Jeep Hydroboost Braking System
The PROBLEM: Jeeps are notorious for poor stopping performance...
Then you add front discs, rear discs, larger tires, bigger axles with bigger brakes, lower gears, a bigger engine, and so on and so forth, and before you know it, the brakes become almost useless with the pressure and power generated by the original stock braking system.
The SOLUTION: Vanco has devised a system that has worked wonderfully on all prototypes it has been tested on. It is a very easy to install Hydroboost system that bolts right up and uses your power steering pump, instead of engine vacuum, to provide power assist to the brakes. It can be used to convert manual brakes to power brakes, to upgrade factory power brakes, or to work the bigger brakes on that stronger axle you are swapping in.
The power of the Hydroboost allows the system to incorporate a larger bore master cylinder than is possible with a vacuum assist, which produces more brake clamping pressure and, at the same time, a higher brake pedal. (Vacuum systems require about an inch and a half of pedal travel before they begin to work.)
The booster is very slim, only about 4 1/2” in diameter, as opposed to the 9”-10” diameter of vacuum boosters, so, if you are concerned about space…worry no more.
This booster gives tremendous power, whether you are going 5 mph or 100 mph. It is never too sensitive, and never lacking in power.
The Vanco Hydroboost System
*Available as a complete kit or separate individual components
What you will need to provide:
Fluid. What kind you ask. Different people will tell you different things. GM, whose vehicles this system is used on, recommends GM Power Steering Fluid, Part No. 1050017, but other brands of “power steering fluid” will also work. The Chilton Jeep Manual recommends DEXRON II automatic transmission fluid. Others will recommend Type F automatic transmission fluid. The choice is yours, any of the above will work fine. (Hint, if you have an automatic transmission, you could get away with carrying only one type of spare fluid to cover both.)
How much fluid will you need? If you are doing a full blown system, a Hydroboost, new power steering pump, a new steering box, a cooler, and a filter, you will need approximately 3 quarts.
DOT 3 Brake Fluid for the new master cylinder.
A Cooler if so desired. (Usually the rubber hose, clamps, and mounting accessories come in kit form with the cooler.)
A Filter (highly recommended). Available from Vanco.
NOTE: If you are upgrading from manual steering, you will additionally need to obtain
- a power steering box
- a power steering box return line
- a power steering pump mounting bracket
- depending on the model year, a compatible steering shaft or conversion coupler for the steering box input shaft
Removal of the Old System
1. Remove your existing power steering lines from the steering box and drain the steering pump.
2. Remove the other end of the lines from the steering pump.
3. If the existing return line has the rubber hose attached to the metal tubing with a hose clamp, remove the hose clamp and discard the rubber hose. If the metal and rubber portions are crimped together, cut the steel tube just before the connection to the rubber hose.
WARNING: IT IS IMPORTANT TO USE A TUBING CUTTER, AS SAWING WILL LET METAL PARTICLES IN THE TUBE.
4. If replacing the power steering pump, remove the old pump and the portion of the mount that is bolted to the pump. (When’s the last time you replaced your belts? Now would be a great time to do so.)
5. Remove the vacuum line from the existing brake booster and engine.
The vacuum line will no longer be used, so you will need to plug the vacuum connection at the engine.
6. Remove the brake lines from the master cylinder.
WARNING: BRAKE FLUID WILL DESTROY ANY PAINT IT COMES IN CONTACT WITH!
7. Remove the cotter pin and disconnect the booster rod from the brake pedal.
8. Remove the 4 bolts through the firewall, and remove the existing master cylinder and power brake booster as a unit. (It helps to have another person to hold the nuts/bolts from turning inside the Jeep.)
Assembly of the New System
A. Bench Bleeding New Master Cylinder
1. Remove the new master cylinder from the Hydroboost.
2. Clamp the master cylinder in a vice and fill both reservoirs ¾ full with DOT 3 brake fluid and remove outlet hole plugs.
3. Use a wood dowel, blunt drift pin, or something similar, to push the piston ¾ of the way in, plug both outlet holes with your fingers, and then release the piston.
WARNING: DO NOT OVER-DEPRESS THE PISTON!
(I know, how are you supposed to know how far ¾ is without depressing it all the way?)
4. Repeat Step 3 until fluid streams steadily out of both outlet holes with no air or sputtering.
5. Put the plugs back in the master cylinder outlet holes.
6. Remount the master cylinder to the Hydroboost.
B. Mounting the Hydroboost and Master Cylinder
WARNING: REQUIRES 2 PEOPLE TO PREVENT DAMAGING THE NEW EQUIPMENT
1. While one person holds the Hydroboost and master cylinder against the firewall, the second person puts the Hydroboost pedal rod on the clevis pin on the brake pedal. Do not install the washer and retaining pin yet.
