brake booster problems

Maintenance advice to keep your Spider in shape.
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dmwhiteoak
Posts: 1088
Joined: Mon Aug 15, 2011 1:12 pm
Your car is a: 1972 Fiat 124 spider
Location: White Oak Tx

brake booster problems

Post by dmwhiteoak »

I have researched and have seen no sign of my problem at hand. I have been boosterless for two years and have just now installed a good one. When the booster vac hose is connected the pedal will not relieve back up to the position to disconnect the brake light switch. Unless you kinda pop it the brakes will stay engaged and you have to pull the petal up to release them. After much thought Im kinda figuring that fitting that goes to the booster must have a check valve. Am I right or wrong? If I am wrong what would most likely be the issue? At the moment the booster vac line is disconnected and the petal travels all the way up with no issues.
Dennis Modisette

1972 124 Spider
2003 Chevrolet Z71
2007 GMC Yucon
So Cal Mark

Re: brake booster problems

Post by So Cal Mark »

sounds like an internal issue with the booster. A check valve would only allow assist with the engine off
narfire
Posts: 3959
Joined: Sat Dec 27, 2008 2:14 am
Your car is a: 1980 124 spider
Location: Naramata B.C.

Re: brake booster problems

Post by narfire »

I guess you know there is an up and down on the booster. This is for the connection to the pedal, not so much for aligning the mounting holes.
Ask me how I know...
Chris
80 FI spider
72 work in progress
2017 Golf R ( APR Stg. 1)
2018 F350 crew long box
dmwhiteoak
Posts: 1088
Joined: Mon Aug 15, 2011 1:12 pm
Your car is a: 1972 Fiat 124 spider
Location: White Oak Tx

Re: brake booster problems

Post by dmwhiteoak »

Chris I don't understand. The up and down ?
Dennis Modisette

1972 124 Spider
2003 Chevrolet Z71
2007 GMC Yucon
narfire
Posts: 3959
Joined: Sat Dec 27, 2008 2:14 am
Your car is a: 1980 124 spider
Location: Naramata B.C.

Re: brake booster problems

Post by narfire »

What I found when I replaced my booster last year was the rod lined up better with the pedal when the booster was mounted one side(top-bottom) or the other. I tried rotating the plunger but still was not lined up right and would be difficult to connect. I've had boosters with the vacuum line one side or the other so took a chance and failed the first time. perhaps my brake pedal was out of whack but I turned the booster upside down and the connection lined up way better. Perhaps just unique with my car but I'm happy now.
Weird I know....
Chris
80 FI spider
72 work in progress
2017 Golf R ( APR Stg. 1)
2018 F350 crew long box
dmwhiteoak
Posts: 1088
Joined: Mon Aug 15, 2011 1:12 pm
Your car is a: 1972 Fiat 124 spider
Location: White Oak Tx

Re: brake booster problems

Post by dmwhiteoak »

When vacuum is applied is the only time the pedal does not retract .It worked fine on the car I removed it from. I will run booster less for now and when time allows I will solve this. That's one thing about these cars, when you change something you never know what to expect. :?
Dennis Modisette

1972 124 Spider
2003 Chevrolet Z71
2007 GMC Yucon
vandor
Posts: 3996
Joined: Sat May 23, 2009 1:23 pm
Your car is a: 1971 124 Spider
Location: Texas, USA

Re: brake booster problems

Post by vandor »

Do you have a return spring on the pedal? The pin that holds to pedal to the booster's fork has a tab for a spring connection.
Csaba
'71 124 Spider, much modified
'17 124 Abarth, silver
http://italiancarclub.com/csaba/
Co-owner of the best dang Fiat parts place in town
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