I have a 1970 GS 455....new master, all new lines, everything new up front. I did use the parts car rear without changing the cylinders. The car stops, but the resevour looses fluid in the rear ( for the rear brakes), but I dont notice and fluid on the garage floor. I have checked all the connections. o No: Also, I wouldnt say this thing stops on a dime. My 72 Lark bone stock, with all drums stopped better than this beast with discs up front. The pedal feels soft. I do not know much about brakes. When I have a friend sit in the drivers seat, I hook the hose and catch can up to the bleed valve, I open it, and clean clear fluid comes out. No air bubbles. and yet I keep losing fluid? o No: Where is is going? Im really not a mechanic.....somebody please help, maybe Im bleeding them wrong, but I did the fronts, and they work good. thanks, Rob
When you state "new master", is that a new cylinder or a reman unit????? I have had lots of problems with poorly reblt remans and do not buy them. I buy new TRW units. As for disappearing fluid, I would inspect the rear cylinders first. Next I would remove the master from the booster and see if the booster seal is wet w/brake fluid. If so, your master is no good. Since you have disc brakes on your 70, do you have the hold-off valve mounted to the master? If not, you have a problem. The hold-off (name implies) prevents the front calipers from grabbing the rotors until the rear drums activate. If you don't have the hold-off, you have two choices: 1. Get a hold-off, I believe www.inlinetube.com sells them 2. Get the 71-2 combo valve for disc brakes
george, it is a proportioning valve. the prop valve for the 1970 disk brakes is right close to the master cylinder. as for the loss of brake fluid, i agree with george that perhaps the rear seal of the master cylinder is defective & the brake fluid is leaking into the booster and will destroy it. however, check those rear cylinders for a leak, and donot mistake rear axle seepage for brake fluid. usually if a wheel cylinder leaks, that drum/wheel will grab like crazy. brake fluid destroys the brake shoe lining, also.
reply You guys were right, all the seals in the rear were bad, cost me $100 and no more leaks and the car stops great. I do however now need to change the rear. I was thinking of going with a chevelle 12 bolt that has disc brakes. Do I need to change the proportioning valve as well? I would imagine so, but i dont know. Rob
Rob, Depends on what rear disc set-up you use. The article I wrote for our site uses the 79-85 Eldo, Toro, Riv, Seville rear calipers which are quite small (piston volume). If you have any problems, www.inlinetube.com carries several prop/combo valves for 4 whl disc brakes.
