Restoration stopped by brake issues!

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Funcar
Posts: 195
Joined: Mon Nov 11, 2013 7:24 am
Your car is a: 1972 Fiat Spider 124
Location: Kitchener Ontario Canada

Restoration stopped by brake issues!

Post by Funcar »

I have been working on and off on getting a 73 spider on the road as it hasn’t run for about 25 years. Currently I have it at my mechanics who is the PO. The current problem is we cannot bleed the rear brakes. The front brakes work fine. My mechanic says it is the distribution block valve under the hood. He calls it a proportioning valve. It is necessary because if the brakes leak it will still allow brake fluid to flow to the other brakes so you can get stopped and fix the problem. The rational is that after sitting for 25 years the fluid has solidified and clogged the valve. We did get a lot of dirty fluid out of the front bleeder but now it runs clean brake fluid. See picture.
Image

I called AR and got Csaba. He knew immediately what part I was describing and explained it’s use and interestingly the history of the part which was used on the early models and discontinued after 2-3 years and replaced with a float. He advised me to bypass it and hook up the left front brake using a longer brake line. He said I may be able to get one locally from the Fiat club. He made me feel pretty good and assured me if I couldn’t get the parts he would find one for me. The rear brake line is long enough to attach to the master cylinder. He mentioned this was a hard part to find brand new. He also mentioned to go to this form and read the details which I did. :oops:

I did find this part on another vendor’s website. It is used and the vendor states: Condition: USED (8 of 10)
Good used condition. Should be disassembled and cleaned internally before installation.

I met with mechanic and explained what I learned. He said he would not by pass this valve as it was a intricate part on all cars for safety reasons. He was not for buying a used one and cleaning it as this would not guarantee it will work. I have been looking on the net for a new one with no luck. In the interim I got an e-mail from Ramzi telling me he had by passed his but that if I wanted he would search for a new one. Talk about customer service. :D

I went to see my mechanic...by the way he is a great guy and told him I was postings my issue on this form and would e-mail him the results. Thanks for any and all explanations.
Glen
Kitchener ON Canada
73 Fiat Spider 124
BEEK
Posts: 1833
Joined: Wed Mar 24, 2010 10:45 pm
Your car is a: 1975 Spider
Location: clermont fl

Re: Restoration stopped by brake issues!

Post by BEEK »

i would bet that the part under the hood is good. Your mechanic is thinking that this is like an american car and that part is a proportioning valve, it is not. all it does is turn on the light if there is a brake system imbalance. fiat decided that this part was unneeded and did away with it themselves. now back to your issue. i would bet that the real "proportioning valve" compensator is bad. it is not allowing fluid to go to the rear brakes. test this by loosening the lines to the rear from the under hood block, then see if it passes fluid, which i will bet it does. then look above the rear end on the passenger side, connected to a 3/8" rod you will find the culprit, replace that and all will be good, at least to that point.
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
Daniel

Re: Restoration stopped by brake issues!

Post by Daniel »

I think Beek is on the right path
amawds

Re: Restoration stopped by brake issues!

Post by amawds »

BEEK wrote:i would bet that the part under the hood is good. Your mechanic is thinking that this is like an american car and that part is a proportioning valve, it is not. all it does is turn on the light if there is a brake system imbalance. fiat decided that this part was unneeded and did away with it themselves. now back to your issue. i would bet that the real "proportioning valve" compensator is bad. it is not allowing fluid to go to the rear brakes. test this by loosening the lines to the rear from the under hood block, then see if it passes fluid, which i will bet it does. then look above the rear end on the passenger side, connected to a 3/8" rod you will find the culprit, replace that and all will be good, at least to that point.
To further this, make sure you two are bleeding the rear brakes with the rear axle jacked up. If it is dangling freely from the body, that valve that BEEK mentioned will be closing off the brake lines to the rear entirely. Usually it fails by locking up in whatever position it was in for an extended period of time. Mine was locked open.
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perthling
Posts: 349
Joined: Wed Jan 09, 2008 11:04 pm
Your car is a: 1974 124 Spider
Location: Western Australia

Re: Restoration stopped by brake issues!

Post by perthling »

amawds wrote: To further this, make sure you two are bleeding the rear brakes with the rear axle jacked up. If it is dangling freely from the body, that valve that BEEK mentioned will be closing off the brake lines to the rear entirely.
+1 - this was an issue my so-called Fiat brake expert encountered and when I dropped in to try and diagnose I couldn't believe that the car was up on a hoist under the jacking points, with the rear axle at its fullest droop.

Needless to say I haven't been back.
_______________________
Perthling
1974 Fiat 124 Spider (blade bumper 1756cc)
1974 Fiat 124 CC (same family since new)
1975 Fiat 124 CC (project)
1969 Fiat 124AC (project)
1997 Coupe Fiat 20VT (daily driver)
http://www.fiatlancia.org.au
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