Hydro-Boost Brake Booster for 1990-1993 Chevy Astro GMC Safari Van:
Use the drop down menus to make selections on the unit finish, master cylinder, and hydraulic hose set to put together your kit. Below is a guide for making your selections, along with pictures of the items listed in the drop down menus.
Most 5 lug and larger vehicles produce more than a 1,000 pounds of pressure in the power steering system, the Hydro-Boost taps into this rather than the 15 pounds of vacuum that you hope to get from your engine manifold. Big camshafts and other engine modifications rob vacuum, and diesels don't make vacuum at all. The Hydro-Boost is more powerful overall, and does not depend on manifold vacuum, so it is great for vehicles that have a high performance engine, diesel engine, tall tires, tow a trailer, or are just heavy. The Hydro-Boost should provide an impressive increase in power with your stock pump, but power steering pumps can be modified as well to produce more pressure, which gives you room to get even more braking and steering assist, when using the Hydro-Boost, if you are left wanting more.
The feedback from customers is that vacuum pumps are loud, don't keep up in traffic, burn out too quickly, stock replacements are hard to find after 10-20 years, and aftermarket ones are of low build quality. Going down in size on the master cylinder bore can cheat to spike up the pressure to the caliper pistons, but it reduces the volume of fluid the caliper piston bores get, giving you an incredibly long pedal throw. You can spend a lot of money on calipers that are advertised as "big", but if they are bigger than your stock brakes, they will be more demanding for pressure and volume, so they won't make an improvement unless you have a more powerful brake booster and master cylinder combination to increase the line pressure and volume that they will receive. The power steering pump is belt driven, rather than electric motor driven like a vacuum pump, so it is more reliable, and the Hydro-Boost piggybacks off of this by being added into the high pressure line on its way from the pump to the steering unit. There is usually more potential in the stock front and rear brakes that you already have on the vehicle, so the Hydro-Boost is the logical way to go for consistent braking power if you wanted to put bigger front and rear brakes on, or to make your stock brakes produce. Either way, you want the Hydro-Boost, and it is the first place to start.
The Hydro-Boost is smaller in diameter than vacuum boosters, being about the dimensions of an iron master cylinder, it mates to the firewall/brake pedal and the master cylinder the same way a vacuum booster does, and it fits anywhere a vacuum booster will, as well as many place a vacuum booster won't. The aluminum canister on the side is the accumulator, which stores pressure in case your engine dies to provide you with some braking and steering assist to help you come to a safe stop.
Condition: The Hydro-Boost is very simple in design, and requires little service, typically a fresh set of seals every 100-200 thousand miles. Select "New" if you are replacing your existing Hydro-Boost with a new one, or converting to a Hydro-Boost from something else. If you have an existing Hydro-Boost that you would like serviced, that came stock on your vehicle, or that you bought from us years ago, call or email for pricing and instructions.
The Hydro-Boost comes standard with a durable black paint that will look good and last. We offer powder coat options, which will smooth out the bumps of the casting and look great. Units have to be disassembled for powder coat, and there is a lot of work that goes into preparing units for chrome, so there will be a longer lead time on chrome, powder coat, or other custom work.
The Hydro-Boost taps into the 1,000 pounds or more of pressure in the power steering system, so you will need high pressure hoses and fittings from the pump to the booster, and from the booster to the steering unit. You can choose from the 2 Stainless Braid 2 Rubber Hose Set, 4 Rubber Hose Set, or the 4 Stainless Braid Hose Set.
The first two options use a low pressure rubber hose and hose clamps on the low pressure side, which is all you need, but do the high pressure side differently. The 2 Stainless Braid 2 Rubber Hose Kit will have have a PTFE (generic term for Teflon) inner hose wrapped in a stainless braid weave on the high pressure side, while the 4 Rubber option has a stainless braid weave in the middle, rubber inside and out and is wrapped in a black cloth weave. Both the high pressure rubber and stainless braid type hoses will handle the pressure in the high pressure side of the power steering system. There are many vehicles we cover, and lots of modifications customers do, so the hoses will be extra long, you will run them how you like, cut them, and then assemble the ends on. Some people have trouble with the three piece hose ends for the stainless braid PTFE type hose, the hose ends for the rubber type are a lot simpler, and you may want to select that option for ease of installation. PTFE is better on friction and heat, rubber is better on pulsations but goes bad after 30 or more years. The 4 Rubber Hose Kit will look more stock, and the 2 Stainless Braid 2 Rubber Hose Kit will have more of a performance aftermarket look.
The 4 stainless braid hose kit will use stainless braid hose and high pressure fittings all around. It will be overkill, by a lot, for the low pressure side of the power steering system, but if overkill is what you are going for in looks and performance, you would select that option. Using all stainless braid hoses and high pressure fittings will make everything look uniform and orderly.