WARNING: DO NOT OVER-DEPRESS THE HYDROBOOST PEDAL ROD, AND DO NOT PUT PRESSURE ON THE ROD BY ALLOWING IT TO SUPPORT THE WEIGHT OF THE HYDROBOOST AND MASTER CYLINDER
2. Together, as a team, install the nuts and bolts to secure the Hydroboost and master cylinder to the firewall.
3. Using the slots in the Hydroboost mounting bracket, adjust the assembly up or down so that the pedal rod goes into the Hydroboost straight, and not at an angle.
WARNING: MISALIGNMENT OF THE PEDAL ROD WILL CAUSE PREMATURE FAILURE OF THE HYDROBOOST
4. Tighten the 4 bolts securing the assembly to the firewall.
5. Check to make sure there is a little slack in the brake pedal. The Hydroboost pedal rod should not be depressed at all, and the brake pedal should have a little up and down jiggle.
WARNING: FAILURE TO ALLOW SLACK IN THE PEDAL ASSEMBLY WILL RESULT IN CONSTANT BRAKE ENGAGEMENT AND DAMAGE TO THE BRAKE SYSTEM
If proper slack cannot be obtained, contact Vanco at (323) 563-1588 about additional spacing schemes that are available. DO NOT OPERATE UNTIL CORRECTED.
If you’re not replacing your power steering pump skip 6-9
6. Remove the pulley from your old power steering pump. This takes a special puller. Using anything other than the proper tool will damage the pulley.
7. Install the pulley on the new power steering pump either with the puller, or by pressing it on with the bolt, nut, and washer supplied. Screw the nut onto the bolt, put the washer on the bolt, then put the bolt through the pulley and thread it into the end of the power steering pump shaft. Back the nut off the bolt to press the pulley onto the shaft. (Greasing the washer makes this operation go smoother.)
8. Remove the mounting brackets from your old power steering pump and install them on the new pump. One of the bolts on the old pump has a shoulder on it to properly position the pump. The new pump does not have this shoulder. You can either switch the bolts, or find some washers to put on the new pump to simulate the shoulder.
9. Install the new pump and belt on the engine.
WARNING: USE CARE IN HANDLING THE POWER STEERING PUMP, THE RETURN LINE NIPPLE IS VERY EASY TO DAMAGE.
ALSO,DO NOT PRY AGAINST THE RESERVOIR TO TIGHTEN THE BELT AS DOING SO WILL DAMAGE THE PUMP. USE A 3/8” RATCHET IN THE SQUARE HOLE IN THE MOUNTING BRACKET TO TENSION THE BELT.
C. Plumbing the Hydroboost System
1. Lubricate the “O” rings with clean power steering fluid and install one of the supplied AN adaptors in the output fitting of the steering pump (there is only one hole the fitting will fit).
WARNING: DO NOT OVERTIGHTEN. DO NOT EXCEED 20 FT. LBS.
Tip: tighten approximately ¼ turn after the “O” ring makes contact.
The fittings are designed to allow the lines to swivel slightly even after properly tightened, and over tightening can result in failure of the “O” rings.
2. Connect either end, doesn’t matter, of the shorter hose to the AN adaptor on the steering pump.
3. Lubricate the “O” rings with clean power steering fluid and install one of the supplied AN adaptors in the engine side fitting on the Hydroboost.
4. Connect the other end of the short hose to the engine side adaptor on the Hydroboost.
5. Lubricate the “O” rings with clean power steering fluid and install one of the supplied AN adaptors in the forward/engine side fitting on the steering box.
6. Connect the hooked (180 degree bend) end of the longer hose to the forward/engine side adaptor on the steering box.
7. Lubricate the “O” rings with clean power steering fluid and install one of the supplied AN adaptors in the fender side fitting on the Hydroboost.
8. Connect the other end of the longer hose to the fender side adaptor on the Hydroboost.
9. Connect one end of the rubber return hose to the nipple on the Hydroboost with a supplied hose clamp.
10. Route the rubber return hose down to the power steering pump. Figure the best route and where you may want to tie the hose for support and to keep it away from sharp, moving, or hot things before cutting. Cut the hose and attach it to the steering pump nipple with a supplied hose clamp.
WARNING: THE RETURN LINE NIPPLE ON THE STEERING PUMP IS NOT VERY SUBSTANTIAL SO HANDLE WITH CARE.
11. Reinstall the metal end of the original return line on the steering box. The original line may have had a clamp supporting the line from the frame. Reattach this clamp if present.
