1968 Eldorado Brake Master Cylinder Nightmare

Started by Forgiven1989, January 23, 2013, 06:52:40 PM

Previous topic - Next topic


My master cylinder on my 68 Eldorado was leaking so I sent it to Cardone through NAPA to get rebuilt because none are available.  Received it back and installed it.  2 weeks later it is leaking again.  Now Cardone says it may need a new booster because it may allowing the brake rod to go into the master c. too far.  Any ideas?  Thanks.    UPDATE;  Here is the latest from Cardone;  They are saying that my brake booster is bad and it is sucking the fluid out of the back of the rebuilt MC.  Has anyone ever heard of that?  Thanks.

The Tassie Devil(le)

G'day David,

If you received your old MC back, rebuilt, then I would be sending it back, as unless you have changed the M/C in the meantime, it is their problem.

But, before doing anything further, check the position of the Pushrod length out of the Booster, against the depth of the M/C Piston, measuring from the relative mounting surfaces.

A correctly built MC should never leak, but don't strip it down as if you do, they will have a reason to avoid honouring your Warranty Claim.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

Dave Shepherd

Good advice by Bruce, to add the pushrod should have about 1/8 free play in the m/c, also I wouldn't let Cardone touch any of our parts, I've trouble had with reman axles and electronic components from them, are you sure Rockauto does not have a new one?


No Rock auto does not carry a new MC for the 68 eldorado.

Dave Shepherd

Next time you need this done, White Post Restorations in VA. Or do it yourself like we do in my shop, no sleeved cylinders though so if rust pitted beyond our limits off it goes the WP.

CEC #20099

I had Cardone rebuild my 88 F150 ABS control valve, thru Rockauto. Never worked right out of the box. Disconnected ABS & Regular brakes 100 % better. Cardone used to have a good reputation .......
c chleboun # 20099

Steve W

I got my replacement m/c from a local auto parts store. Its probably a rebuilt or reman, but it was readily available. Works great! I don't know if an Eldorado uses a different m/c than a Coupe deVille though...
Steve Waddington
1968 Coupe deVille
North Hollywood, CA
CLC Member # 32866


The lines on the 68 Coupe Deville are on the opposite side of the unit.  It won't work on the 68 Eldorado.


The M/C for the 68 Eldo is used on only the Eldo the 75 series and the Commercial Chassis.  All 68s for Cadillac only.  Not sure about other makes/models
Glen Houlton CLC #727 
CLCMRC benefactor #104

Viator Trudeau

In apx. 1989 i had my master cyl. on my '68 ELDO.  This model had the lines on the inboard side.

Isent to cardone for rebuilding. It cost $45.00 plus shipping.  A short time later it was leaking.  I took it apart and discovered a rust track on the bottom of the cylinder caused by water laying there. that they did not remove enough metal when honing.  I finally honed it smooth after a couple hours.  It leaked 4-5 years later, I sent it in to a re-sleever in  ST. Paul, MN. 
V. Trudeau


White Post in VA has been doing these for years.  I don't know if they can specifically do your 68 Eldo MC but they have a great reputation for these repairs.  Hopefully the seals inside are the same as other GM units.

Brian Rachlin
Huntingdon Valley, Pa
CLC # 22443
I prefer email's not PM's rachlin@comcast.net

1960 62 Series Conv with Factory Tri Power
1970 DeVille Conv
1970 Eldo
1970 Caribu (?) "The Cadmino"
1973 Eldorado Conv Pace Car
1976 Eldorado Conv
1980 Eldorado H & E Conv
1993 Allante with Hardtop (X2)
2008 DTS
2012 CTS Coupe
2017 XT
1956 Thunderbird
1966 Olds Toronado

TJ Hopland

I'm pretty sure that St. Paul company still exists.   A friend used them recently to rebuild the brakes in his 50 nash.   I seem to recall it did not even seem expensive.   If someone else does not know the name I can ask. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason