HydroBooster Rooster

[swissarmychainsaw]

I'm looking to add hydroboost to my Rig. The brakes just suck on this thing, I'm getting it sorted out now, but it seems that adding Hydroboost is a no-brainer.

My Truck: 1973 Suburban K10 350/350

Donor: 1999 Chevy Van 3500 (Express?)

I think this swap is pretty much:

* Add Booster and Master to firewall
* Fabricate a mounting plate (if needed)
* Get adapter for brake pedal
* Make custom lines from/to Booster to Stock Saginaw steering gear
Leave some skid marks!

Who has done this and has stuff to add?

Much appreciated!
--Nick

[nonstop]

I've done it. I pulled a set up out of a truck at a junkyard. It would probably be the easiest way for you. The square body parts are guaranteed to fit, and if you need hoses, you can get them at the parts store instead of having them custom made. You will need the hydroboost brake pedal and the power steering pump as well.

Mine is an 85 GMC and I am running the set up off a mid 80's truck with a c3500hd master with 4 wheel discs. It would lock up 36 inch tires at the drop of a hat.

[swissarmychainsaw]

Thanks! Any reason I can't use the stock Steering gear box?

If I use the 1999 gear box I would also need a pump, as my uses the older fittings (non-metric SAE)

[hatzie]

The later steering boxes, PS pumps, and Hydroboost had O-ring pressure fittings. You can make hybrid hoses, use the gearbox off an 84ish-86 CK or RV series truck, or find adapter fittings.

If you change the steering box you'll need the O-ring pressure fitting on the steering pump. You can Tee the return lines but the hydroboost PS tank is cleaner.

Any way you do it you'll need a squarebody Hydroboost bracket.

[swissarmychainsaw]

Do I need the special socket to remove the Hydroboost unit from the Donor?

Or is that only needed once the HB unit is off the vehicle?

Planning on picking up the unit from the Donor Van on Friday.
thanks

[hatzie]

Regular hand tools to take it off the van.

The socket is for the nut that holds the boost unit to the bracket.
You will want the pushrod.

Captainfab makes mounting plates and the special socket. http://67-72chevytrucks.com/vboard/s...d.php?t=347480

[swissarmychainsaw]

Well, a year later and I'm actually *doing* this upgrade.

Parts I have for this:
1983 Hydroboost from a K30
Power steering pump from the K30 + the three hoses.

1984 K20 Steering gearbox (this should use the same fittings as the 83, so I don't have to get hoses made)

I ended up getting the Hydroboost unit, and power steering pump and hoses from a 1983 K30 Chevy Dually.

I'm really happy to say the Hydroboost mounted to the firewall on my 73 Suburban with zero modifications. I had to remove two studs from the hydroboost mount flange, but it's an exact bolt on to the firewall!

K30 Power Steering pump with reservoir: looks like the bracket that mounts the Powersteering Pump is broken. It's missing the tab where it should mount to the head.
It also looks like the 1 ton Pump bracket is different (the position of the pump to the motor is different).
Any tips on this?

I have the stock 73 power steering pump with bracket, an 1984 3/4 ton pump with bracket, and the 83 K30 pump with broken bracket.

Do I pull off the pulleys and use the original 73 bracket with the K30 pump?

Thanks for the help. I can't wait to have some brakes!

--Nick

[Half Assed]

Well IIRC the fittings are metric on the 80s trucks, so you will probably want to use the 80s pump.

And I also know saginaw pumps came with different bolt mounting patterns, but I couldn't tell you if they are the same between the 3 that you have. I guess you will have to remove the pulleys and check.

I was going to say you can use the hydroboost from the van, but then I saw the post is a year old... I used one from a late '90s 1 ton van on my truck. If you grind off the mounting bracket on the back of the vacuum booster it will bolt up directly to the van bracket. Then you just need to chop/weld the brake pushrod to length.

[swissarmychainsaw]

Thanks! I just checked and all the hoses I have mate, so the 83 Booster & pump are going to work with the 84 steering gear box (as far as the hoses go!).

