound |
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Nicholas D Samba Member
Joined: November 06, 2012 Posts: 225 Location: Charleston, SC
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Posted: Sat Jun 26, 2021 1:42 pm Post subject: Re: Brake servo? |
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This is great, thanks so much! It definitely happened shortly after I topped off the reservoir so perhaps I exacerbated an existing problem. Either way, I'll clean it at least and rebuilt if needed. I think I remember from a search that someone mentioned a reputable servo rebuilder, but if anyone knows offhand it'd be much appreciated. Thanks again! |
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vwmerckx Samba Member
Joined: August 12, 2012 Posts: 195 Location: Phoenix, AZ
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Posted: Sat Jun 26, 2021 2:44 pm Post subject: Re: Brake servo? |
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As Kreemoweet suggested....my servo worked again after I removed all the brake fluid...and it really was not the servo, but the MBC which allowed brake fluid to migrate into the servo. In any case, you may want to consider soaking the bolts/nuts on your servo/MBC as they look pretty rusted. The NOS MBC I purchased off of The Samba came complete with both switches, reservoir grommets and o-ring. My MBC was the original from 1971 which I had rebuilt with OG rebuild kit some 25+ years ago or so. Your MBC looks after market....so presumably would fail earlier?? |
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Nicholas D Samba Member
Joined: November 06, 2012 Posts: 225 Location: Charleston, SC
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Posted: Wed Jul 21, 2021 12:29 pm Post subject: Re: Brake servo? |
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Quick question - I have everything off or loose with the exception of the reservoir on top of the MC. I'm having a hard time working the line from the top reservoir off of it and wondering how the grommets attach it to the actual master? Can I just work the reservoir off gently? Screwdriver indicates the area I'm talking about. Thanks!
Based on the part description it looks like it can just be worked off, guess I just need a little confirmation before I start pulling.
_________________ 71 Westfalia
73 Beetle |
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Abscate Samba Member
Joined: October 05, 2014 Posts: 22668 Location: NYC/Upstate/ROW
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Posted: Wed Jul 21, 2021 12:39 pm Post subject: Re: Brake servo? |
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They pop off but use a wood implement that won’t gouge or puncture the brake reservoir. Steady pressure upwards to pop it out _________________ .ssS! |
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Nicholas D Samba Member
Joined: November 06, 2012 Posts: 225 Location: Charleston, SC
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Posted: Wed Jul 21, 2021 2:21 pm Post subject: Re: Brake servo? |
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Thanks for the quick reply. I was able to get the hose off so at least I can work those off on the bench now! Appreciate the wooden implement suggestion as well. _________________ 71 Westfalia
73 Beetle |
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Nicholas D Samba Member
Joined: November 06, 2012 Posts: 225 Location: Charleston, SC
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Posted: Fri Aug 06, 2021 6:01 pm Post subject: Re: Brake servo? |
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Does anyone have a suggestion on how to clean the inside of my lower reservoir while I wait on my backordered tail light switches? Thanks! _________________ 71 Westfalia
73 Beetle |
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busdaddy Samba Member
Joined: February 12, 2004 Posts: 51145 Location: Surrey B.C. Canada, but thinking of Ukraine
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Posted: Fri Aug 06, 2021 6:06 pm Post subject: Re: Brake servo? |
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Simple green and hot water, maybe a hand full of pea gravel in there as well. _________________ Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
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Nicholas D Samba Member
Joined: November 06, 2012 Posts: 225 Location: Charleston, SC
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Posted: Fri Aug 06, 2021 6:16 pm Post subject: Re: Brake servo? |
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Thank you! _________________ 71 Westfalia
73 Beetle |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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kreemoweet Samba Member
Joined: March 13, 2008 Posts: 3899 Location: Seattle, WA
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Sat Aug 07, 2021 10:45 am Post subject: Re: Brake servo? |
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I took the part number off the fiche. The only thing I can say on this is that on my 1977 I had to return the one BD sent me, and get the correct one from Bughaus. Bughaus doesn't list one for a 1971. That was 10 years ago and BD does mention the issue a the bottom of the page. Compare the old one before buying.
H
J
K
_________________ “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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