anyone done a hydroboost conversion???

[red02chevy]

I know this can be done on newer trucks. (99-07 Chevy truck)

Now has anyone done this to these trucks? I am going to be using a motor/tranny out of a '88 suburban so i need to know if it will work with that motor. My grandpa has a parts suburban that has a diesel motor with the hydrobooster on it so i need to know if i can pull everything off it and use it on my truck? I know I will probably need the powersteering pump, all the lines, pedal, actual hydrobooster, master cylinder, and it looked like I will also need the steering gear box.

Thanks for any help.

[BLE 'BURBAN]

All you should need are the hoses, MAYBE the pump, definitly the hydroboost unit with master cylinder. The pedals and the steering gear box are not necessary to swap out.

[Slonaker]

I'm pretty sure that Ivan D. here on the board has done the conversion...

Slonaker

[Russell]

You'll need the booster, master cylinder, lines and pump. If you have an 80 or older steering box on your truck you'll need to get a custom line made up that runs between the booster and the steering box high pressure side so you have a flare fitting for the steering box, and an o-ring fitting for the booster side. The booster return line runs to one of the power steering pump's return lines, and the final line runs to the pressure side of the pump.

On the steering box you'll have the high pressure side supplied from the booster as mentioned above, and a return line back to the power steering pump as well. The hydroboost power steering pumps output a bit more volume and pressure than the regular ones do, and have the second nipple for the booster return.

You'll also need to switch the lines around on the booster (take the rear one to the front, and the front one to the rear), but they do thread right in no problem.

Putting the pump on is fairly easy, just rent / borrow a pulley puller to remove the PS pump pulley, undo the four bolts that hold the bracket to the pump and swap it out with the new hydroboost pump. The hydroboost pump has a significantly bigger canister than the old one, but it should be just fine with a V-belt bracket. I had some clearance issues with my serpentine bracketry.

I had a phenomenal upgrade in braking power doing this swap, it was well worth the effort!

[Ivan D.]

Yep, I got it in my '79, tis real easy - all you need the hydroboost unit with the connecting rod for the pedal, the high pressure lines (both the one from the pump and the one to the steering box), and possibly a new master cylinder. Tis pretty much a bolt-in deal, however here are some things worth mentioning:

1. Mounting the hydroboost - normally those bolt up to the firewall via 6 studs, which should be the same setup as what the vacuum boosters use, however if installing hydroboost on a truck with manual brakes the top two holes in the firewall will be blind with no studs - you can drill them and install studs, or you can just leave them as is and bolt the hydroboost using 4 studs only, new trucks and vans use only the lower 4 studs anyways and their mounting brackets don't even have provisions for the top two studs in question.

2. Pressure hoses - the set I got was from some '80s truck and those have rubber O-rings to seal the hoses to the pump and steering box, however my '79 pump and box would only accept flared lines - solution was cutting off the lower ends of both '80s hoses and both ends of my stock pressure line, then sliding the stock flared nuts on the now bare '80s lines, then flaring the "new" lines so they seal to my stock pump and steering box - nothing too involving really, just make sure you have a good flare tool that can handle 3/8" lines. Double flare is recommended tho not necessary, I do just fine with the single-flared couplings.

3. Master cylinder - apparently the master cylinders for the vacuum assist brakes ain't quite the same as those used with the hydroboost, major difference being it the depth of the slot in the master cylinder's pisron where the rod from the power assist unit slides in - IIRC the hydroboost needs a shallower slot, so if you reuse the master cylinder from the vacuum brakes there will be some decent free travel before the brake pedal engages the master cylinder piston. You could snag the original hydroboost master cylinder, but I'd recommend getting a new one - they are cheap and having all new seals is good from a safety standpoint.

4. Brake lines - hydroboost cranks out some massive line pressure, so make sure your brake lines are up to the task - when I was test-flooring my truck in my carport I blew both the left front line near the prop valve and the rear line behind one of the frame crossmembers, so I went ahead and replaced them all, bypassing the prop valve - I now have all-new brake system with a manual bias-adjust valve, this way truck stops on a dime when empty and I can still increase the braking power to the rear wheels for whenever I haul/tow something heavy. Good brake bias valve can be had for as cheap as $35, places like Summit and Jegs have them in stock and it usually comes with fittings for 3/16 brake lines included.

Pics of my setup can be found here: http://www.supermotors.net/vehicles/...ry/15769/58405

Also some moderator please sticky this thread as important tech article or FAQ or something, there seems to be quite the interest developing in hydroboost conversion lately

[D13]

Fins a j-yard diesel and rob it. Comes with hydroboost (like on my 87). M/C itself is generally the same, PS pump is the same or a bigger output, lines as noted above are different for the early boxes.

[red02chevy]

thanks for all the help guys. I did this conversion on my old truck. it was a 2002 single cab short bed.

