October 2026 Brake Tech Talk... Soft brake pedal? See below...

October 2026

Newsletter and Brake Tech Talk... Soft brake pedal? See below...

It's that time of year, shows and cruises are over. Time to remove your booster and get it restored.

TIME FOR BOOSTER OR MASTER RESTORATION?

It always gets interesting this time of year. Our team starts getting phone calls; my booster made it through the last cruise of the year, now it needs help, or it was a scary ride home. What do I do, the booster died, or the master has given up, I have heard lots of stories. During these times, I encourage our customers to get the booster and/or master sent in for restoration or rebuild. Now the pressure is off, now you can pull both the booster and master and have them rebuilt or restored like new again. Call or Email us if you have any questions on how to get the booster and/or master to us. 503-238-8882 or sales@powerbrakebooster.com. Pictured below is a restored booster and master.

PBBE -"Brake Tech Talk"

 Brake Pedal Soft After Changing Parts?

 Insight- By Booster Mark

Working on a vintage car? Aww.. The pedal is soft after replacing a master cylinder, wheel cylinder, or caliper. What Happened?

I get a call at least once a day asking for advice on the fix after changing out parts in a brake system. I got air stuck in the system here is the advice I give them. Gravity and patience.

First thing-never push the brake pedal to the floor during any of these processes. It will damage the brake booster. During the first part of the process, don’t even use the brake pedal at all. I always remind folks, better to be safe than sorry. We see all the time where people ignore this. When we open a booster up, it talks to us, we see broken hub parts, bent pedal rods internally, the tell tales signs are there for sure.

First, if the master is being or has been changed out, be sure to bench bleed it if it has not been, no exception. Cannot express that enough. With that said, let’s go down some simple but very effective processes to get the trapped air out of your system. Make sure your master fluid bowel is full, be sure to have at least 4 quarts of fluid available. Keep checking it through this process. Do not let it go empty or you will be starting over. Do not step on the brake pedal during this process. Gravity will do all the pushing. Lift and support all four wheels off the ground, (be sure to have a flat pan on the floor to catch any fluid). Open all four zerk fittings. One at each wheel, now let gravity be your friend. Are you getting a constant drip at all four corners? Chances are you are not. If you are, close off the zerks that are flowing. Leave the others open. Continue to have gravity do the work for you. Continue to close each zerk until fluid has a consistent drip out each zerk. All four should now have had fluid running out of it. Note: it can take 1-2 hours for some lines to get the trapped air to flow out.

Caliper special note: if you are not getting fluid coming out of a caliper, don't worry yet, calipers can trap air on the internal porting of the casting. Close all zerks, press down the pedal, open the caliper zerk, pedal goes down, close it, repeat over and over until fluid gets moving.

Make sure all four zerks are closed. Go to the caliper that has no fluid. Pump the pedal softly (ENGINE MUST BE OFF) open zerk, pedal goes down, close zerk, repeat until there is fluid. Do this with any caliper that is not pumping up. This may take 2-3 quarts to push all the air out.

Next, if for some reason 1 or 2 lines or calipers, or wheel cylinders don’t have fluid flowing by now, that is a problem, they all should. Follow the brake lines up to the next fitting, crack it, are you getting fluid now? If not, keep going up the line, eventually you will get to a point where fluid is flowing. That is a sign of a clog in the line, a collapsed hose or hard line, bad part; replace, then repeat the process. You should now have fluid to all corners.

Now and only now are you ready to bleed your system. Yes, you are just getting started, but now you will have success. Now you have fluid dripping consistently on all for corners, close all zerks. Pedal should have some resistance but still be soft. Now you can start the bleeding process that everyone is familiar with, start with the right rear, pump pedal soft and not to the floor open and let fluid out. Pedal goes down a bit, close, repeat until nice flow, then do left rear, right front, left front, following the same process.

This process works with any of your vintage cars.

Each month I am going to address brake systems, including boosters, masters, calipers, etc. Let me know if there is an issue that comes up regarding your brake project, we will see what we can do to assist you. We love sharing our knowledge and get excited when your project comes together.

______________________________________________________________________________

______________________________________________________________________________

OUR PBBE True Vintage Bore Master cylinder line has sure been a hit. The four master cylinders we have released include, cougar/mustang, mopar 1960-1970 dual port, GM 1967-1977 dual port and last GM single port old school 1955-1966

_______________________________________________________________________________

A friendly reminder- be sure to package your boosters safely. Go to our website under "shipping" for guidance on best practices to ship your booster. Don't let this happen to you! 

Discover More

For the DYI - The Parts You Need

We have been adding more booster associated parts to our website shop. We also just added a search bar so it's still being updated, but it will assist somewhat.

 As you may have seen, we are always adding to our PBBE SHOP for the folks that just need a part or want to restore a booster themselves. Are you looking for that hard to find part? We continue to add parts. We listen to your needs and respond to them. From making certain parts to putting together kits. Our desire is to help you restore your car by helping you with your braking needs. If you are looking for a certain part, let us know, we will see what we can add.

Talk Soon

Booster Mark n Team

mark@powerbrakebooster.com

503-238-8882

Contact Us