what do i need to know about hydro boost brakes?

[Soundguy]

ok. apaprently this 99 F450 I got has the hydro boost brakes.

what do i need to know vs 'standard' brakes in everything else I own

soundguy

 

[schmism]

beats me

But my 85 chevy C30 has the same thing.... power stearing pump runs a line up through the master cylinder...

the lack of vacuum hoses on this thing is mind blowing....

 

[irvingj]

Found this via Google; apparently this is a system originally designed for the Hot Rod industry, but later adapted to OEM use. Apparently, "Hydratech Braking Systems" currently owned by Robert Bosch Corporation:

Commonly referred to as "hydrobooster or hydravac" over the years, a high performance hydraulic brake assist booster is a powerful alternative to a vacuum assist type booster. This type of assist unit uses the hydraulic pressure from the power steering system to provide a potent brake pedal assist. Just to name a few, there are a number of Original Equipment Manufactures that are using these styles of units on their vehicles:
-'96 and newer Cobras and all V8 Mustangs (though a much less powerful version!)
-Most 2500 and 3500 Series GMC / Chevy Trucks
-Dodge Ram equipped with Cummins Turbo Diesel
-Ford SuperDuty Series Trucks
-All Hummers - including the H2

 

[some zilch]

my '97 k3500 has hydroboost, and it stops on a dime (even with a non-brake trailer and 3 atvs). it is soooo much better than my older cummins/dodges. they are the best brakes ive ever had aside from air brakes.

 

[czechsonofagun]

The jeepers industry adopted it while ago:

Hydroboost Brake Conversion - 1

• Hydroboost Conversion » FAQ

 

[Bird]

The 1989 Chevy 3/4 ton extended cab dually that we had to tow our fifth-wheel is the only vehicle I've owned with hydroboost. As far as the operation, you won't notice any difference from the driver's seat, but it does provide good braking.

I've forgotten the year model, but some Buicks in the 1980s also had that. In 1991 when I was working in my brother's garage in Anchorage, I had a customer come in and wanted me to order him a complete new unit for his Buick. His worked, but he said he was "restoring" the car and wanted a new one. If I remember right, it was about $1,100, he paid me in advance, and I had the new one within a week. And then for 6 weeks or so, I didn't hear from the guy (and had no contact information). If it hadn't been completely paid for in advance, I'd have probably sent it back, but then after a couple of months, he showed up to get it; said he'd been called away on his job out in the wilderness and just got back.:laughing:

 

[Renze]

The VW inline 5 TDI in my Volvo has a common VW problem: the brake vacuum pump starts knocking after 50.000 km because the spring that returns the piston, gets sloppy. The effect is a knocking sound, eventually sounding like there is a connecting rod bearing shell missing.
If they used this hydroboost, they could do away with those silly vacuum pumps on Diesels, making the brake system think a gasser is attached..

 

[Highbeam]

It is a great system that is at least as dependable as the traditional vacuum system. All you need to know is that if you lose engine power, or blow a steering line, you will immediately also lose brake power. You will still have manual brakes but no power assist.

I really like the firm brakes on the super duty compared to my the vacuum powered brakes on my previous chevy products.

 

[ModMech]

All GM "G" and "P"s had it too as well as many '70s and '80s wagons. Should provide at least 5 assisted brake applications even with a disabled engine.

 

[rjkobbeman]

Years ago my dad had a 1981 K30 (one ton 4x4) with a 454 and the hydro boost brakes. Don't know how new the implementation was with Chevy, but it really sucked. The idea is really cool and we saw no reason why it should work OK... but we hated it.

I imagine this was relatively new and Chevy and hadn't got the bugs worked out yet.

When I say it sucked, I mean you couldn't steer at low RPMs. Either the power steering pump wasn't big enough or the pulley size was wrong. The pump obviously was not efficient enough at low RPMs (especially idle) to operate both the brakes and power steering. Navigating a parking space when you foot is on the brake while steering was difficult. (We had an automatic tranny.)

Often, we had to touch the gas to keep everything working.

Haven't had a hydro boost since then. (Not because of our experience, just never had another one.) Glad to see they actually work good now! No reason why they shouldn't.