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Since my vacuum booster has a bad end seal, instead of replacing it with another vacuum booster, I was thinking of running the hydraulic (or 'hydrobooster') that came on the v8 SN95 Mustangs.  I have all of the components, however ran into a minor bump in the road, and was wondering if you guys had any ideas.


There's three lines going into the booster assembly. 


1. High pressure line from the pump.

2. Low pressure return to the reservoir.

3. High pressure to the steering rack.




Since I do NOT have power steering, what should I do with line #3?? I don't think I can block it off, as it would put a ton of strain on the pump (like when you go full lock on a p/s car, it makes the pump whine).  But on the other hand, I'm not sure if I can just tee it to the return line and have it go right back into the tank.


I want to get going on this install ASAP, as I start working again next week, so any help / ideas would be greatly appreciated! 



Edited by yellowoctupus
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OK, It's all installed, just waiting on a new high pressure line to come in and my new (longer) belt.  (Grr...I wanted to do the whole project in under two days.  Oh well.  If the high pressure line I got with my booster hadn't had the end broken off before I got it it would be all finished.


I took an old booster and cut off the threaded 'input' push rod and yoke, and cut off the Mustang push rod and welded them up together:




Since there's three lines at the booster (high P in from pump, low P return to reservoir, high P to steering rack) I just took the high P to steering rack and returned it to the reservoir.  Hopefully it'll work ok without backfeeding into the low pressure outlet or anything funny.  The original return line is setup to take the return from the booster and the rack, so I cut off the original rack line, and gave it a bubble flare to keep the line from slipping off.  (The bubble flare thing actually worked better than I expected.  It's really on there.)



The attached PDF is a template for the new hole pattern that needs to be drilled in the mounting flange.  It's graph paper, 1/4" per square.  The Datsun pattern is 100mm wide, 70mm tall on M8 bolts and the center hole is offset 9mm low.  (see template)  I just pounded the old studs out, then drilled 21/64"  holes and pounded them into the new holes.  They're not as tight as the factory bolts, but they're not going to fall out and certainly not going to spin so they're good enough for government work.




Edited by yellowoctupus
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I emailed hydratech in regards to something on their FAQ page:


Q: Can I install this kit if my car does not have power steering?
A: You must have power steering installed and operational in your vehicle in order for this system to operate.


I expected a quick answer from them, but I got a big ol reply back the next day.  Very on top of things, that's for sure and pretty helpful!




That is an interesting build you are running – can’t say I’ve heard of one before! Yes – you are correct in your notion that these types of systems can run stand alone (without actual power steering). I wish it was as simple as plugging the high pressure output port that goes out to the steering gear, but this would have the same basic overall effect as plugging the high pressure output port on the PS pump (which would deadhead the pump and fry it in less than a minute’s time). Since the PS pump output cannot be deadheaded and these brake units are designed to be flow through devices, the high pressure output must be allowed to flow back to the power steering pump. In a standard scenario with a steering gear involved, the high pressure output would flow through the steering gear and then return back to the reservoir. FYI - When eliminating the steering gear from the loop, there is no way for the plumbing downstream of the brake unit to pressurize, as there will never be a load placed against it. Spoken the other way around, the only line that could ever pressurize up in a scenario where the steering gear box has been eliminated is the HP line between the PS pump and the brake assist unit’s HP inlet port – it will pressure rise in response to how hard you apply the brakes as a function of basic hydraulic actions, but no other line will build pressures (just flow).

                Ok, if I haven’t lost you yet, the line that would normally connect to the steering gear HP inlet port will now instead be redirected to connect to the PS reservoir’s low pressure return. If running a full size Saginaw P for instance, you would take the fluid flow out of the HP port on the brake unit that you were thinking about plugging off (that would normally connect to the steering gear HP inlet port) and simply connect it to the low pressure return nipple on the PS pump housing. This would make you think that you should still be able to T the LP return line from the brake unit’s brass nipple together with the other line, but we have found it gets crabby. The workaround here is to install a second low pressure return line nipple into the PS pump housing to accommodate the LP return hose from the brake assist unit…


If you are doing such on a mini pump running a remote reservoir, this item makes this a breeze to plumb:


Reservoir without hose kit:




Fancy polished version:




With hose kit:



(AN-10 pump feed nipple / AN-6 return nipples)


* Run the high pressure braided line that would normally go to the steering gear to the silver AN6 nipple in the middle on the bottom of the tank, run the low pressure return line from the brake unit to the gold colored AN6 nipple on the bottom right side of the tank = presto! All set  J


