[Mr Anonymous]

Hydroboost? I wouldnt recommend it. Not only is the pedal feel really bad, your "assist" can be affected by something as dumb as the PS belt tension. I've also panic stopped a hydroboosted GMC crew cab that was pulling an open trailer with a car on it. I dont ever want to be in that situation again. EVER. An evasive maneuver combining heavy steering effort and heavy braking effort is a bad deal.

Not a fan of vacuum cans, for the same reasons as already mentioned.

I have more than one car with manual brakes, and one of them is a disc/drum street car. With the right combination of parts, the pedal feel and feedback is hard to beat in my opinion.

[Formulajones]

2 cars and 2 trucks here with hydroboost and never an issue. Love the pedal assist. Works as intended, rock solid pedal feel on all of them.

Used to run vacuum cannisters with "OK" results but still only good for about 2 stops when idling around a parking lot. Then tried electric vacuum pumps, got really tired of the noise they created.. Went through all that for years before throwing in the towel for hydroboost and now won't ever look back.

On a hot street car it's either going to be power brakes with hydroboost or a manual brake system. That's it.

[JLMounce]

Originally Posted by Mr Anonymous

Hydroboost? I wouldnt recommend it. Not only is the pedal feel really bad, your "assist" can be affected by something as dumb as the PS belt tension. I've also panic stopped a hydroboosted GMC crew cab that was pulling an open trailer with a car on it. I dont ever want to be in that situation again. EVER. An evasive maneuver combining heavy steering effort and heavy braking effort is a bad deal.

Not a fan of vacuum cans, for the same reasons as already mentioned.

I have more than one car with manual brakes, and one of them is a disc/drum street car. With the right combination of parts, the pedal feel and feedback is hard to beat in my opinion.

To play devil's advocate here, the brake sizing on those mid 90's chevy light and medium duty trucks/suv's was piss poor. Hyrdoboost isn't necessarily the issue as much as the fact that GM put brake rotors and calipers on those vehicles that were originally on late 60's to early 70's cars that weighed 1500-2000 lbs less and weren't towing trailers.

Hydroboost is one part of the brake system, it can't make up for extremely undersized brakes with sheer line pressure.

[Formulajones]

When it comes to trucks, I've only had hydroboost on the 3/4 ton and 1 ton trucks we had. All of which have massive brakes on them.

My 79 1 ton had it, and up until the day I sold it a few years ago, the factory system was still working flawless. I owned that truck 25 years and never had a single issue with it.

[65madgoat]

Had hydroboost, but as mentioned a properly set up manual brake system is the way to go here. Cleaner, simpler, less to go wrong and not expensive.

[Mr Anonymous]

Originally Posted by JLMounce

Hydroboost is one part of the brake system, it can't make up for extremely undersized brakes with sheer line pressure.

No argument from me.

[Schurkey]

Originally Posted by JLMounce

To play devil's advocate here, the brake sizing on those mid 90's chevy light and medium duty trucks/suv's was piss poor. Hyrdoboost isn't necessarily the issue as much as the fact that GM put brake rotors and calipers on those vehicles that were originally on late 60's to early 70's cars that weighed 1500-2000 lbs less and weren't towing trailers.

Hydroboost is one part of the brake system, it can't make up for extremely undersized brakes with sheer line pressure.

The "big problems" with the GMT400 trucks were especially pronounced on the 1500 series; but those were by far the most-produced. There were enormously fewer 2500 and 3500 series trucks made compared to the 1500, and the heavier-series trucks also had much better brakes.

The 1500s had a crappy rear axle originally designed for compact and intermediate-sized cars. GM had no business putting it under a full-size pickup. That axle was almost universally equipped with 254mm (10") leading-trailing shoe drum brakes that require the park brake to be used in order to maintain shoe adjustment. Since nobody uses the park brake, the shoes are perpetually far from proper adjustment. Making things even worse, the front shoe on each side does all the forward braking. Which is why the front shoe will be worn-out long before the rear shoe--which does the majority of braking in reverse.

The first few years of that truck series, the regular-cab 1500s got a miniscule power booster, thin rotors, small-bore master cylinder, and tiny caliper pistons. Even GM acknowledged that the JN3 brakes were under-powered, in the early '90s they increased the braking power to JN/JB5 series brakes--what had come on the extended cab 1500s all along. But they still had the horse-crap leading/trailing shoe rears.

A rear-axle swap that replaces the junk 8.5" ring gear, 10-bolt axle with the 9.5" semi-floating 14-bolt cover axle also upgrades the rear brakes to proper 11.x Duo-Servo drum brakes where both shoes stop the vehicle.

Don't get me started on folks who think they can bleed ABS brakes on the post-1990 GMT400 trucks without using a scan tool to chatter the solenoids.

[lust4speed]

I had a 3/4 ton truck engine die going down the freeway with the hydroboost system with me driving and doubt the wife could have got the truck stopped quickly and safely. It was a handful.

We've had three club members recently that followed the yellow brick road to more radical cams and all three are very happy swapping to manual brakes. Always the same pedal effort on each stop regardless of what the engine is doing. The drag car with manual brakes and the 4-wheel disks can be locked up pretty easy and that's a small disc system.

[Formulajones]

Power steering is the same way. If the car dies, it's extremely difficult to even steer the car, much more so than a manual steer car. Not many people can deal with that either. I know my wife couldn't, but the cars she drives has to have power steering. That's just the chances we have to deal with on most any car. Been that way forever.

I do like manual brakes, and one car in the stable still has them. While it could use an upgrade (4 wheel drum) to some disc up front, that car will stay manual brakes and manual steering. I do like the simplicity of one fan belt and not much else under the hood.

[Schurkey]

If your hydroboost dies when the engine stalls, you need a new accumulator. There should be enough stored pressure in the accumulator for a couple of additional stops. The analogy is to a vacuum booster that stores enough vacuum for a couple of extra stops if the engine stalls.

Similarly, if you have heavy demand for both the hydroboost and power steering, the hydroboost should be unaffected because the accumulator has stored energy.

[Formulajones]

Originally Posted by Schurkey

If your hydroboost dies when the engine stalls, you need a new accumulator. There should be enough stored pressure in the accumulator for a couple of additional stops. The analogy is to a vacuum booster that stores enough vacuum for a couple of extra stops if the engine stalls.

Similarly, if you have heavy demand for both the hydroboost and power steering, the hydroboost should be unaffected because the accumulator has stored energy.

Yes and as an example of that, I've pushed the car outside on occasion, on a downward slope, and it still has power assisted brakes without the engine running.

[blueghoast]

Originally Posted by caddor38

I was curious to those who have a larger cam with power assisted brakes what you use for Vacuum assistance. Is there a cam profile lift, durations? that determines when to move from a Vacuum can to a pump assisted vacuum? I have the Competition Cam 308R Solid Roller with 575 lift 262 duration and have already installed a Vacuum cansiter, but was a little worried to the affects of stop light to stop light braking etc.

I have that same cam in a build I just did for my 57-Wagon project
I'll let you know when it comes together, Probily be to late though

GT