My shop manual told me to start LR(inner then outter) then RR(inner then outter), then LF, then RF. Not sure on the logic behind all of it. If I end up replacing the MC would you all recommend replacing the lines at the same time?

 

Im not a mechanic but I do most of the repairs myself, I would just change the master cylinder first and make sure the system works. What if the new master cylinder is bad and you changed the brake lines and calipers all at the same time? Now its that much harder to figure out the problem.
Same with changing spark plugs, I learned (the hard way) not to pull off all the wires at once, I just do one at a time. PG.

 

Good point in replacing only one element at a time hadn't thought about that. I'm going to take another look at everything and go from there. I'm out of town for a week so I'm going to have to put this project on hold. Thanks all for the advice, I'll let you all know what I end up doing, and how it goes. Thanks again.

 

o iI consulted with afriend who is a little more mechanical than myself . he thought it was the power brake system . iI listened to the motor while applying the brake and you can hear it affect a little bit but not a lot. iI pulled the hose off at the filter with the engine running and it's sucking air. wiI briefly sealed the iI t intake and the pedal became immediately solid. dontdon't k know if that means anything or not. When I hooked the power brake back up the pedal then required the large amount of travel again. Again not sure that it really means anything or not. It seems like I should maybe replace the MC and power brake. I really don't know how to troubleshoot the power brake unit. Any suggestioNs? I'm out of town for area days so this project will have to wait until I get back. I'm still going to try bleeding the lines first but I wanted to see if anyone knew how to test the power brake unit or had any more insight. Thanks all

 

On the front of the power booster is a check valve and a rubber hose that connects to a port on the back of the carburetor, with the motor running, if you remove the check valve or the hose you should have vacuum. Removing the vacuum takes the power booster out of the system and the pedal will be very hard and you will need both feet on the brake pedal to stop the car if the vacuum is lost while your driving the car. Sounds like the booster is working OK, lets see what everyone thinks, PG.

 

Are you saying that the brakes became solid w/ the PB booster hose disconnected? If so, then it sounds like the booster is shot.

1942 10-2-2008 Edit: You beat me to the punch and probably know more about PB systems. I don't have PB so was just making a logical assumption. Would be interested in why taking the booster out of the equation makes the brakes less effective.

 

PG the more I thought about it the more I seem to agree that the power brake system seems to be working. It was easy to press the pedal when it's connected much more difficult when its not. Which I'm up for more opinions but I'm thankful if it's not the PB because that thing looks like a nightmare to pull out, getting to those nuts above the pedal was already giving me nightmares. I also tried pulling out the check valve with the engine off, you could hear air being sucked in?/out? which makes me think the vacuum is working...

 

Is the check valve installed in the correct orientation?

 

The power brake booster is working. You either have air in the hydraulic system or the master cylinder is bypassing internally.

 

The power brake booster is working. You either have air in the hydraulic system or the master cylinder is bypassing internally.