Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: marcia on July 29, 2009, 06:27:25 AM

Title: 1984 Eldorado replaced rear calipers and pad and won't bleed
Post by: marcia on July 29, 2009, 06:27:25 AM
Front brakes bled fine.  Went to rears and found emergency parts frozen up.  Bought new cables, calipers and pads.  While waiting for the cables to arrive we installed the calipers and pads, and attempted to bleed and fill the the new empty calipers.  Pedal would not push down to bleed and all we got was a dribble of fluid. Any suggestions?

We did block the emergency brake lever in the proper non activated position before we attempted to bleed. Light on dash is on and it had gone off after we did the front bleed.  Also is there any particular order that we should do a normal bleed in, as front first, rear first.  With no parts replacement as with these new calipers. Any help wold be greatly appreciated.  Marcia
Title: Re: 1984 Eldorado replaced rear calipers and pad and won't bleed
Post by: The Tassie Devil(le) on July 29, 2009, 06:42:02 AM
G'day Marcia,

When bleeding brakes, always start with the brake that is the furthest away from the Master Cylinder.

But, when no fluid is coming out, you need to check that the circuit isn't blocked along the way.

Seeing as you had frozen rears, it could well be that you have a problem in the rear line so I would be "cracking" the fittings starting at the rear, and attempt to bleed the brakes, working forward until you have fluid coming out the joints.

This will show you which part is blocked, and needs repairing.

Bruce. >:D
Title: Re: 1984 Eldorado replaced rear calipers and pad and won't bleed
Post by: Marcia on July 29, 2009, 07:25:59 AM
I'm thinking now that we may have tripped the proportioning valve and it may have shut off fluid to the rear. does that sound like a possibility?  How can we reset the proportioning valve or must it be replaced?
Title: Re: 1984 Eldorado replaced rear calipers and pad and won't bleed
Post by: The Tassie Devil(le) on July 29, 2009, 08:31:54 AM
There was a suggestion to press the button in the end of the Proportioning Valve.

Bruce. >:D
Title: Re: 1984 Eldorado replaced rear calipers and pad and won't bleed
Post by: marcia on July 29, 2009, 09:17:06 AM
Thanks, didn't know there was a button on the valve.  Will look for it and pray it solves problem.
Title: Re: 1984 Eldorado replaced rear calipers and pad and won't bleed
Post by: Dave Shepherd on July 29, 2009, 12:56:00 PM
Hold the button out to get full flow to the rear.
Title: Re: 1984 Eldorado replaced rear calipers and pad and won't bleed
Post by: paul on July 29, 2009, 09:58:18 PM
Hi i did a major rebuild on a 84 eldorado. its posted here. i had many problems that you to will be going through.       disconnect the line on the side of the master cylinder that feeds the rear. you could have a bad master. put your finger over it and have someone press the pedal. it should have strong pressure . i would then push some air through the disconnected line and see if the lines are free. myself i would blow or suck on it. yeah i know its gross and you get a mouth a full of old brake flud. been doing stuff like hat for over 30 years hasnt killed me yet. either somthings blocked or the master is bad.  im just a guest spo ill dig up the topic and post it again
Title: Re: 1984 Eldorado replaced rear calipers and pad and won't bleed
Post by: Carfreak on July 29, 2009, 10:06:01 PM
Might help; circa 1978 Cadillac Service Roundtable Four Wheel Disc Diagnosis:

http://www.modifiedcadillac.org/documents/1970s/1978/1978%20Brougham%20Seville%204%20wheel%20disc%20diagnostics/
Title: Re: 1984 Eldorado replaced rear calipers and pad and won't bleed
Post by: Guidematic on July 30, 2009, 10:36:12 AM

Before you get into any big investigations, try and gravity bleed the system. Open all of the bleeders and wait until clean fluid runs out before closing them off. Monitor the master cylinder to keep it topped up.

I am not aware of ant "button" on the proportioning valve. It is self centering and will return to it's centre position when equal pressure is found on both circuits.

Once you have the system gravity bled, you should be fine to bleed it in the conventional method. However, often when I have done this, there is no need for further bleeding.

Mike
Title: Re: 1984 Eldorado replaced rear calipers and pad and won't bleed
Post by: marcia on July 30, 2009, 11:12:35 AM
Thank you all so very much.  We did get the proportioning valve recentered by redoing the front bleed.  Two pumps on each side did it and got fluid flowing to the rear.  Gentle pumps took care of the rear bleed and all is now air free.  We started the car and after a few pumps on the brakes the brake light on the dash went out.  Hurrah!

We are now working on getting the rear emergency system to properly apply the pads to stop the car.  new cables go in today. and the round table manual which describes all the proceedures in order and in depth will be invaluable.  Carfreak thank you so much for that.

I will come back and let you know how the emergency brakes worked out.

Thank you again for all your help.
marcia