What is this?

[Flat 67]

Why is it that my brake master cylinder does not have a diaghram? Instead it has some hoses connecting it to the power steering pump. Is this a sought after feature? Can a regular diaghram be installed? Oh, BTW, the pic is from a 78 C-30. Thanks.........

[70short/step]

It is a hydro-booster. It runs off of fluid from the power steering. Some like it because it isnt as bulky as the power booster. Also it came on the heavier duty trucks.

[SanitysBane]

And it also aplies a crap load more fluid presure, keep it.

[Flat 67]

Thanks for the response. It is amazing the amount of info that can be gotten out of this forum.......

[Russell]

Yep, hang onto that! Far superior braking system to a vaccum booster

Most newer trucks utilize them

[SanitysBane]

Plus you can throw people threw your windsheid at will...

[Lynx]

Usually came on heavy duty trucks and Diesels as they don’t produce vacuum

[special-K]

That`s it,you don`t need no stinkin`vacuum.It`s a great system.

[Jim85IROC]

The one thing that I HATE about the hydro-boost brake system is that if your power steering pump fails or a line bursts, you lose your brakes completely. Unlike a vacuum boost system that just makes it much harder to apply force when it fails, the hydroboost causes the pedal to go right to the floor with no effect when you lose power steering fluid pressure. Not cool.

[SanitysBane]

Not on my setup.

[trixter99]

I've always appreciated how they seep fluid and generally just look like a dogs breakfast.

[Russell]

Originally Posted by Jim85IROC

The one thing that I HATE about the hydro-boost brake system is that if your power steering pump fails or a line bursts, you lose your brakes completely. Unlike a vacuum boost system that just makes it much harder to apply force when it fails, the hydroboost causes the pedal to go right to the floor with no effect when you lose power steering fluid pressure. Not cool.

Not true!

My 80 has hydroboost, and even if I turn the truck off, I still have 1 useage of the boost power, just like vaccum boosted brakes, and if I use that, I still have manual type brakes, just like a vaccum booster.

The two setups are nearly identical in their purpose, and both work much the same way, just that one uses vaccum for boosting, the other uses fluid pressure for boosting

Maybe the older setups don't have the little bronze canister that holds pressure for use if you loose a hose, throw a belt, or stall the truck, but the new ones certainly do!

BTW -- My 80's booster looks real nice too! I sandblasted it, painted it gloss black, and polished the lines. No seepage here

[Jim85IROC]

Well, I've had 2 people disagree with me, but more than once when my power steering pump was on it's way out, I rolled right through an intersection because my foot went to the floor and I had no brake pedal. I almost got killed one of those times, so it's still pretty clear in my memory. For that period of time before I replaced the pump, instead of just having a ridiculously hard pedal like I get with a failed vacuum booster, my pedal went right to the floor with no braking.

[Russell]

Originally Posted by Jim85IROC

Well, I've had 2 people disagree with me, but more than once when my power steering pump was on it's way out, I rolled right through an intersection because my foot went to the floor and I had no brake pedal. I almost got killed one of those times, so it's still pretty clear in my memory. For that period of time before I replaced the pump, instead of just having a ridiculously hard pedal like I get with a failed vacuum booster, my pedal went right to the floor with no braking.

Wow, something was not right with your hydroboost unit! Most newer Chevy trucks use them, as far as I am aware (less some half tons) and I haven't seen any of them rolling through the intersection, LOL

But yeah, I'm glad you are still with us, and I can understand your dis-taste for the system having had it fail on you more than once!

[Lynx]

Russell is corect, Either older systems were diffrernt or there is somthing wrong with your master cylinder/hydroboost. Modern Safety laws state that you must have a physical backup to a booster. All the booster is doing is boosting the force that you are applying to the master cylinder thus applying the brakes. (not sure how all this works with brake by wire systems but thats another story) Ill ask my instructor this afternoon and see what he says.

[Flat 67]

I sure appreciate all the input.......You guys are really thorough with your answers.

[79BIG10]

Originally Posted by Jim85IROC

Well, I've had 2 people disagree with me, but more than once when my power steering pump was on it's way out, I rolled right through an intersection because my foot went to the floor and I had no brake pedal. I almost got killed one of those times, so it's still pretty clear in my memory. For that period of time before I replaced the pump, instead of just having a ridiculously hard pedal like I get with a failed vacuum booster, my pedal went right to the floor with no braking.

I'm thinking that your check valve at the booster is bad. If the vacuum is pulling then it's creating pressure. But if the truck is not running then the check valve cuts off and keeps the pressure built up in the booster. But with a bad valve it will leak out and let the air back into the system.

To replace just take it off the booster itself and from the hose and clamp. You can get them at the HELP section at the local parts store.

[SanitysBane]

I work at a chevrolet dealership and all taho, subs, and anything above a 1/2 ton truck uses the hyrdo boost.

[Bri87swb]

This seems like a superior alternative to the vacuum brake system. Would it be fairly simple to make the swap?

[NO LONGER DISTURBED KONCEPTZ]

My buddy put that on his 69 1 ton and it stops great. Even with a load on it.

[SanitysBane]

It is very very easy to make the swap. I did it to my 83 1/2 ton about a month back or so. Let me know if you would like any information and or pictures.