Hobo,NC
Well-known Member
- Location
- Sanford, NC
I have a 1970 C-10 with a 454 automatic it has a lite cam it idles well no problem with that. It came to me with the complaint of no power brakes and has not acted like power brakes since he brought it. It has a small 8 brake booster mounted on a bracket under the hood that looks OEM, it has what looks like factory front disc and rear drums everything looks new except the rear brake drums. I am familiar on how to diagnose a bad booster when you start the engine with your foot on the brake the brake pedal sinks a little then you have a rock solid pedal. The booster has a good supply of vacuum at idle (18) I have removed the vacuum supply down to the port in the intake checked/replaced the vacuum line to the booster. I went as far as to supply vacuum with a new line out of the back of the carb throttle plate (3/8 port). The booster DOES hold vacuum after the engine is shut down a new check valve was added because I had one. I am confident the vacuum supply is good, supply line and check valve and the booster. There is no issue with the pedal and linkage I have a full rock solid brake pedal. The master cylinder is new I measure its an 1-1/8 bore all brakes do apply tho the rear is a little weak. It stops badly with what seems like little power access if you shut the engine off you may not stop it
I wanted to put a hydra boost on it, it has power steering the owner gave the command to replace the booster I ordered an 8 booster from Speedway dual diaphragm #91031485 its no better: ( At this time I am thinking try a 1 master cylinder.
What are your thoughts are suggestions.
I wanted to put a hydra boost on it, it has power steering the owner gave the command to replace the booster I ordered an 8 booster from Speedway dual diaphragm #91031485 its no better: ( At this time I am thinking try a 1 master cylinder.
What are your thoughts are suggestions.