12. Connect one end of the remaining rubber return hose to the end of the original steering box return line with a supplied hose clamp.
13. Next in line would be a cooler and/or a filter, in that order, if desired. Neither is supplied with the kit, but the filter is highly recommended by Vanco and is available from them.
14. Next, figure out the best location to cut the return line from the Hydroboost to the steering box to insert the supplied “T” fitting. (The “top” of the “T” MUST be in line with the Hydroboost return line, and the “stem” of the “T” will provide a connection for the other end of the rubber return hose coming from either the steering box return line, cooler outlet, or filter outlet, depending on what components are used.)
15. Connect the other end of the rubber return hose from the steering box return line, cooler outlet, or filter outlet, as the case may be, to the “stem” of the supplied “T” fitting with a supplied hose clamp.
D. Connecting the Brake Lines
1. Reconnect the brake lines that were disconnected from the original master cylinder to the new master cylinder.
The brake line that goes to the front brakes must be connected to the larger of the two reservoirs on the master cylinder, which is designed to serve higher capacity front disc brake calipers.
The brake line that goes to the rear brakes must be connected to the smaller of the two reservoirs on the master cylinder.
WARNING: THE RESERVOIRS ON THE NEW GM MASTER CYLINDER ARE ARRANGED OPPOSITE OF THE ORIGINAL JEEP MASTER CYLINDER, WITH THE LARGER RESERVOIR FORWARD.
THE BRAKE LINES MUST BE REVERSED FROM THEIR ORIGINAL ORIENTATION.
In most cases, the smaller line with the smaller fitting is the front brakes and goes to the larger reservoir, and the larger line with the larger fitting is the rear brakes and goes to the smaller reservoir.
If you find the fittings on your brake lines do not fit the new master cylinder, adaptors are available from any good auto parts store.
Although you should only have to bleed at the master cylinder connections, and it should not be necessary to bleed at the wheels, if you are not certain you have the lines hooked up correctly, there is a sure fire way to check. Just bleed down at the calipers and/or wheel cylinders. When bleeding the front brakes, you should see the fluid level drop in the larger reservoir, and when bleeding the rear brakes, it should drop in the smaller reservoir.
E. Bleeding the Brakes
1. Find your helper again. Have them get in the Jeep and work the brake pedal.
2. Back off BOTH the brake line connections on the master cylinder one full turn.
3. Have your helper push the brake pedal slowly to the floor and hold it there.
4. Tighten BOTH brake lines and have your helper release the brake pedal.
Repeat Steps 2-4 until the brake fluid streams out of BOTH ports without “sputtering”.
WARNING: AGAIN, WATCH OUT FOR THAT BRAKE FLUID, IT WILL DESTROY YOUR PAINT!
F. Bleeding the Hydraulic System
1. Fill the power steering pump reservoir to the top.
WARNING: DO NOT START THE ENGINE AT THIS TIME!
2. Remove the coil wire and crank the engine for several revolutions..
3. Turn wheels from stop to stop TWICE
4. Check the fluid level in the reservoir and add if necessary.
5. Repeat Steps 2 and 3 until fluid level does not drop.
6. Replace coil wire and start engine.
7. Turn off engine and depress brake pedal 4 or 5 times to relieve accumulator pressure.
8. Check fluid level and add as necessary.
9. Start engine and turn wheels from stop to stop.
10. Turn off engine and depress brake pedal 4 or 5 times to relieve accumulator pressure.
11. Check fluid level and add as necessary.
WARNING: IF AT ANY TIME THE PUMP GROWLS OR FOAMING OCCURS IN THE FLUID, TURN OFF ENGINE, WAIT FOR 1 HOUR AND CHECK FLUID LEVEL ADDING AS NECESSARY.
If continued bleeding does not work, fill power steering pump reservoir to top, start engine, and watch fluid level in reservoir. On occasion, the system will draw the fluid down to a point where it is sucking air. If this happens, install a piece of clean new 1 1/2” diameter x 12” - 18” long radiator hose to the neck of the power steering pump reservoir with a hose clamp. Fill the hose about half full, and restart the engine. The hose will in essence increase the capacity of the reservoir and keep the system from taking on air. After all the air is bled out of the system, the hose can either be removed, or left on to provide increased fluid capacity. The red rubber cap that comes on the new steering pump can be used to close the end of the radiator hose, but it will be necessary to punch a small hole in it to provide venting.
Vanco Power Brake Supply
9738 Atlantic Avenue
South Gate, CA 90280
Phone: (323) 563-1588
Web page: vancopbs.com
Don’t hesitate to call “Van” with any questions or problems!