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aeromech Samba Member
Joined: January 24, 2006 Posts: 16970 Location: San Diego, California
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Posted: Tue Jun 28, 2022 8:46 pm Post subject: Re: 1976 Bus: Sudden Loss of 50% of Braking Power - Ideas? |
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I worked on an 89 Vanagon a few months ago. The right front caliper had what looked like brown mud in it. _________________ 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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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50347
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Posted: Tue Jun 28, 2022 8:52 pm Post subject: Re: 1976 Bus: Sudden Loss of 50% of Braking Power - Ideas? |
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aeromech wrote: |
I worked on an 89 Vanagon a few months ago. The right front caliper had what looked like brown mud in it. |
In many parts of the country that is pretty common. It's not unusual to need to remove the bleeder and use a wire to open up the port in the caliber or slave cylinder to get it to bleed. |
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aeromech Samba Member
Joined: January 24, 2006 Posts: 16970 Location: San Diego, California
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Posted: Tue Jun 28, 2022 9:25 pm Post subject: Re: 1976 Bus: Sudden Loss of 50% of Braking Power - Ideas? |
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I got a kit and rebuilt the calipers. I used shop air to remove the pistons. The first one I did made a huge blowback mess because I didn’t cover it with a towel first. I learned a lesson there _________________ 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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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Wed Jun 29, 2022 8:13 am Post subject: Re: 1976 Bus: Sudden Loss of 50% of Braking Power - Ideas? |
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just keep your fingers out of the way. The compressed air makes them go off like a 12 ga. _________________ “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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wagohn Samba Member
Joined: June 24, 2014 Posts: 740 Location: United States
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Posted: Sun Jul 03, 2022 2:33 pm Post subject: Re: 1976 Bus: Sudden Loss of 50% of Braking Power - Ideas? |
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Update: We took off the driver's side front wheel, pumped the brakes and held, and cracked open the bleed nipple. We got a 2ft squirt of clear brake fluid so Im assuming the front hydraulics are good and we have a "red herring" sticking caliper.
Brakes were still low at the pedal so we tested the rears again, but this time a little differently. We jacked up the rear-passenger wheel, pumped and held the brake. Sure enough the wheel locked, but this time we kept the brake pushed in and tried to rotate the wheel after 10 seconds or so. After 10 seconds, we could spin the rear wheel WITH the brake pedal depressed. Im thinking we have a semi-ruptured master cylinder seal that slowly releases the pressure to the rears.
Thanks to all _________________ 1976 VW Transporter, 2.0 FI Engine |
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wagohn Samba Member
Joined: June 24, 2014 Posts: 740 Location: United States
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Posted: Sun Jul 10, 2022 4:51 pm Post subject: Re: 1976 Bus: Sudden Loss of 50% of Braking Power - Ideas? |
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Fitted the new master cylinder, bled all the brakes and we're back in action! Brakes are strong again and pulling straight.
Thanks to all. _________________ 1976 VW Transporter, 2.0 FI Engine |
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