"odd" brakes?

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sh0rtlife
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"odd" brakes?

Post by sh0rtlife » Thu Jun 08, 2006 2:00 pm

ok i just rebuilt all 4 calipers ..i vacume bleed the entire system but the brake pedal is still spongy...pump it up and its fine till you let it come to rest for a few secs then its back to spongy again...i proped the pedal down a lil over half way and the fronts are working as in i cannot turn them..but at the rear there just grabbing a little....soooooo did i loose the mc?...and whats the item under the car at the rear with the brake lines going thru it...ive never see anything like it on an american car..i asume its for front/rear bias....could it be causeing anything?
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Post by MD » Thu Jun 08, 2006 3:22 pm

From what I am reading, I would suggest that you invest in a workshop manual for you vehicle, have a read before you proceed. You will find not only short cuts but usefull hints and an explanation of what things are for.
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Post by sh0rtlife » Thu Jun 08, 2006 5:37 pm

got one in pdf? or another downloadable form?.....where would i go about finding one? id buy a chiltons manual for it but they dont seem to make one
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Post by Mats » Thu Jun 08, 2006 11:22 pm

Most of those problem might go away if you actually drive the car. I have had a lot of "impossible bleeding problems" that went away after a drive.
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Post by sh0rtlife » Fri Jun 09, 2006 7:28 am

dont like the idea of driveing it like this to see what develops...but ive driven worse......this silly alfa doesnt fit into the normal problem line i would expect from the classic mopars and fords that ive been working on for 15+ years
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Post by MD » Fri Jun 09, 2006 2:17 pm

Try this site:

http://www.aroc-usa.org/tech/manuals.asp

I am just a little concerned that if you do not know what that "thing in the back" is, it is an idication that you need to know much more before you tackle important things like brakes that could either kill you or other people if you do not understad what you are doing.

Just trying to help.
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Post by sh0rtlife » Sat Jun 10, 2006 8:34 am

i understand the concern MD ...im not some idiot trying to work on it..im just not verseed well in the alfa way of things...ive restored many a car all the way down to every last nut and bolt with MY own hands..the only work i farm out on anyone..ever is automatic trans rebuilds and engine block machine work...but i assemble and build the engine..i prefer to work on 50's 60's and early 70s stuff..i fabricat patch panels from scratch by hand all my own paint and body work..you name it ive probably done it by now...even HUGE patches like roof swaps

my instinct told me that the inline device under the back seat inline of the rear brakes was a proportioning or "bias" valve..im just used to seeing them up front and connected to the front lines as well
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Post by Murray » Sat Jun 10, 2006 3:02 pm

Shortlife I believe that older GTV6's may have had the proportioning valve back there but I'm not 100%.My 86's is right next to the master.Bleeding this system can be a real B%$#.You have to jack the rear end way up in the air and start with the pass.rear caliper.Keep in mind that the rears have two bleed screws per caliper.Next do the driver rear pass front and then drivers front.Try this and report back.
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Post by Zamani » Sat Jun 10, 2006 3:15 pm

My mechanic said gravity bleeding is the best method. If you start applying pressure on the system the bubbles may form smaller bubbles.

Maybe what you can do is do some basic bleeding on the whole system first. Then go drive around for a few miles. Before you have dinner, jack the rear end of the car up, undo the brake reservoir cap, devise a system to drip new brake fluid into the reservoir, then open the rear calipers' bleed screw and let the brake fluid to flow out . Let it stay like that for a few hours and you should have almost no bubble in the system. It mat consume the whole big bottle of brake fluid (about 1 quart or 0.946L) in that period of time. The cost of DOT3 fluid is pretty cheap. Just don't forget to tighten the bleed screw after dinner.
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Post by gtv11636 » Sat Jun 10, 2006 3:31 pm

Is it realy necessary to Jack up the rear end even when using a pressure bleeder ?

BTW - all GTV6\GTV4\Alfetta's etc untill 1984 Including! came with the proportioning valve under back seats.

Later models came with proportioning valve near MC.
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Post by sh0rtlife » Sun Jun 11, 2006 8:18 am

ok good i figured it was the prop valve mounted in an unuseual location(or atleast unuseual to someone working on american classics)....ill see how high i can get the tail and see what developes..ive vacum bled the system about 6 times now...the front has NO air in it period..the rear is questionable....tho i did start it up and run it in 1st gear and aplyed the brakes and it is stoping the engine..will try bleeding again today ....im quite happy with the rebuild on the calipers...tho those rears are the stangest things ive seen...and i thought me old 4 pot K/H from my cuda were wierd :shock:
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Re: "odd" brakes?

Post by grega » Sat Aug 22, 2009 5:08 pm

I rebuillt my rear brake calipers. And have been having a hard time bleeding the system. no mater what i did, it seems the pedal is still spongy.

i finaly got it to work. So i thought i'ld share what worked for me

It seems you need to take a few days with the bleeding. i didn't use any vacum device. just someone in the car pumping. I started with the pasenger rear then the driver rear, then the pasenger front and the driver front.
I also jacked the rear of the car higher. in hopes that the air bubles would rise to the rear. I also found a bit of air came out of the front conection of the proportioning valve when i cracked the connection open.
Basically i did this a few times, while letting the car sit overnight. it took about 4 trys to get all the air out. She's good now.

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Re: "odd" brakes?

Post by Giuliettaevo2 » Sun Aug 23, 2009 2:12 am

On the dutch forum the first thing everybody would say when told of the brake-bleeding problem on a transaxle is to lift up the rear of the car...

And i don't mean a bit, but get it as high as you can safely get it! :wink:

On my 75"s i jacked up the rear so high that the front bumper almost hit the ground and it worked wonders... :D
Drive it like you stole it...
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