On the way to work this morning my brake booster failed, so drove back home and parked it.  It's a '75 2+2, so it's the larger 10.5" brake booster.

I will most likely either send mine out to boosterdeweyexchange.com or pick one up from Motorsports Auto.  Any reason to pick one over the other?

Is it possible to remove/replace the brake booster with out affecting/introducing air to the brake lines?  The FSM is vague and searching online for a couple hours didn't give a clear answer.   I do not have access to anywhere close by I can bleed brakes, so will have to farm out the work if that’s the case.

Normally you can pull the master cylinder far enough away from the booster to get the booster out. The lines will flex or bend enough to do this with out unhooking them.

MSA is using a rebuilder I'm sure. I think price would be my first consideration. Also your master cylinder is most likely leaking into the booster causing the failure. That would require replacement and bleeding if it's the case. There will be a lot of corrosion at the end of the master cylinder and many times you can pour excess brake fluid out of the booster. The fluid destroys the internal diaphragm

Ok then, 

I'll source a master cylinder as well and have a local shop do the install.  My brake booster looks beat and old, probably original.  Master cylinder looks way to shiny to be original.

Thanks for the info Patcon.

You could do that or try pulling the booster first. If the master isn't corroded on the rear end then you could just replace the booster and move on. That would be cheaper and you could do all the labor. If you have questions post up some pictures

https://www.yelp.com/biz/power-brake-exchange-san-jose

these guys do a very nice job rebuilding mine; i think they powder coat for an extra $15? $135 out the door, but im local. I think they have a so-cal spot.

I hung my masters in place from my garage ceiling with some nylon cord then removed/replaced the booster. Easy enough but the nuts above the brake pedal were a real pain to get back on. Took a couple of hours but saved some dough ray me.

Got my rebuilt booster from amazon.com, painted it satin black and glued the Bendix red sticker onto the new one. Looks original too. Good luck!

You can remove the screw/bolt from the junction blocks of the hydraulic lines down on the fender well and frame rail.  That will give you a lot more flex in the lines to the MC and let you leave everything connected.  You might find fluid leaking from the back of the MC though once you get it apart.  That's the common reason the booster fails.  Don't let any fluid leak from the booster on to your paint.  It will stain it, or worse.

 

Thanks for the info everyone.  I called up Booster Dewey Exchange and Power Brake exchange.  Dewey has all the parts for a rebuild but the diaphragm.  So going to my booster to the Power Brake Exchange SoCal location. 

Sprayed some Kroil on the bolts and did a deeper inspection.  Going to get a new Brake Master Cylinder.  Looks like the only choices are Cardone, Beck/Arnley, or Centric. Any reason to pick one over the others? 

This doesn't seem like too hard of a job so I will probably head to the closed down toys-r-us parking lot that's not very far and do the job there.  Replaced my fuel pump there a couple years back and had no problems.  Worst case scenario I have AAA.

 

8 minutes ago, 2377kN said:

Sprayed some Kroil on the bolts and did a deeper inspection.  Going to get a new Brake Master Cylinder.  Looks like the only choices are Cardone, Beck/Arnley, or Centric. Any reason to pick one over the others? 

Whichever you get take it apart and clean the bores out before using.  Sometimes they leave honing grit inside that will kill the seals pretty fast.  Reman quality.

i usually go with Beck, i used their master and clutch cylinder, no complaints here.

Got the booster out over the weekend and sent it off to be rebuilt.  I hope to have it back by Memorial Day Weekend.

The master cylinder was not leaking any fluid, but I don't trust it anymore.  Going to replace it.

Also ordered new master and slave clutch cylinders.  Gonna head to the DIY garage in Baldwin Hills, CA to do that in a couple weeks.

 

Thanks everyone for the info,  I'll update when the job is complete.

Update:

Got the brake booster back from the Power Brake Exchange SoCal Location.  Cost was 120 for the rebuild and 15 for shipping.

Last weekend I got it back in the car and then replaced the Master Cylinder.  Ended up getting one from Courtesy Nissan in TX.  Definitely more expensive than the ones from Rock Auto.  Also got a clutch master and slave to replace in a couple of weeks.  Installed speed bleeders, they are a nice upgrade.

Ran into only one snag.  I removed the drivers seat to have easier access to put the brake pedal clevis and pin back.  When putting the seat back one of the blots snapped off.  Was just past finger tight at that point.  Weird.  Was able to drill into it and back it out pretty easily.  Replaced all the seat bolts.

Made sure not to drop the reaction disc.  But I think I need to adjust the pushrod about 3mm out.  

I never noticed til now after paying attention how different the brake pedal feels in different cars.  In my household there is the 280z 2+2 (10” booster), a 2005 Jeep Wrangler Unlimited, and a 2018 Hyundai Tucson.  The 280z has the heaviest feel, the Hyundai the lightest.

Going to go though the rest of the braking system next.  Rotors, Calipers, Drums, Wheel Cylinders, and Hoses.  Keeping everything stock.  There’s plenty of stopping power for my cruising.