Hydroboost swap

[Hammer Head]

Anybody ever drop on a hydroboost in place of the vacuum booster?

[Sparky2263]

Lots of people have gone the other way. Not a hard swap but adds about 30-40 lbs. of weight.

[Hammer Head]

Well, yeah.. It is a little heavier but doesn't hydroboost give a little better feel & stopping force, more room for an engine swap or if you're slammin it down.. more wheel clearance? Also if you're engine cuts out doesn't it still allow you to brake.. where a vacuum setup would only allow one maybe two presses, if that?

[Sparky2263]

I'd just go manual brakes if I had those concerns. Yeah, you gotta push a little harder, but it ain't that big a' deal.

[Hammer Head]

The main reason I'd be doing this swap is I'd have C5 rotors & calipers at all four corners & I currently have C4 Z51 package wheels, which would be a lot of rotating mass, so I don't believe manual is the way for me. My secondary reason is the 6.0L swap, w/ Z06 cam.. maybe a little more room & don't have to worry about vacuum. If I didn't have the big tires & the big brakes going on it I would problably go w/ manual, but I'd like every little bit helping me throw the anchor.

[Sparky2263]

Sounds like a good decision to go hydro-boost.

[Hammer Head]

My question about the assist unit is this.. would the mounting flange from an astro's unit line up w/ the flange holes on the s10, or will it need to be modified? I've read about how to plumb it, but if you know any better ways I'd love to hear it.

[Sparky2263]

It's basically a bolt-in as the 4 studs are in the same location.

[Hammer Head]

Ok, I thought so but wanted to ask. Whenever I finally get some time & a little cash I'll get this swap goin & snap off a few pix in case anyone else is curious as to how it's done.

[Hammer Head]

I remember a while back having to make my own fitting from a -6 AN block-off & an 1/8" NPT to 1/16" NPT inverted flare w/ rubber O-ring adapter (mostly used in the old mechanical gauge kits- some don't have the O-ring. But you can always get an O-ring from the hardware store). I drilled & tapped the -6 block-off to accept the 1/8" NPT. The 1/16" NPT threads into the booster.. I could have gone & bought the part (it's a rare piece & I only found one online) for about $25 plus shipping but I already had the two fittings on hand. Oh, & not to be worried about the fitting adaptation blowing.. it's on the return side & the pressure's a lot lower. Remember if you're making or buying lines get ones rated to 2500-3000 psi on the pressure lines (this would be the braided teflon lines). It's ok to use plain old braided line on the low pressure return line (braided line is rated to 200-300 psi). Pix to come, possibly w/in the next comming weeks.

[Hammer Head]

Well, I took a ride & got a few things done today. As for the hydro-boost swap.. all I did today was prep everything so I could just pop out the vacuum booster, just bolt everything up & load it w/ fluid. I made my AN lines, sited a route for the lines & cleared insulation away from the four studs/ nuts in the cab. I'll take some pix when I get everything swapped... who want's to see a few hoses?

[87wildside]

I do

[Hammer Head]

ok, hopefully next wk I can get back out there & finish this up. Then you can see my lines... along w/ the rest of the swap. haha

[Hammer Head]

Well... good news & bad news. Here's the good.. I got the unit in & all plumbed up. Bad news.. unit was faulty, had to pull it back out, ended up staying the night over at my gma's house & then had to get carted around the town ordering up the booster & then got dropped off at my g-friend's house.... 3-5 day wait on the booster. Ordered up one from an '02 2500 silverado. Anyone want the vacuum booster as a core? The pushrod from the pedal to the unit was cut, just pay shipping.. if not I'll just pitch it.

[Hammer Head]

& a picture of the lines just for Eric.. hahaha.. sorry I didn't snap one of the finished install but I had to pull it all apart so I could drop off the core.

[87wildside]

soooo purdy....That sucks about the booster.

[Hammer Head]

Oh well.. I guess through some readin a lot of guys are using the '94-'95 astro HB. They say you need to cut the pedal rod down. I'm not too into that but if I gotta, I gotta. Maybe the unit I'm gettin will work out. Just hope it's the same 'flat' mount to the firewall. It should be.

[Hammer Head]

Once I figure all this out I know I can find all the stuff cheaper than some of the sites sellin kits. So far, even though I need the new booster, I'm breakin about even on just a kit for the lineset from some places.

[Mikz86TA]

So, tell me about this HBooster and the benefits? Is this going in you X?

[Hammer Head]

Frees up space (I can see the drivers plugs now), it's about 1/3 the size of the vacuum booster. It weighs about the same..at least about the same as a 2nd gens booster. It increases braking power/hold by 500-1000 psi. which is great for bigger brakes & wheels. It also leaves ya' w/ about 4 pumps when you loose power, unlike the vacuum booster where you have maybe two good pumps. Yes, goin in the X.

