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'89 Blazer LS swapped DD/Adventure Rig

Hydroboost

I need some info on Hydroboost. I have read until i can read no more.

I am converting to hydroboost since the clutch pedals that are on the way are from a hyroboost truck, and from what i have read its a much superior system.

I pulled a hydroboost booster today from a 1985 C20 6.2 diesel for a core. I ordered the same unit to go in my blazer, is this the correct unit i need to perform the best? I have done my research and rock-auto has a different listing for diesel and gas hydroboost units, does anyone know the difference?

The truck that I pulled the unit from had a cast iron master cylinder, is there a plastic reservoir type master out there that will work and have the correct fittings?:dunno:

Do I need a hydroboost proportioning valve?
 
I have only owned factory equipped hydroboost setups. My current truck, 89 R3500 crew cab with TBI350, came with the aluminum master cylinder with plastic reservoir. If that's the reservoir you like you should be able to use that for an application reference.

The hydroboost unit I have now I had rebuilt and given a "high-flow" treatment by VancoPBS on Pirate4x4. That was done when I had my 84 K5 and it was a hydroboost I had pulled from another truck that I don't remember what it was. So my current hydroboost has been in 3 different vehicles which leads me to believe there's not much difference despite different part number listings.

Since I've only had factory equipped hydroboost trucks, I've never messed with proportioning valves.

I don't think there's any one hydroboost better than another.
 
I have only owned factory equipped hydroboost setups. My current truck, 89 R3500 crew cab with TBI350, came with the aluminum master cylinder with plastic reservoir. If that's the reservoir you like you should be able to use that for an application reference.

The hydroboost unit I have now I had rebuilt and given a "high-flow" treatment by VancoPBS on Pirate4x4. That was done when I had my 84 K5 and it was a hydroboost I had pulled from another truck that I don't remember what it was. So my current hydroboost has been in 3 different vehicles which leads me to believe there's not much difference despite different part number listings.

Since I've only had factory equipped hydroboost trucks, I've never messed with proportioning valves.

I don't think there's any one hydroboost better than another.

Did your R3500 come with hydroboost?

FWIW, I once tried to swap a plastic/aluminum vacuum MC from an '82 C20 parts truck onto my '83 diesel. It was not close to fitting where the cast iron MC had been. Larger diameter opening and wrong lug spacing. So it is certainly possible to find configurations that don't work.

The proportioning valve setting should be a function of MC and SC geometries. For a given MC I don't think the type of booster can make a difference in the front/rear proportioning ratio. :dunno:
 
Did your R3500 come with hydroboost?

Correct.

The hydroboost in the 89 worked with the cast iron unit that was in my 84 K5 too. I like the aluminum/plastic versions better myself.
 
Correct.

The hydroboost in the 89 worked with the cast iron unit that was in my 84 K5 too. I like the aluminum/plastic versions better myself.
I do too, I have searched all day for your version and have been unable to find it.

Oh well, I will paint the cast iron one up nice and let it go.
 
Parts are here!! I will post up everything for anyone interested.

Now waiting on pedals and transmission to show up, but that'll give me some time to get the hydroboost done.
 
Yeah, I read that you were switching to hydroboost, I just wan't sure if you got some hydraulic pedals or not.

Martin
 
Update

Update :

The column is out and the auto pedals are out. I will say, everyone makes that out to be a way harder job than what it is, I took me MAYBE an hour and a half. But that's a good thing, nice when things work out well. :D

All my parts showed up, here's a list of what I'm using :

2004 Silverado 4.8L
Flywheel- Sachs NFW1050
Clutch Kit- LUK 04205
Slave Cylinder- LUK LSC326
Flywheel bolts - ARP 3302802
Pressure Plate bolts - ARP 1342201

85-87 (91) Pickup, Blazer, Suburban
Master Cylinder - LUK LMC128

Thanks to those of you that have guided me through figuring out what I needed! Much appreciated!


My transmission should show up by the end of the week, fingers crossed. Once I get that in I can locate the shift tower and cut the transmission tunnel, I am dreading this...
 
I took the seat out, and that made it 100x more comfortable.

Some people were referring to it as the worst job they've ever done, I'm like wtf??
 
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Got the pedals in!

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fyi do not use the center dimple to drill the hole for the master cylinder body, it will not be correct. I drilled the mounting holes and then made a template to locate the center hole.

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I got a question

I know this connector is for the cruise control switch, but I can't find the other end. Anyone know where it might be hiding?

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And this one is around the fuse block and ties into the upper dash harness, anyone know where it goes?
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Awesome! :woot:


Your cruise control plug looks different from mine (though mine did have a similar-looking 3-wire resin board acting as the connector, it was encased in a plastic plug). You're holding the truck end, right? And it plugs into a small plastic box attached to the speedometer. Or is your setup different?


Overall, you seem to have a whole lot more wires under there than my non-OBD diesel trucks have. :dunno:
 
Awesome! :woot:


Your cruise control plug looks different from mine (though mine did have a similar-looking 3-wire resin board acting as the connector, it was encased in a plastic plug). You're holding the truck end, right? And it plugs into a small plastic box attached to the speedometer. Or is your setup different?


Overall, you seem to have a whole lot more wires under there than my non-OBD diesel trucks have. :dunno:
On the cruise connector I was holding the column end... no clue where the truck end is hiding... I do know it was plugged into another connector and not into a box.

As for the other connector I have no effing clue lol
 
Figured it out after staring at it for a half hour.

The black connector and the cruise connector go together, if you look closely there is a locking clip on the black connector and a matching notch in the board of the cruise connector.


As a general update, i got quite a bit done today:

Reassembled the newly painted pedals with new bushings

Installed pedals

Figured out holes/mounted master cylinder

Installed column

Installed hydroboost

Swapped power steering pump


Everything went together nicely so I am happy about that. I hope to have this thing rolling by the end of the week.
 
Did the tranny and stuff show up yet?

Pedals are a pain, but I think most people make it harder on themselves by only trying to remove the minimum of other crap. I didn't find it a horrible job, but i did the same as you and pulled the seat immediately...
 
Did the tranny and stuff show up yet?

Pedals are a pain, but I think most people make it harder on themselves by only trying to remove the minimum of other crap. I didn't find it a horrible job, but i did the same as you and pulled the seat immediately...
I should have the transmission in the next day or two, the guy that picked it up for me was doing me a favor so I don't have much leverage in this situation.

But needless to say, the blazer will be ready to receive it when it does show up.

All I have left to do is :

Bolt up flywheel

Install pilot bushing

Install/align pressure plate

Plumb return lines for hydro boost

Bench bleed brake and clutch master cylinder

Cut hole in trans tunnel

Pray like hell that the drive shafts/trans crossmember don't have to move.
 
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