Attached to this e-mail is a drawing / picture that might help picture on a Fed / Sag P + here is a link illustrating a mini pump arrangement (imagine eliminating the rack in this drawing):




The installation of one of our systems into a standalone scenario (without actually running power steering) requires that an additional dedicated AN-6 nipple be installed into the PS pump reservoir. The second high pressure line (that would normally plumb to the steering box or rack) will now be returned back to the PS pump reservoir unused instead of connecting to a steering gear. It is suggested that this additional hose nipple be installed approximately 1/3 the way up the reservoir - 1/2 way up the reservoir is considered the max suggested height. In your case, since you already have a factory "hydroboost spec" pump with twin return line nipples, you could obtain a AN-6 steel nipple and braze it onto one of your existing push on type hose nipples. The reason that this needs to be a secure AN type line connection to the reservoir is because of potential pressure / flow variances that will occur when the braking is actuated and released - push on / clamped connections for this line CAN work, though is not recommended per possible hose blow off while in use. Unlike OEM assist units, our assist units are specially prepared (proprietary mods) to run well either with or without power steering without worry of unregulated pump flow characteristics. If you are performing a DIY installation using an OEM based assist unit, your results may vary...

You would plumb the system as follows:

* High pressure line from the PS pump to the assist unit inlet port as usual

* High pressure line from the assist unit high pressure outlet port to the dedicated AN-6 nipple installed into the PS reservoir

* Low pressure return line from the assist unit to the PS reservoir as usual (may use a simple push on hose and clamp connection)



If you should decide to run power steering at a later date, you would then re-route the high pressure line from the brake assist unit down to the steering gear, then run the low pressure return line from the steering gear back to the AN-6 hose nipple already installed prior = quick, fast and easy change if desired down the road.

Also, you cannot simply plug the second high pressure port, as this will dead head the PS pump and burn it up almost immediately. These systems are designed to be plumbed in series, and they therefore must be plumbed as flow through devices...


Let me know what further questions may come to mind – feel free to call to discuss.


Jim Petty

Retail Sales Manager


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My only experience with hydroboost was with a local autocrosser that installed a hydroboost setup on his 600+ hp C4 vette.  The first event pretty much every corner he came up to he would lock up the brakes, he complained about how difficult it was to modulate the brakes.  It took him a long time to finally get used to the new brakes to where he was competitive again.  Not trying to discourage you just saying it might take some re-learning to get back up to speed again :)


Overall, this is a pretty neat project, I'll be very curious to see how it turns out.  I've personally have never quite been happy with how little assist our brakes seem to give, at least compared to power brakes on newer cars.

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Since I haven't had power brakes in this car for almost 5 yrs, I'm going to have to be super careful once this is all installed.  Even driving my buddy's 240z with vacuum power brakes I slammed myself into the seatbelts just going down his driveway!   I'm a little surprised I couldn't find anybody else on Hybridz that had done this yet; plenty of guys over at the factory five forums have however, which is where I got some of those diagrams posted earlier.

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I pronounce this project a SUCCESS!  I finished up the hoses, got a new belt (Napa 060604 13/16" 6 rib serpentine belt, 60 7/8" circumference) and topped it off with some ATF and after I pumped the brakes a dozen times while refilling the reservoir, (to fill all the lines, and the booster itself) a test drive almost put me through the windshield.  Ha, no not quite, but they're probably the best brakes I've driven a car with.  Super bite with very little driver pressure. 


I think the project total came to just under a $100, as the booster/master cylinder with three hydraulic lines came up to $65, and the new belt ran me almost $30, and it took almost a quart of ATF.  That's cheaper than a rebuilt master cylinder!!! And, it had WAY more power. 




Since it was going to take about a week for the stock 96 Mustang hi pressure line to come in, I just made a braided one out of some random 3/8 line I had in the garage and some -6 JIC fittings.  I'm pretty sure the stock Mustang line would have also worked, had the jerk who removed it not broken the end off.  Admittedly though, it is really hard to get that high pressure line off the bottom of the pump.  I heated up and bent a wrench to turn the fitting.  Wish I had done that before going junkyarding.  I think it took me 20mins to take off one fitting there. If you braize up your own fittings like I did, put the other end into a tin can full of water, it keeps it nice and cool, so it won't cook the o-ring that's in the Ford swivel. 




Ford power steering hoses have a peculiar sealing method which uses a 1 time use teflon washer to seal the fitting to the port.  Since NO-ONE in town had them in stock, the guy at Napa found some really thin copper crush washers which actually worked perfectly.  And they're $ 0.75 apiece, not $4.  I was skeptical, but they're so tight on the fittings that they're difficult to 'thread' on.  Napa P/N 1246.  Not a drop out of any of the connections (qty 4 in my assembly).