I will try and do a write up on this when I do infact do the conversion. I need to go pull all the parts so someone else doesn't find out they need everything more then me.

if anyone else knows anything about this. post up. the more help the better

[K30_dump]

Hello everyone,

I have never driven a truck with hydroboost, so I'm curious how it performs. I am currently building my K30 dump (454, TH400, NP205, Dana 60 and 14 bolt w/3.73's; dually of course) and was GOING to use a vacuum booster, but decided to go with the hydroboost (being I have two complete boosters laying around). Since the truck is not together yet, I was hoping some of you could share how well it works. More assist? Less assist? Any help is appreciated.

Thanks,

Joe S.

[Ivan D.]

Ever driven a truck with manual brakes? Well imagine same feel at the pedal, only with TONS more stopping power. Yes, it has more assist than vacuum boosters, and is also more responsive, and in general feels "tighter".

[K30_dump]

Hello,

Sounds awesome. Thats exactly what I want, hard pedal but touchy braking that'll put you through the windshield. Thanks for the insight.

Joe S.

[Ivan D.]

It ain't as touchy as you may think, tis just not as mushy as vacuum assist systems kinda-sorta are.

[K30_dump]

Hello again,

I think I got you. I look forward to driving it so I can find out

Thanks again,

Joe S.

[boatpuller]

hydroboost is everyhing ivan says it it is.my 79 was a diesel and i kept the hydroboost just because i love the feel of the brakes.it is starting to get a look by alot of car customizers.if you read any of the hotrod type magazines you'll see after market hydro systems for sale from different part places.they don't use vacum so therefore you can run some wild cams.

[streetstar]

i have a hydroboost system -- it has 3 lines going into (or out of) it

Prob: the steering box on my '75 only has two lines

Is the 3rd line for a brake booster or something? I thought it was just steering and was trying to locate a standard p/s pump to replace it with, but now you guys have me thinking otherwise

[tyjoja]

nice write up and pics Ivan. I thought the hydroboost had an even bigger vaccuum booster. Your set up looks nice and tidy. I'm going to switch my manual brakes to power asst. soon but now might have to rethink. saw a booster with master cyl. on craigslist for 40 buck and was thinking about getting it, but I don't know now. thanks bob

[tyjoja]

russell, I was reading your thread a little closer,and maybe I didn't quite understand, hydro boost requires a different power steering pump? I'll read up on it again. thanks bob

[Russell]

Streetstar:

The booster has three lines as you noticed -- One is a high pressure supply from the pump (the big threaded fitting), another is a high pressure supply to the steering box (small threaded fitting) and a return line (hose clamped over a nipple on both sides).

The steering box has the normal two lines, pressure is supplied by the booster, and a return line to the pump (hose clamped over a nipple on the pump side, threaded fitting on the steering box side)

tyjoja:

Well, it doesn't require it, you can use a stock pump, but you must find a way to hook the booster's return line back into the pump's canister like the steering box does. The hydroboost pumps do hold more fluid, and have higher pressures / flow rates than a regular power steering pump does though.

[Ivan D.]

you can actually T-ee the two return lines together and then run a single line to the pump, however it is necessary that you hook up the lines so that the one off the brakes has a straight shot through the T-ee. I actually used a Y-fitting for that, the fluid dumped from the brakes goes straight through, and the flow off the steering box merges into that from the side.

[tyjoja]

thanks guys, sounds interesting

[454HO]

Bringing this old thread back because I'm wanting to hydroboost my '86 and have a couple questions.

The BB I got came with a hydroboost PS pump, so that part is taken care of. I bought a re-man'd booster from the auto parts store for an '86 diesel truck thinking it should just bolt on, but I ran ito a couple issues. The booster I bought is a Cardone 52-7248 (application - P/U JD3, JD5 w/HYDRA BOOST).


First, the cab has 6 studs sticking into the engine compartment for the vacuum booster to bolt to. The hydroboost booster also has studs in the 2 middle hole positions. I have no problem knocking the studs out, and it should align with the studs on the cab, but I thought this should be a bolt on deal.

Second, the pushrod that connects to the brake pedal is about 1" shorter than the one on the vacuum booster, plus the hole is a bit larger. Isn't this going to cause a problem? Seems like the brake pedal will be too low to the floor and I may need a bushing or something to take up the slack.

This sounded so easy from the previous posts in this thread. Did I get the wrong booster or am I just doing something stupid???

[Russell]

The pedals I have in my 80 were from an 85+ diesel pickup, so I suppose it was just dumb luck that I didn't run into the brake pedal problem. I had no idea there was a difference there...

The booster did bolt straight up to my firewall though, all 6 studs lined up no problem.

[zombiescustoms]

I did a GM hydroboost on my 74 bronco with 4 wheel drums and all I can say is holy balls batman!! the thing stops like crazy even with 37" tires, Most definatly a good upgrade!!

[454HO]

Well after some more searching I found this thread by Yukon Jack. Looks like he ran into similar issues with the mounting studs and the pushrod.

This one fits very well, all I really had to change was knock two of the studs out of it, drill two new holes, use bolts in place of the two studs I took out and modify the push rod. Have to see if anyone chimes in with info on something that actually bolts in place with no mods.

So like I said, knocking out the studs on the booster is not a problem. But I guess I will need to modify the pushrod somehow to mate it to my brake pedal.