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zerotofifty
Samba Member
Joined: December 27, 2003
Posts: 2848
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 Posted: Thu Dec 05, 2024 10:18 am Post subject: Re: CRASH3D GRANDMAS CAR,BRAKE FAILURE!!! After two decades |
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| shanered wrote: |
Quick prelude to update, maybe found the culprit I believe.... maybe... The master cylinder although casting is sloppy doesn't seem to have any obvious flaws, it's quite dirty and the mysterious brake switch I had plugged into the front circuit has a millimeter less thread than the one inthe rear circuit and seems to have been bottomed out on the housing not the sealing area.... It was like this a couple years and was not leaking externally but logically seems like it could let air in on the plungers return which me brain thinks may let a bit of air in and not get quite the pump your expecting on the next stop....  Still not 100 percent but I've got some pics and videos to upload and a new German master cylinder from jbugs on the way which I will install without altering or adjusting anything else and we will see if the problem persists. Thanks again everyone for all of the good advice and perspective, if this helps anyone or prevents any injuries, vw related nose jobs flesh or steel worth all the time spent on the screens right.? |
If the fitting did not leak fluid out, it unlikely leaked air in. That fitting is exposed to fluid braking pressure, it should have leaked out fluid if it also let air in. If air ingress was gradual, you would have experienced spongy brake well before the crash. I think this diagnosis is not correct given that you say it did not leak fluid out.
The stock switch has a tapered thread, there is no sealing surface other than the threads |
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shanered
Samba Member
Joined: October 24, 2022
Posts: 60
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| Posted: Thu Dec 05, 2024 3:27 pm Post subject: Re: CRASH3D GRANDMAS CAR,BRAKE FAILURE!!! After two decades |
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| zerotofifty wrote: |
| shanered wrote: |
| Quick prelude to update, maybe found the culprit I believe.... maybe... The master cylinder although casting is sloppy doesn't seem to have any obvious flaws, it's quite dirty and the mysterious brake switch I had plugged into the front circuit has a millimeter less thread than the one inthe rear circuit and seems to have been bottomed out on the housing not the sealing area.... It was like this a couple years and was not leaking externally but logically seems like it could let air in on the plungers return which me brain thinks may let a bit of air in and not get quite the pump your expecting on the next stop.... Still not 100 percent but I've got some pics and videos to upload and a new German master cylinder from jbugs on the way which I will install without altering or adjusting anything else and we will see if the problem persists. Thanks again everyone for all of the good advice and perspective, if this helps anyone or prevents any injuries, vw related nose jobs flesh or steel worth all the time spent on the screens right.? |
If the fitting did not leak fluid out, it unlikely leaked air in. That fitting is exposed to fluid braking pressure, it should have leaked out fluid if it also let air in. If air ingress was gradual, you would have experienced spongy brake well before the crash. I think this diagnosis is not correct given that you say it did not leak fluid out.
The stock switch has a tapered thread, there is no sealing surface other than the threads |
I agree, but was not leaking long enough to notice and when the scenario was attempted to be duplicated and pedal would hold with no fade, then without warning on next pump just nothing. Next pump, right back to top no fade.. It was an eerie feeling, 20 years experience w brakes, hundred cars and a dozens Master failures....never had that. |
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shanered
Samba Member
Joined: October 24, 2022
Posts: 60
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| Posted: Thu Dec 05, 2024 3:38 pm Post subject: Re: CRASH3D GRANDMAS CAR,BRAKE FAILURE!!! After two decades |
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shanered
Samba Member
Joined: October 24, 2022
Posts: 60
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| Posted: Thu Dec 05, 2024 3:41 pm Post subject: Re: CRASH3D GRANDMAS CAR,BRAKE FAILURE!!! After two decades |
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 the shorter switch was on the rear brakes |
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KTPhil 
Samba Member
Joined: April 06, 2006
Posts: 35205
Location: Conejo Valley, CA
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| Posted: Thu Dec 05, 2024 3:47 pm Post subject: Re: CRASH3D GRANDMAS CAR,BRAKE FAILURE!!! After two decades |
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Fuel line is not brake fluid resistant. I wonder if the hoses broke down internally and clogged a port in the master or wheel cylinder.