[Mikz86TA]

I want to see installed pics. Sounds like a good deal though

[Hammer Head]

You know the basics about it, right? How it's run off the pwr steering pump & all that fun stuff?

[87wildside]

So, tell me about this HBooster and the benefits? Is this going in you X?You get to add braided line under your hood!

[Hammer Head]

LMAO.. yea, that too! But you could always use OEM hoses if you wanted to cheap out. I'm gonna look into how much I can make a kit for if anyone else wants to do this. I know it'll be a few $$$.

[Mikz86TA]

BS...if I were gonna do it, I would go all out. I didnt know about it running off the ps pump though.

[Hammer Head]

Yea, if at least a couple guys are interested I can put together a few complete kits. That's the booster, lineset (w/ fittings installed), all the connectors & instructions. I'd price it at $550.. I've seen companies selling for about $650-700 for an unfinished kit, so I feel this is fair. Lemme know whatcha think.

[Mikz86TA]

Get some pics and finish it up. Then test it out. I personally am not gonna do it to my truck because I got too many other things to focus on right now. But alot of guys would be interested I am sure. Especially clearance being an issue stock and also if bagging it to lay frame I would assume this to be a benefit. At least your figuring it out and doing all the R&D which most people dont have the talent to acheive. If I were you I would market it and sell it. Let us know how it all goes =)

[Hammer Head]

I plan on gettin it all squared away & then come out w/ the kit. I don't want someone else gettin any problems if I can avoid that. Soon as the part comes in I should be finishin this up & gettin some pix up. It's been used by a few different S truck owners when layin frame & also when 22's or some other huge wheel is used.

[Hammer Head]

Ok, figured it all out & got it together... new parts help. hah. Here's some pix. Pump makes some noise because there's still air trapped in the system. The repair manual reads that it'll take about 500 miles to get the air out.

[Hammer Head]

I have the accumulator installed in the "hot-rod" position.. the "low-rider" position would be 180* from the pictures. "hot-rod" gives more room engine side & "low-rider" gives more room tire side.

[Sparky2263]

Very neat, very clean.

Thumbs up.

[87wildside]

Nice work! Damn you, now I want one...haha. You still planning on selling the hose kits?

[Hammer Head]

Sparky: Thank you very much. Seems to be worth the effort.

Wildside: Sure am if there's people that would like them. May take a little while before I can get some units. Need to search the yards for cores because the firewall mounting plates don't come w/ the reman'd units. May take a little less than 2wks for kit to be completed & shipped. But let me run a few wks of r&d on this so I can see if any problems arise.

[Hammer Head]

I also would like to say the truck has incredible stopping pwr.. I put the brakes on hard to see what it would do. All I have to say is good thing I wear my seat belt or else I would have gone through the windshield it stopped so fast. haha. Figure these unit were used in vehicles w/ GVWs of 4500-7000 & our trucks are 2800-3800. So we're at half of what it was designed for.

[Hammer Head]

Hey Mike, another thing hydroboost is good for is the unit doesn't require vacuum to run it. This may be something helpfull for the guys w/ turbo/sc & high cam'd engines that don't really have that vacuum.

[87wildside]

How is the ABS working out with it?

[Hammer Head]

I grabbed an ABS compatible unit so as of right now, no problems.

[Mikz86TA]

Thats what I need on the TransAm. I have a CraneCams vaccum reserve, but I can still tell its weaker tha it should be. Hey Mike, another thing hydroboost is good for is the unit doesn't require vacuum to run it. This may be something helpfull for the guys w/ turbo/sc & high cam'd engines that don't really have that vacuum.

[Hammer Head]

Does your booster/MC angle upwards or does it go straight out?

[Mikz86TA]

So you reused your resivoir and ABS? the hydroboost is a motorized actuator?

[Hammer Head]

Yep, bolted the stock MC/reservoir & ABS up.. no problems. No, it's not a motorized actuator but instead it uses fluid to activate it. I think I've read something somewhere about a motorized unit but that was a long time ago & my memory of it is hazey.

[Mikz86TA]

OIC.....it uses the PS Pump to energize it by the t-fitting on the pressure side I guess and all the ABS and brake lines to the master cyl are intact as stock. I cant remeber if the TA is abgled or straight. I think the mcyl is anglrd and the resivoir is straight. The firewall is straight from what I remeber but that seems odd for some reason. Ill look tomorrow if I get a chance. Im doing some work on it right now anyway.

[Hammer Head]

That T fitting is actually on the return side so the HB plays nice w/ the steering. If I swapped on a p/s pump from a HB truck (assuming it fits the bracket) it would have two returns on the pump itself & wouldn't need the T there.