I'm heading to the store to get a pulley puller right now.... and maybe a beer or two.

[mongocanfly]

I know you already tried your hoses but just so anybody else would know when I went LS my 81 hydroboost hoses fit the 2002 6.0 power steering pump with no issues..

[swissarmychainsaw]

That's great that GM put the same hoses on stuff, makes it way easier.

Damn, I forgot the beer!

Pulleys are off, here is what I found out:
All three pumps (73 K10, 83 k30, 84 k20) have compatible mounting brackets.

I put the K30 Hydroboost pump on the 84 K20 bracket, three bolts, all line up nicely. It fits on the motor too without hitting anything.

Feels like the bracket may be be perfectly straight. Any advice on pulley alignment?

the 73 K10 has a single pulley on the power steering pump so that is what I'll be putting on the 83 K30 pump spindle.

Anyone confused yet?

[mongocanfly]

Yep..

[abig84]

i dont know if you noticed yet but i swapped hydro to vacuum a few times in the past and the brake pedals are different. the brake pedal for the hydroboost had a bigger pin then the vacuum pedal. was no big deal for swapping my way as i just ground it down a bit youre going to end up with a big of slack where the booster meets the pedal as the pin should be smaller.

not that big of a deal but jut a heads up on something minor

[swissarmychainsaw]

Thanks for that it's a good point about the pedal. One downside of getting a "newer" unit is that you *have* to get the HB pedal as the mount point for the actuator shaft thing is in a different location. I was hoping that since my truck is a 73 and the donor was an 83 that I could use the original pedal.

As you pointed out, it looks like you can, but the size of the eye on the shaft is larger the my original 73.

I think I might have said "I'll deal with that later"!


The pulley tool I bought does not thread into the pump shaft (to install the pulley) So I'm off to the store to get that sorted...

[swissarmychainsaw]

One thing: I'm new to the hydraulic lines that have o-rings, can the o-rings be replaced separately, or do you have to get new lines? Meaning do they sell the o-rings at the parts place or can I buy a box of o-rings and see what fits, etc.

Second thing:
Do I need to swap the master cylinder? I'm sort of assuming that the original MC in the car now will work fine. I do have the K30 master from the donor, but no idea if it's good or not.
Was hoping to use the stock one and have one less system to deal with.

Thanks!
--Nick

[abig84]

the o-rings should come off. usually whenever we replaced a power steering pump, line or any other power steering part it comes with new o-rings. just need a small pick and just pick them off the line. i dont know if you can buy just the single o-rings anywhere. at work we just have a gigantic kit which of course is missing all the commons sized ones

[swissarmychainsaw]

This thread needs pics!



So here is where we are so far:

I bought an assortment of o-rings like this, and so far so good for replacing the squished ones in the steering lines (have not pressurized them yet)


Hydroboost
1983 K30 unit is a direct bolt in to the fire wall.
Pedal linage works ok, though the eye is a different size (HB is larger). No mods at all required. ( read somewhere that one is 1/2 and one is 9/16 )

Power steering Lines
*1983 K30 stock lines that came with the donor. No mods.

Pump Bracket
This one was tricky because I assumed they would all work.
Options were: 1973 original, 1983 K30 (broken), 1984 K20 (not the same!)
I tried the 84 but the pump would not mount up.
Pump Bracket: 1973 K10 original bracket
Notes:

Pump
1983 K30 from the donor.
Notes: This one has two return lines (from gearbox and from hydroboost); USE THIS, I have read that using a "T" for the return lines will give you issues.

Pulley:
Single pulley from the stock 73 K10

Gearbox
1984 Saginaw gear box.
I had this laying around and used it because all the lines are metric and bolt right in.
Notes: 73 K10 uses a different size input shaft (larger)
Mods required: The input shaft is a different size on my 73 K10 vs the 84 K20.
I bought a new rag joint that has the correct size. This was horrendously expensive! $46

In case you are not sure what I'm talking about, this is an input shaft:


Master Cylinder
73 K10 has a 1" bore on the MC (which is brand new!)
83 K30 has a 1 5/16" bore. You need the Hydroboost unit and the Master to match.
Mods: Bought the 83 K30 Master cylinder $45. I bought a new one. I have had the re-manufactured ones leak, and then you have to bleed everything again. Not worth not paying the $20 more for a NEW one.

