1968 eldorado master

[ANTHONY 20485]

 I rebuilt my 1968 Eldoardo powerbrake booster  last August by Booster Dewey, now my master is bad. I am unable to locate another, I can get a rebuilt powerbrake booster and master for a 69 Eldorado.I was wondering if I could just bolt up the 69 and would it be okay for the different calipers. Would anyone know if this is safe.

[anthony]

Does anyone know if booster mounting bolt pattern is the same for 68 & 69?

[Bruce Reynolds # 18992]

Gday Anthony,

Knowing General Motors, it wouldnt surprise me if the boosters in question were the same, as the 68 to 70 car is the same apart from normal facelifts.

Bruce,
The Tassie Devil(le),
60 CDV

[Steve Preston #16375]

Checker Auto http://www.partsamerica.com TARGET=_blank>http://www.partsamerica.com shows the master cylinder the same from 68 through 70. Their part number is: Cardon 101420 rebuilt about $30.00.

Autozone has the same number, about $36.00. http://www1.autozone.com TARGET=_blank>http://www1.autozone.com

As a note, Autozone shows the same part # for disc or drum up front.

[anthony]

I bought the master but it is not the same.  My master is similar to a 67 it has a 1 1/2 deep hole in back where booster pin goes into. The booster is different from 68 to 69. My part supplier cant even match the master  up. To resleeve master it would cost $230.00. I want to know if mounting bolts for booster are the same before I remove booster again. Real pain to work under dash. Thanks for the help.

[Porter 21919]

Dont know about the 68 Eldo but some years they used two different brands, in 66 they used Delco and Bendix PB boosters.

Try these websites and see what app. they show, sometimes I open up two windows and compare parts, my 66 & 67 CDV share most all parts.

http://www.napa.com TARGET=_blank>www.napa.com

http://www.rockauto.com TARGET=_blank>www.rockauto.com

HTH, FWIW

Porter

[Steve Preston #16375]

Are there any part numbers stamped on your master that would help us track it down for you? Damn, I loaned my Nephew in California my Master Parts book to learn how to use it. Ill email him and try to walk him though finding the part numbers for the master which might help.

Rock Auto shows several masters for a 67 Eldo and only 1 for a 68 Eldo. For the 67 they list them as shallow & deep push rod hole. You might want to call them @ 866-ROCKAUTO (1-866-762-5288) and discuss. Even the AC Delco is a lot less than the re-sleave you mentions, I think about $170.00

 

[anthony]

I bought the 67 from rock auto because it looked right, but it was not. The brake lines connect by engine the 67 connects by wheel well.

[alfredo barrenechea]

Does anyone know what the differences are between the drum/drum & disc/drum master cyclinders?
Im trying to put Discs on a 64 and I need to figure out if I need to change my 64 master cylinder/booster or if i can still use it and just change the prop valve/distribution block to a 70?
Thanks.
-alfredo

[Paul VW #21348]

1967 Eldorado, (Bendix, Disc Brake)  Part No. 149 0237

1967  (Bendix Exc. Disc Brake)   Part No.  148 9981

1967; 1968 exc. Eldorado  (Delco Morraine, exc. Disc Brake stamped HU 1 bore)  Part No. 546 3417

1968 Eldorado, 75, CC (Bendix, Disc Brake)  Part No. 149 2687

1968 exc. Eldo, 75, CC  (Delco Morraine, Disc Brake stamped AF 1 bore) Part No. 546 8867

1969 Eldorado  (Delco Morraine, Disc Brake stamped EA 1 1/8 bore)  Part No. 5469407

[Mike #19861]

 Disc brakes require greater fluid displacement than drum brakes, and such require a specific master cylinder. You will have to use one designed for a disc/drum application.

 If you look  at the reservoirs in a disc/drum system, you will see that one resrevoir is substantially larger than the other. This is due to the larger fluid requirement. You could adapt any master cylinder from a disc drum to your car. I would not attempt to use the stock master cylinder in a disc brake conversion.

  Mike

[Rob Gerace #16100]

I believe that all master cylinders used with drum brakes have what they call a residual pressure check valve on the ports lines that supply drum brakes.  This valve keeps some pressure in the drum brake lines, so that you dont have to press the pedal as much to overcome the return spring force, which disc brakes obviously dont have.  So, using a drum/drum master cylinder with a front disc conversion might not allow your front brakes to disengage all the way.  

Im not sure if this makes a difference or not, but drum brakes are self-energizing, whereas discs are not.  I would guess that the master cylinder would be specifically designed to supply the right amount of fluid to either a caliper or a wheel cylinder.  Especially since the pistons in a wheel cylinder are a different size than those of a caliper.  So, my guess is that they would be different because of that.  

Rob

[Kelly Spors]

Did you convert to four wheel disk system?  Friend harvested 78 systems and converted 69 to four wheel disk, I will ask him about master cylinder.

I rebuilt my 1968 Eldoardo powerbrake booster  last August by Booster Dewey, now my master is bad. I am unable to locate another, I can get a rebuilt powerbrake booster and master for a 69 Eldorado.I was wondering if I could just bolt up the 69 and would it be okay for the different calipers. Would anyone know if this is safe.

[Viator Trudeau #8697]

Anthony; I sent my master cyl. in for rs-sleeving and rebuilding,two yrs. ago to a business in Minneapolis or St. paul, MN. Coat $ 125.00 then.  My ELDO has disk brakes in front and drumb in rear. The M S has to be the deep hole piston. The out let fittings are on the inboard side.  The rear chamber is much smaller for the rear brakes. The re-sleeving shop is advertisings in Hemmings.