Edited by yellowoctupus
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  • 4 weeks later...
  • 3 months later...
  • 5 months later...

Ive been diligently working on this on the side for the SBC guys. I am nearing install!


So far I have figured out most of my problems.

I ended up keeping the V belt style setup. A serp belt would be nice, but with a basic setup like mine it would require that I go fancy and buy ALL new accessory brackets to clear the belt and either use custom idler and tensioners, or buy a really expensive kit to make it all work. I like the really basic look I have going on in my engine bay. I want it to appear old school and simple so V belt it is.


This is the ALT bracket kit I used:



Its really simple... but one of the allens is hard to tighten properly and the adjuster joints are a little big for my particular alternator


The Saginaw PS unit is pretty universal. GM and a few others all used the same unit... ON EVERYTHING! The reservoir housing was the biggest change through all the units out there!  The only other change that I noted was the pulley attachment. I prefer the press on type, but there is also a cone style one with a woodruff key. GM made V belt pulleys for both style pumps though. The Corvette in particular used the V belt and a press on style.


The Vortec/ TBI sbc units would not work with the V belt setup! The reason is the belt alignment and the back low pressure line do not physically work out with any standard brackets offered. But that is only the reservoir that is the issue. Housing options are abundant!



03-05 GM unit with remote reservoir.


This style works as well... see the low pressure line is near the edge... It just cannot be near the center of the pump with a V belt!


Here is an example of one that WILL NOT WORK with a V belt:




This is the PS brackets I went with.





The TBI mounting bracket was for the serp belt and it sits out from the block which will not allow me to run a V belt on the correct axis. This explains why the low pressure line hits the block with the above pictured mount kit.


This is the pump I went with. I have a brand new re-manufactured pump I will install in this new housing.



For the Hydrobooster setup I would recommend seeking out a pump that has 2 low pressure return ports! The remote reservoir type works perfectly for this as well. Most of those reservoirs have a low pressure bung and the pump has one as well. This is why I went with the pump housing with 2 low pressure ports. There are 2 low pressure returns from the booster that need plumbed as outlined in this thread.





AS you can see the pump knocks out from the reservoir housing. Replace the seals! These are notorious for leaking! They always leak!... Did I mention they leak? LOL Remove item 27 and items 28-33. Thread in 2 longer bolts were the studs were for 27 and work the pump out of the reservoir with a rubber mallet.


Moving on to the fun parts which I have planned out but not executed as of yet. The lines!


So the 2 low pressure lines can be installed to your reservoir or pump with hose clamps after properly trimming them to length.


The High pressure line though is a bit harder, but do not fret! There are places in most major cities that can make lines from scratch. For instance here in Salinas Ca I have CSC... which is also in Gilroy. They are local only though. Or you can find a local John Deer or CAT and have them do this as well! Its really simple. You will need the high pressure line from the GM PS unit though. Its the same size line as the Mustang! The best way I can figure doing this, but not the only way, is to remove the hard line off the end of the GM line that would go to the PS box. This leaves you with the hard line threaded into your PS unit and a bit of rubber line. All you have to do is measure the hard line from the booster to reach that rubber line and then have the 2 hydraulically crimped together and your plumbed! Im gonna walk mine into QUINN CAT and pay them to put it together. They have the collar to do it in stock.

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  • 4 months later...
  • 1 year later...

Want to use aftermarket lines?


Here you go for Hydrobooster side:


Russel part numbers

High Pressure IN 18x1.5 oring to -6AN 64808 with 620421 90 crimp

High Pressure OUT 16x1.5 oring to -6AN 648060 with 620421 90 crimp

This will delete those fitting you had problems with Phill.


Mine is finally coming together.

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  • 1 year later...

First try, it might be enough to just use the L6 power steering pump from a ZX, or Maxima with the stock Nissan pump.  I'm guessing it won't be as high of a pressure, but if the Nissan pump put out (totally hypothetical numbers ahead...) 1500psi instead of 2000psi from the Ford pump, it would still provide great stopping power compared to the vacuum booster.

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I planned on doing it but moved away from an L series for my car. I'll still be using a hydrobooster but I'll probably be using a factory PS pump from the 7M I'm planning on going with.


I bought a sn95 cobra (I think 2004) PS pump which I was going to make a bracket to mount to the L6 where the AC compressor went, run the hydrobooster from the same 04 sn95, and run an 04 sti power steering rack for the quick ratio. Still gonna do all that sans the 04 cobra pump on L6 motor.

Edited by jthom5147
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