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My son went with the full Ridetech suspension kit with this brake kit.
His new bored 454’s big cam produces low vacuum. So the brakes work but are not working as well as they should. We’re thinking about going with a hydro-booster. The two that we’ve found to be the best are Hydratech and Hydrastop.
Some have suggested going with an electronic assisted vacuum booster. CCP has a better site but of course that doesn’t mean that they have a better product. The vacuum booster would be cheaper but I’m not sure how well they work. Any insights or suggestions would be welcome.
Last edited by JakeLucas; Aug 7, 2025 at 11:37 PM.
Leave them alone.
Seldom do boosters go bad.
Often a replacement will not fit the "finicky" C3.
Often the booster is cussed at trying to remove nut #4.
Seldom does a new the booster mate-up perfectly with the GM master cyl.
Often it's the check valve failed and not the booster itself.
So, back to your mechanics analysts:
Does the brake pedal go to the floor while engine is running or off.
My 496 had 10” at idle on the dyno.
Most booster manufacturers will say their boosters require 15” or more to function properly.
I ended up converting to manual brakes.
I got the same responses in a thread I posted about low vacuum.
Members would say their boosters worked fine with 9”-11” of vacuum.
I called the manufacturers back and their statements were un changing.
Many members run manual brakes because it’s how their car left the factory.
I would ask your mechanic to get a vacuum gauge and see exactly what vacuum the engine is pulling, then decide if you want manual brakes, install a new booster, leave in the old booster or maybe install an electric vacuum pump.
On my 66 Mustang project I had a good sized cam in the 306 SBF. I went with a hydro boost from Hydratech. Worked perfect. The brakes could put your nose up against the windshield if needed. But was easy modulate.
Pic.
Last edited by 71 Vert LS1; Aug 11, 2025 at 04:28 PM.
I used the same Tuff Stuff 2222NA Universal Power Brake Booster, 7 Inch Dual Diaphragm on my Ford 390 ....Call them with your Vacuum numbers and get an expert opinion. Made in the USA
The 7 inch diameter was critical in that application, along with low vacuum....don't remember what it was...and yes check all your vacuum lines. Too many to count.
He needs to bleed them again. The D-8 calipers have a known problem with the bleeder screw location on the rear calipers. They need to be unbolted and rotated so that the bleeder screw is at the top. If you don't do this, you will have soft brakes no matter what.
We decided to go with this. It gets great reviews. My buddy that owns a shop just put one on his dad’s truck. He said that it’s working great. Anyone else use one of these.? Way cheaper than the hydro-booster in regard to both parts and installation. We’ll see how it goes.
First thing I would recommend is to remove and cap the vacuum lines feeding the headlights and HVAC system. They are notorious for leaking on older cars. Then measure the vacuum. If it still has not improved much..... I would then think about adding a vacuum reservoir and/or vacuum pump. Lots of YouTube videos on sourcing a OEM quality pump from modern cars. Most of the OEM vacuum pumps are made by Hella. They can be bought new for about $200 or used for half that.
First thing I would recommend is to remove and cap the vacuum lines feeding the headlights and HVAC system. They are notorious for leaking on older cars. Then measure the vacuum. If it still has not improved much..... I would then think about adding a vacuum reservoir and/or vacuum pump. Lots of YouTube videos on sourcing a OEM quality pump from modern cars. Most of the OEM vacuum pumps are made by Hella. They can be bought new for about $200 or used for half that.
Thanks. Solid advice. No HVAC. Had to bypass the heater, bad core. Luckily we don’t need it too much in San Diego.
The vacuum lines were new when we bought it and they worked well. The big cam on the new 454 just is not making enough vacuum.
Best brake booster solution
