Hello, any help greatly appreciated. I was out for a Saturday afternoon cruise, 65 Riviera, 101K miles, mostly all original, replaced all the brake cylinders, all rubber lines and hoses, original master cylinder as far as I know, everything was working fine, turned the car off, came back 10 mins later, fired her up and when I tried to stop, had a rock hard brake pedal, needed to almost stand on the brakes to stop, and had a higher than usual idle. I checked all the vacuum lines, all tight.o No: ??? Thanks in advance for any help. John
Blown booster??? Do you hear a sucking sound from the dash??, or one that changes with brake pressure??? thats my guess...
Cap the vacuum line from the engine to the booster and see if it cures the idle. If so, the booster is toast. Note that a high idle with that big a leak indicates a pretty rich mixture.
Thanks Steevee, did what you said, idles like before, I am going to replace the booster, and saw on a few posts about switching to a dual master cylinder, do you know of any supply stores that would carry both, or recommend a name to get, would like to avoid any china stock if possible. Thanks again, John
Hard to say what you have in PA. Note that a lot of rebuilders will not sell you a booster without a master attached, I'd imagine because of all the variables they run into.
Found this today which might come in handy Borrowed some directions originally from July '96 Car Craft by Marlan Davis, for installing a late model dual diaphragm booster on an A body Buick, but this should work for your 65 Riviera The late-model dual-diaphragm power booster commonly available late-model cars (such as a 9" dual diaphragm booster from a 1982-1988 G-body, code "FB," GM 18010120) typically have a different firewall mounting angle and brake-pedal attaching rod than the early unit. The G-body booster can be modified allowing it to fit the early A-body (intermediate) with the following steps 1. From your bad booster grind off the rivet heads that hold the firewall mounting bracket to the booster. Pry the bracket off the booster with a screwdriver. 2. Measure and record the length of the pedal pushrod between the brake pedal clevis and the rear face of the booster. 3. Extend the length of the G-body booster’s pedal pushrod by first cutting the clevis end off. 4. With the clevis end removed thread a short section of the G-body pushrod that extends out from the booster body with a 3/8-16 die. 5. To the newly threaded end of the rod off the G-body booster, screw on a 3/8-16 coupling nut (McMaster-Carr #90264A210 or equivalent), using red Loctite(R) on the threads. 6. Either screw in a threaded section of the "A" pedal pushrod or use a section of Grade 8-quality 3/8-16 threaded rod to make the overall length of the G pushrod the same as that from the original "A" booster. (The length measured in step 2 above) Again use red Loctite(R) on the threads. 7. Attach the clevis from your old booster and retain with a jam nut. 8. Place the previously removed firewall-to-booster bracket on the "G" booster’s existing firewall-mounting studs, in the same orientation it came off the old booster, and fasten with self-locking metric M10x1.5 nuts. In some instances it may be necessary to elongate the "A" bracket’s mounting holes slightly inboard, with a rat tail file. 9. Attach the clevis rod to the brake pedal, then fasten the booster to the firewall using self-locking American 3/8-16 nuts. For low vacuum situations you may want to try a 12" dual diaphragm booster from a B-Body (such as a 1990 Caprice). You can use this same procedure above to swap in the larger diameter booster if you have sufficient room around the booster. Other Buicks with the correct 12" dual diaphragm booster include: Buick Electra Estate Wagon (1981 - 1989) Buick Electra Limited (1981 - 1984) Buick Electra Park Avenue (1981 - 1984) Buick Lesabre 1981 Buick Lesabre Custom (1982 - 1985) Buick Lesabre Estate Wagon (1981 - 1990) Buick Lesabre Limited (1981 - 1985)