Somehow when I started this project my radiator started leaking and I lost like 2 gallons. I guess it was good timing, so I put in a new
radiator, hoses, belts, and trans cooler lines. If my back was not so achey I would be stoked!

Here are some ugly pics of my ugly project:

The gooey, messy donor:


Please Memorize how this goes together:


Power steering fluid mess


Are these brackets the same?


And... again. Same... or different?


Clue: NO!!!!

Here is the pump installed with the stock bracket, note how close the return lines are to the frame:


Pulleys line up when all bolted down:


Putting the Power steering box on, one of the threads was buggered. Found out *after* I had it 3/4 mounted.
Took it back off, and one of the threads was not happy. No SAE tap set.
Neighbor-gear-head-buddy was not home so...
Make-your-own-sorta-tap

[LT7A]

Nice work summarizing the information. Nice to see the truck it's going into. Good looking rig.

[swissarmychainsaw]

I got everything back together for a test (about 12am!) fired it up and realized my trans hose clamp was not very tight! That was a friggen mess!

I left the stock master cylinder on there just to test it out, and I have Brakes!
BAM!

Now I'm thinking, what if I just leave the master cylinder on there? Would the smaller bore cause any serious problem?

[swissarmychainsaw]

Saginaw gearbox was leaking like crazy from the input shaft seal (1984 K20).
Input shaft seal rebuild kit was about $7 from auto parts place #8525

Here is how to do this while on the vehicle.
Well, really I'm an expert at doing it wrong, then figuring it out, then doing it right! So here's just the "right way".

Big Mess:


Remove the bolts NOTE THEY ARE DIFFERENT SIZES!!!!!


Wiggle the shaft off:




The leaking oil should make the lock ring easy to get off. Here I'm using an impact socket.
I tap on one, then move to the next, then next, until it starts to move. I've seen lots of damaged lock rings from people wailing on them.





REMOVE THE SNAP RING! (not pictured)
Often it's so nasty in there you might miss it! (I did, and I have done this before!)

Yeah did I mention the special tool? There are ways around this, but if you own a GM truck(s) eventually you want this.




The O-ring was brittle and horrid, I turned it upside down and tapped it gently out with a screwdriver and hammer.

Here I am installing the new seal gently using socket, evenly tapping around the circle so it goes in straight. Drive it down past the snap-ring recess leaving room for the dust seal and snap ring



Then use a pick and remove the large o-ring, install the new one and the dust seal from the kit and you are good. It was late, I was tired and did not get all the pics.

Tip: when you re-install on the input shaft, make sure you turn the input shaft clockwise so that it seats back inside the steering gear.
If you do not, it will stick out too far and make it VERY hard to get the rag joint and shaft together. It will also not engage the gears properly.
You should be able to line the rag joint and shaft up by hand with a only a little force.



Bleed the system by raising both wheels off the ground and turn full left to right 10-20 times. I check/fill the steering fluid then do 10 left to righs, then check the fluid, then 10 more. Done.

[swissarmychainsaw]

After driving it some, here are conclusions.

Pedal feel is very firm and "wooden". Some don't like that. The vacuum brake set up is more ... sensitive feeling. Hydroboost is like stepping on a 2x4, and you stop. Not delicate feeling.

This fixed my braking issues, which I believe are the result of low vacuum produced by my worn out 350. So I'm happy with that.

Cost?
My used set up from craigslist was like $100 but you could get all new stuff from rockauto (excluding the gear box) here are some VERY rough numbers if you got new stuff

1983 Chevy K30 Pickup w/5.7
Hydroboost: 140.00
1 5/16"Master cylinder: 44.00
Hoses: $50.00
Pump: $60.00
Pulley: $30
< $400