[Hammer Head]

The reason I ask is because GM made some HB units w/ angled plates.. but I also believe those same units had a longer push rod as well. ..maybe we can get somethin figured out for your TA..hehe

[87wildside]

How much did the booster cost and was there a core charge?

[Mikz86TA]

Heres an existing pic I have online of it. You can sort of see how its made. Ill have to get a better pic one day but Im doing some work on it right now and its a mess under there. It definately looks angled http://i157.photobucket.com/albums/t43/Mikz86TA/Car/TA-motor3L.jpg

[Hammer Head]

Eric: Yes, there's a core charge. I can't give a direct number because it depends on where you get it from. But, I'll say total w/ core is anywhere from $185-245. Some units need more work to drop in than others.

Mike: It looks to me like that booster needs the angled plate. Do you have any idea how long you pedal rod is? If you can get up there could you do me the favor of measuring from the eye of the rod to the boot on the booster & that should give a good idea of what HB unit you'll need.

[Mikz86TA]

Question.....is the angled plate like this // or like this /] ? Hope you can figure WTF I am trying to say with typing. Hehehe And the rod length is the one from the pedal inside to the back of the booster? Or am I way off?

[Hammer Head]

lmao.. angled plate is \\ not ||. You can give me total length from the back of the unit (inside or out.. just let me know which) to the pedal.

[mxm]

:bump::bump:

so, just curious...hows it working for ya? i wouldd love to have one...money's an issue though, so it'll probably be a no go...but i love the concept of it....

[Hammer Head]

Works great, no problems as of now. R&D is over for the 2nd gens. 1st gens are the new project & I'm comming up w/ a special block off plate because the 1st gens were offered w/ manual brakes & that required the pedal rod hole be elongated & come up above the HB unit.. no problem. I also feel I have the correct unit for the 1st gens as well but would need someone to try it for me. The only thing that's noticible w/ a HB unit over a vacuum unit is they are naturally noiser & you can hear what the p/s & booster are doing. This is normal for a HB unit as I have owned & driven them previously.

[mxm]

do they have any affect on brake pads n the like? do they shorten their life? i know you've only had it on for about a month, but im just curious...

[Hammer Head]

I would think that brake life would be lengthened, not significantly, because it's a more positive stop & doesn't fart around clampin the rotor since there's more pressure behind it. I can't confirm this because I have no tangible proof. I will say this though, my truck felt like it needed at least new pads before the conversion but now it feels better than when I got the truck (had newer brakes then). I have seen rotors that have come off HB trucks before & some have heat cracks.. but those are vehicles that weigh at least twice the amount we weigh. Heat cracks usually happen in racing where the rotors get so hot from constantly grinding the brakes.. you also need to think that most racers use metallic pads though. Organic or semi-metallic should prevent this from happening, also using a drilled rotor would help but I don't feel drilled &/or slotted rotors are worth the $$ for street use. In general I feel only drilled rotors are worth anything unless you need a clean pad every time (slotted rotors peal pads like a cheese cutter) like in racing.. ahhh, sorry I got a little carried away here.

[87wildside]

Drilled rotors have more of a tendency to heat crack. Dimpled or slotted work the best, but for a vehicle that doesn't see any track time they are not much, if any, help.

[Hammer Head]

Yea, I'd still use drilled rotors though.. but that's me being stubborn.haha

[Hammer Head]

I've noticed my pedal not being so hard since I've put about 2K miles on it since I swapped booster units. Still stops like you wouldn't believe. I used to think the brakes were too small for the S trucks but now I see they're just fine all they needed was a better booster givin them the squeeze. I can still hear all the wonderful noises the HB unit makes, though, now that almost all/ if-not all the air is out.. it's not as loud as it was the 1st 2-300 miles. Haven't seen a leak, blown a line, or screwed anything else up. Pump seems just fine w/ everything. I guess if I really wanted to throw the pump GM designed for the HB on the truck the 2500 silverado w/ HB pump mounts up same as the one on the 4.3's brackets (at lease '02 to '02 does). I don't feel it really matter though as some other cars w/ HB don't use a 2nd return. Just thought I'd share this w/ ya's.

[87wildside]

Any progress on the first gen filler plate?

[Hammer Head]

I've got the template traced out, from that nice filler you sent me, but I'm waitin on my neighbor to get me a sheet of 1/4" aluminum.. he's been on vacation. After I get it I should be able to start makin a few plates. My question is this.. do 1st gens not have a flat firewall around the booster or was that filler plate just really bent at the bottom bolt hole?

[87wildside]

That truck barely had a firewall left....hehe. I should have told you that, yes they are flat. Are you sure he didn't just move, been gone awhile. j/k

[Hammer Head]

Haha.. no he's still there, he's also doing an addition on a house he just bought down the street.. kinda busy that way. I thought the firewalls were flat but just wanted to be sure. heh

[Mikz86TA]

So how is the HB doing? You still have the same pads and rotors? Hows the wear and pedal feel and stopping power? Im still interested, but funds are flying around to other things at the moment.

