Lets talk Hydro boost vs vacuume boost

[MadOgre]

Yep exception is diesel. Any diesel 1/2, 3/4 or 1 ton diesels have hydro boost.

 

[HotRodPC]

You might have trouble finding a 1/2 ton truck to use for an example. Hydroboost brakes were normally only supplied as OEM equipment on 1 ton trucks.

If you stay below 1987 the master should accept standard (SAE/"A") brake line fittings. You might not even have to change your current lines - but they may have to be reversed front to back. See the images below.

A cooler isn't necessary, but can easily be added later - if you find you need it.

As long as they are in good shape, your current brake lines will handle the pressure. The brake lines supplied with HB assist were identical to vacuum assist.


Couple of schematics:

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An 86 K20 with vacuum boost:

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And an 86 K30 with hydroboost:

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I've had an 80 C1500 2wd 1/2 ton with Hydro Boost, originally an Olds 5.7 Diesel, and my 85 4x4 K10 is Hydro Boost to this day, it was originally a 6.2 Diesel. All diesels got Hydroboost.

 

[Smith]

Now Im debating if I should go junkyard shoppign or just buy new. Would be the pits to get a hydroboost and master cylinder fromt he junk yard, bleed everything, put it in place and find one or the other is shot

Looks like I can get an ACDelco Hydroboost for $144 from rockauto plust a $40 core and a master Cylinder for $25

 

[bluex]

You can get a rebuild kit for the hydrobooster for about $30. Usually it's only a few seals that need replacing an it doesn't look too be to hard to accomplish.

 

[CSFJ]

After reading this thread, I'm kinda kicking myself in the a$$ for not getting the hydroboost from a truck I helped part out over the summer. It was a big score for me at the time,(sm465 2wd, hydro bell housing/slave and master cylinders, pedal assy, steering column, new 12" clutch and pressure plate, flywheel, and a fuel tank). Had the chance to get the hydroboost system too,but passed it up. Really wish I would have grabbed it after reading this.

 

[HotRodPC]

Live and Learn, you'll get the next one the next time the opportunity arises. I myself think I threw one away that needed a rebuild. I may have save it for a core. Don't remember for sure now. I got it from an 80 C10 Diesel truck.

 

[Smith]

Anybody know if this is the Pedal I want for my 84 to convert to Hydroboost?

 

[Smith]

http://www.gmpartsdirect.com/results.cfm?singlepart=1&partnumber=15906961

 

[Smith]

or does anyone have a hydroboost pedal lol

 

[skysurfer]

Where did you get that part number from? Google says it's for 1999-2011 vehicles. I looked at my hb pedal but there's no number on it. Figures, my old vac pedal has the number stamped on it plain as day but that doesn't do you any good.

 

[Smith]

Where did you get that part number from? Google says it's for 1999-2011 vehicles. I looked at my hb pedal but there's no number on it. Figures, my old vac pedal has the number stamped on it plain as day but that doesn't do you any good.

google and yea after more searching i just found the same as you. Would love to find a PN for the damn Hydroboost or one out of a wrecked truck

 

[Smith]

Yep, the pin that the pushrod attaches to is in a different position. I thought changing the pedal was going to be a pain but it was much easier than I expected.

couldnt that pin on the pedal be cut and re welded at the appropriate position? Or cut and a small piece of round stuck be welded on? Also wonder about using a press to modify the shape of the pedal. Mor curious about the cutting and welded though

 

[CSFJ]

I've got a pedal assembly off a hydroboost that's going in my truck. I can check for a part # when I get home from work. The pedal came out of a '89 1 ton with the 465.

 

[skysurfer]

couldnt that pin on the pedal be cut and re welded at the appropriate position? Or cut and a small piece of round stuck be welded on? Also wonder about using a press to modify the shape of the pedal. Mor curious about the cutting and welded though

Never heard of that being done but I guess it's possible. Only snag is to get it exactly right you would need a hydroboost pedal to compare to... and if you have that you wouldn't need the modded one.

Here's a pic showing the two, the hb is the one with the rubber.

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[Smith]

I've got a pedal assembly off a hydroboost that's going in my truck. I can check for a part # when I get home from work. The pedal came out of a '89 1 ton with the 465.

Your 89 would not be a square correct?