My 1991 Buick Regal Gran Sport leaks brake fluid from the firewall side of the master cylinder. It only leaks when brake pedal is applied. When the master cylinder was available from GM the part's cost was over $1800 because this unusual GM design of the master cylinder included the ABS module. I never found a used unit for less than $900 and gave up fixing it 10 years ago. A few years agoI decided to try to get this beauty on the road and checked with a GM dealer on how much to install if I found a used unit, since it is no longer available new. They sent me to the only dealer in the area that still has some moth balledspecial GM equipment required to install the unit. They couldn't guarantee anything and I don't remember the outrageous quote they gave me, so I gave up again. Well Uncle Sam is sending me $1200 and I was just wondering if anybody out there is familiar with this Master Cylinder / ABS Unit fiasco and maybe can guide me with some straight what to do knowledge. This was my late father's last car and I really would like to keep it.

www.rockauto.com






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<TD>ACDELCO Part # 18M874 {replaces 18013994}
ACCUMULATOR,BRK M/CYL FLUID DURAST0P; w/ANTILOCK DISC BRK(JL9)</TD></TR></T></TABLE>
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<TD class=center id=node311part5price>$169.79</TD></TR></T></TABLE>

Thanks Wes, but I'm pretty sure thats not really the master cylinder. In fact I think I ordered that part (about 5 yrs ago) and it turned out to be something entirely different. Ifit's the same part i ordered, it's a tennis ball size metal ball - almost looks like a float.Please look into this a little more, it is about twice as big as the normal master cylinder. I can attach a picture if u like.

i know what your're talking about. i see that large, odd looking m/s on many W bodies at the junkyard. but i think the one at rock auto is the replacement for you. if you call them, or send them an e-mail, im sure they can confirm.

I sent Rock Auto the attached photo of this special master cylinder. Take a look yourself, I'm curious if it was what you thought it was.[img]uploads/Daddioman/Regal91_MasterCylinder.jpg[/img]ma

yes, thats the one i have seen in the yard. did you get a response from rockauto yet?





btw, off topic, but is that a late 91, cuz it looks like it has the 92 engine. and is there an egr?

Yes it is a late model 91 - I did not know it was a 1992 engine.


Here is the response from Rock Auto:


The AC Delco 18M874 is the accumulator ball for the ABS system, and not a complete hydraulic (master cylinder/ ABS pump)unit.
On the Gran Sport, the master cylinder is integral with the hydraulic
assembly, which we sell:
1991 BUICK REGAL 3.8L 231cid V6 MFI (L) : Brake/Wheel Hub : ABS Hydraulic Unit A-1 CARDONE Part # 123307 {remanufactured}
Item Price Core Total
$1,278.79 $100.00 $1,378.79

OMG!!! that is outrageous.





I can keep my eye out next time I'm at the JY.





Is there a way to convert that to what most of the other W bodies had?

I can't find anybody that knows anything about this GM fiasco, let anlone how to convert it. I think my best best is to watch for a used car with this crazy Master Cylinder in it- I might get lucky and get the whole car for plenty less thanthan $1300 !!!!!





Seems like someody could figure out how to rebuild the thing for alot less. Gee

why cant you just pull the abs fuse and have the standard M/C