_________________
Current Fleet:
- '71 Fastback
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Retired:
- '67 Beetle
- '65 Beetle (x2)
- '65 Bus
- '71 Squareback |
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shanered
Samba Member
Joined: October 24, 2022
Posts: 60
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| Posted: Thu Dec 05, 2024 4:01 pm Post subject: Re: CRASH3D GRANDMAS CAR,BRAKE FAILURE!!! After two decades |
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| KTPhil wrote: |
| Fuel line is not brake fluid resistant. I wonder if the hoses broke down internally and clogged a port in the master or wheel cylinder. |
I think you're on it, check out the debris in video. Those hoses are 15 years old.
Link
Link
Last edited by shanered on Thu Dec 05, 2024 4:09 pm; edited 1 time in total |
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shanered
Samba Member
Joined: October 24, 2022
Posts: 60
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| Posted: Thu Dec 05, 2024 4:07 pm Post subject: Re: CRASH3D GRANDMAS CAR,BRAKE FAILURE!!! After two decades |
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Hakka
Samba Member
Joined: November 21, 2004
Posts: 621
Location: PNW or Norway
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| Posted: Sat Dec 07, 2024 9:43 pm Post subject: Re: CRASH3D GRANDMAS CAR,BRAKE FAILURE!!! After two decades |
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Frame head looks bent. Door statement is a hard one also. Without a lot of metal work and careful measuring this car is toast.
Sorry to hear about your situation. |
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zerotofifty
Samba Member
Joined: December 27, 2003
Posts: 2848
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| Posted: Sat Dec 07, 2024 9:58 pm Post subject: Re: CRASH3D GRANDMAS CAR,BRAKE FAILURE!!! After two decades |
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| I dont see the bent frame head, which photo? |
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zerotofifty
Samba Member
Joined: December 27, 2003
Posts: 2848
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| Posted: Sat Dec 07, 2024 10:00 pm Post subject: Re: CRASH3D GRANDMAS CAR,BRAKE FAILURE!!! After two decades |
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| What year Bug? you got a collapsible steering shaft, that is modern. but peanut front signals, and i am trying to figure what front bumper mount. |
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shanered
Samba Member
Joined: October 24, 2022
Posts: 60
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| Posted: Sun Dec 08, 2024 9:28 am Post subject: Re: CRASH3D GRANDMAS CAR,BRAKE FAILURE!!! After two decades |
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Yes thats a collapsable section, I did that years ago after pistol petes accident, you can probably still find the old thread here.. And yes, sadly the pan is massively bent. Most of the impact was taken by the drivers front tire. I can straighten it again... The whole front clip is from taiwan. My grandmother had crashed it once before in 1971 and the pan heads been straightened once already. I tacked the free to me clip on a decade ago to make a driver out of it never finished because it didnt fit very well. The gas tank supports were fully replaced and welded but I neved finished the sheet metal work.
I think Phil nailed it, clogged up my brakes with rubber. Seen it a hundred times in a carb, I guess enough rubber in thr brakes is not good... |
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kvasilak
Samba Member
Joined: February 28, 2024
Posts: 48
Location: Minnrsota
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| Posted: Mon Dec 09, 2024 1:57 pm Post subject: Re: CRASH3D GRANDMAS CAR,BRAKE FAILURE!!! After two decades |
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so the Root cause was non brake fluid resistant line in the remote fill?
Makes sense, dirt in the seal and oops no brakes. |
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shanered
Samba Member
Joined: October 24, 2022
Posts: 60
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| Posted: Tue Dec 10, 2024 9:05 am Post subject: Re: CRASH3D GRANDMAS CAR,BRAKE FAILURE!!! After two decades |
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| Yes the front brake circuit inlet was particularly dirty, I believe this is what caused the problem. I admit I had been neglecting the maintenance recently. Overloading yourself, and your schedule is not good. I was doing full time, training someone and wasn't keeping my schedule tight. I was going for a fast food dinner 10 miles up the road after working 14hrs when I crashed. Also had parked the car a week prior due to a "funny feeeling" and decided to hop it in that nite care free... dumb ass decision. |
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shanered
Samba Member
Joined: October 24, 2022
Posts: 60
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| Posted: Wed Dec 18, 2024 9:27 am Post subject: Re: CRASH3D GRANDMAS CAR,BRAKE FAILURE!!! After two decades |
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Out of the 4 small hose sections two were extremely swollen and deteriorating, the two lower sections were ps return hoses, the ones tucked under my reservoir are a mystery because I don't remember installing or buying, but it started out as a thrifty build and was refined over the years but obviously I had overlooked those hoses sections when doing maintenance. |
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