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1993 Bonne - new master cylinder

Hi all ! I have a 1993 Bonneville with 135k miles on it. The brakes were working fine however the master cylinder was leaking at the rear seal. I went ahead and put in a new master cylinder however now I can not get the brakes to work. I've bled the brakes several times (I've bled other brakes in the past and assuming there is no special method of bleeding these brakes, I'm sure I did it properly). Based on old info posted in this group, I thought I may have a faulty new master cylinder so I went ahead and got another new one --- same problem.

The problem with the brakes is no pressure. The pedal goes all the way to the floor.....If I pump the brakes - I'll get brakes but they are very spongy.

The hose that comes off the master cylinder reservoir and goes down near the radiator - I assume that is the ABS system. Is there anything I need to do to that unit to bleed the brakes ?

Any other ideas ?

THANKS

Reply to
John B. Parisi
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You did bench bleed the master cylinder B4 installiing, right? GW

"John B. Parisi" wrote:

Reply to
Geoff Welsh

Keep bleeding them. There is air somewhere. The ABS pumps are close to the mstr cyl and connected by several steel pipes (not hoses). You are right about bleeding them - nothing special to do or watch for.

Reply to
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So now that I am beyond all frustrations I went out and bought the manual......Who would have thought one would need the manual for such a simple task. At any rate......

The manual states : "For 1994-1999 vehicles with ABS, after bleeding the brake system you must perform, an 'Auto Bleed' sequence, using a Tech 1 or equivalent scan tool. If you do not have access to a suitable scan tool, your vehicle will probably have to be towed to a shop with the proper diagnostic equipment to have the procedure performed."

What the heck is this about ? Even though my vehicle is a 1993, it is a late model 1993 and I think I might be running into this issue. Anyone else run into this or know about this 'procedure' ???

As usual THANKS for the help !

John

Reply to
John B. Parisi

I did my 94 with ABS and they were fine ... But I've never changed out the master cylinder.

Reply to
clevere

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