[Hammer Head]

I've since changed my pads.. they were just about dead when I did the HB conversion. Pedal isn't as stiff, feels kind of like the vacuum booster setup but maybe that's because the air has bled out & I'm getting used to the feel, I also haven't changed the rear pads yet. Doesn't make the noises it originally made, again because of the air finally being bled from the PS system.

[87wildside]

Works great, no problems as of now. R&D is over for the 2nd gens. 1st gens are the new project & I'm comming up w/ a special block off plate because the 1st gens were offered w/ manual brakes & that required the pedal rod hole be elongated & come up above the HB unit.. no problem. I also feel I have the correct unit for the 1st gens as well but would need someone to try it for me. I almost ready for one so how is the plate coming? I have found another problem for you, the push rod length is different on first gens. I'll help you out with that once I get mine. How hard is it to switch from traditional to the lowered set ups? I think I will have enough room to run mine the traditional way but I'm not sure because my ride height is going to be pretty low.

[Hammer Head]

I have the 1/4" aluminum plate at the house.. haven't cut it up yet. Figured I'd wait until it was needed to be cut.
Is your concern that the wheel will hit the booster? If that's the case I'd say don't worry about it as there's plenty of room, even body dropped trucks clear it.

[87wildside]

I am more worried about the inner fenders I'll have to fab. I want to keep them as simple as possible.

[Hammer Head]

hmm.. I'm a little worried about binding if you're planning on moving the booster & m/c upwards... I think, so don't hold me to it here, the booster should clear the top of the wheel wells if you decided to come back to the firewall from the top of the stock location. Did that make sense? Also, shoot me the measure ment from the back of the vacuum booster to the outside of the 'eye' (full rod length.. haha).

[87wildside]

I have to move the inner fenders up for tire clearence. I'm not sure how much yet. The MC is staying in the stock location so thats not a problem. I'll add that to my list of crap to measure this week.

[Hammer Head]

Yea, you shouldn't need to move the unit. Just rotate it 180*.. to the non-traditional way (just like you said). Here's a link (http://www.s10planet.com/forum/showpost.php?p=76575&postcount=29) back to the pix earlier in the thread. I didn't fully understand what was said, sorry.

[Hammer Head]

..& I'm sure you know that rotating the unit has no effect on operation.. so, don't worry about that if that's possibly a concern.

[Blazer69]

i'm just gonna buy a hd so i can get hydraboost stock...lol

[ThomasRA]

I'm trying to figure out exactly, what is the best unit to use for conversion on a 2nd gen Blazer? My vacuum booster went out again ( just replaced it 2 years ago ), so I figure the additional expense would be justifiable.

I seem to remember 92-93 Astros mentioned as well as 94-95. One of the local salvage yards here said that they only have 99 and newer and those were completely different.

[Hammer Head]

94/95 use a different bracket that won't work w/ the S trucks. I used a bracket from my 92 astro I junked & a HB unit from an '02 silverado.

[ThomasRA]

Which bracket, the one that mounts the unit to the firewall? Would I still be able to use my existing master cylinder?

[Hammer Head]

yes & yes.

[ThomasRA]

Cool, Thanks.

[Hammer Head]

So, anyone have a measurement on the 1st gen rod length? (back of booster to the outside of the eye).

[ThomasRA]

Where's the best place to get the mounting plate?

[Hammer Head]

Since GM stopped producing & selling them.. the junkyard. Good luck!

[87wildside]

So, anyone have a measurement on the 1st gen rod length? (back of booster to the outside of the eye).I'll try to remember the next time I go. It's almost time for me to buy a kit. :D

[Hammer Head]

I think the 1st gens are 7.00".

[Streetrat]

Sounds like a nice truck, when you get done with it.

[Hammer Head]

Whos truck? If you're refering to mine it's a daily driver.

['94 Big Blaze]

sooooooo.....1st gens unit ready yet....cmon cmon!!:p

[87wildside]

Well he has a first gen so maybe.

I want one but crap keeps coming up and I can't afford it :mad:

['94 Big Blaze]

i hear ya...ya know im wanting to do the 4 wheel disk brake swap from the Z06 vette...and this HB will help alot...

i just need to find a ext cab donar frame...:p

[Hammer Head]

Soon as I get some money to research the 1st gens I'll test it out in my blazer.. but that'd be after the engine swap & a handful of other things. I'm looking at mid-summer to try it out. I just need to find another unit... cheap. Local yard has them for $30/ea. I'd only use it for the bracket & the core charge & get a reman'd unit.