All three options will work, so ultimately the choice will be based on the look you are going for in the engine bay. We can pre-crimp the lines if you don't want to have to make them up, you will just need to note the lengths of each hose in the comments section at checkout.
Information About Your Power Steering Pump and Steering Box For Hose Kit:
If you have swapped your pump or steering unit to something other than stock, you will want to note that in the comments section at checkout. Common examples are changing a Ford pump to a Saginaw pump, swapping an LS engine into an older GM vehicle, adding a front runner kit onto an older motor that changes the accessories on the engine, or changing a GM steering gear to a Ford rack and pinion. These kind of modifications will often change the fittings that you will need in the hose kit, so information about changes from stock will help in making sure you get the right fittings for installation.
When replacing a stock Hydro-Boost, the pump will have two returns, so that the steering unit and Hydro-Boost low pressure fitting return to their own fitting on the pump reservoir. When converting from manual or a vacuum booster, the pump will usually have a single return, so the two lines will get tee'd together. A hose diagram and step by step instructions will be included in the box.
A brake booster, also called a power assist, helps you with pushing on the master cylinder piston. A larger bore master cylinder pushes the volume of fluid you want for disc brakes, but it is hard to push with just your leg pressure and the leverage of the brake pedal arm, or with the little assist you get form a small diameter vacuum booster. The Hydro-Boost is more powerful than vacuum boosters, so it will give you more assist in pushing the master cylinder piston, that allows you to use a larger piston bore size to get both more pressure and more volume.
What is important about a master cylinder is bore diameter, stroke length, reservoir volume, which side the ports need to come out, hood clearance, and inner fender clearance. Master cylinders can come in cast iron, cast aluminum with a plastic reservoir, die cast aluminum, chrome finish, polished finish, black finish, "Ford", "GM", etc. As long as they fulfill the above requirements, and mate to the booster, they'll do the same basic job, the rest is a choice on preference for finish and brand quality. When you buy a booster, master cylinder, and hose kit from us, we will make sure that they all fit with each other. If you choose a master cylinder that is different than stock, you may expect to adapt or re-flare a brake line or two to make it fit.
If your stock master cylinder is fresh, or if you have another one that you want to use with your kit, please note which one you will be trying to use in the comments section so we can make sure it will mate together with the booster - not all master cylinders have the same bolt spacing, rod length, or even fit in the Hydro-Boost.
Converting to the Hydro-Boost does not require you to change your proportioning valve. If you have made changes to your rear brakes, like a rear disc conversion, you will want to select a proportioning valve in your kit if you haven't changed that already. Generally, disc brakes need 1,200 pounds of pressure, and drums lock up at 600, so if you change rear drum to disc, and don't change the proportioning valve, your rear brakes will only get half the pressure and volume of fluid that they need. Your brake pedal will likely feel like it does it's normal application, but then continue to sink to the floor if you have a disc/drum proportioning valve on a disc/disc setup, because it is trying to fill up the caliper pistons but is not getting the job done in the normal pedal application. If you have disc/drum and don't have a proportioning valve installed, cutting the pressure to the rear brakes in half, the rear drums will just lock up every time you press the brake pedal, making it intolerable to drive. You would also change the proportioning valve if the one you have on there now is a few decades old, is crusty, and you want to put a fresh one on, or would like the added feature of adjustability.
The proportioning valve is offered by itself or with a bracket and pre-bent lines. The bracket and pre-bent lines are a best fit for a Wilwood master cylinder, if you pick a different master you may be able to manipulate the lines to work, but expect that they aren't going to be a direct fit. Many times the proportioning valve is not off the side of the master cylinder, but rather low on the firewall or down on the frame. It will make for the easiest plumbing job to install the new valve where the old one was, but it has an adjustable knob, so it may be hard to reach if installed on the frame for adjustment. Select the option with the bracket if you are trying to mount the valve off the side of the master cylinder, and with no bracket if you are going to mount it on the frame or firewall.
The Hydro-Boost will usually mount on the end of your brake pedal, which will be on the firewall for most vehicles and sometimes down on the frame on older vehicles. Some customers will do engine swaps, run large turbo intake tubes, or switch to air suspension that then gives them no room to mount a brake booster in it's stock location. If space is an issue, we can relocate the booster to the frame or bed/trunk area with a hydraulic slave cylinder, feel free to call if you have more questions about this, but it is very straight forward and we have workarounds for most every situation. The Hydro-Boost replaces the current brake booster, and unless you are building a show car or have made radical changes in the engine bay, it will almost always be mounting on the frame or firewall like the stock booster did.
Select "Replacing Stock Hydro-Boost" if you had a Hydro-Boost stock, and are replacing it with this new unit in it's current stock location. Select "Converting from Vacuum Brake Booster" if you will be replacing a stock vacuum booster with the Hydro-Boost in it's current stock location. Select "Hydraulic Remote Mount" if you are relocating the brake booster and master cylinder to the frame or bed/trunk area because of severe space limitations.
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