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That just about wraps up the Hydroboost installation. At this point, you should bleed the air from your power steering hoses. The procedure for bleeding the lines is here at the bottom of the page. Take your time and do a good job on it. Your pump will appreciate your efforts!
Next comes bleeding the brake lines. Although I had never done it before, I took Van's advice and bench bled the master cylinder before hooking it to the TJ's combination valve. It is not mandatory that you do it, but from what I witnessed, it sure does get the air out of the system a LOT easier.
To bench bleed, get some rubber hose that just fits over the end of the steel lines you bent (not the fittings, just the flared end of the line itself). Screw one end of the line into the master cylinder and slip the hose over the other end of the line. Note that you won't have these lines "routed" in the manner that you bent them for....just get them attached to the master cylinder in such a fashion that you can get to the other end. Now put the free end of the hose into the master cylinder as shown in the above picture. Do the same for the other port on the master cylinder. Fill both sections of the master cylinder with fresh brake fluid so that the ends of the hoses are completely covered (and then some).
Now, SLOWLY push the brake pedal (you can do it by hand if you wish) down as far as it will go and then release it. Wait about 5 seconds and repeat this process. After several minutes of doing this, you should notice that the bubbles that were coming out of the hose and up from the little ports inside the master cylinder have all but stopped. Congrats....your master cylinder is now bench bled and all the air that was in it is now gone.
Remove the two rubber hoses. Now reposition the lines so that you can connect the combination valve to the master cylinder. If it has been a while since you have flushed out the brake fluid in your vehicle (and it probably has), you can do a regular brake bleed at all for wheels. Once you get fresh clean fluid coming out at each wheel, you should be quite confident that you have gotten out any air that may have gotten into the system during your install and you'll have fresh fluid to boot!
The previous pics of the Hydroboost were taken during my first installation. The unit used at that time was a 3/4 ton model as I mentioned earlier. The picture above was taken after I got my system working correctly with the 1 ton Hydroboost. The hose connections are identical on both units. The major difference that you can see is the blue accumulator in the above picture. This accumulator stores a gas charge and fluid so that the brakes can be applied a couple of times even when the engine is not running (much like the vacuum booster will keep a couple of pumps available until the vacuum canister is emptied).
Here are the final results of my install....2600 PSI on the pressure gauge. Not too bad and that is right about where Van expected it to be. Actually, I get anywhere from 2200 to 2600 depending on my engine speed. With the engine just a little above idle, about 1500 RPM or so, I'll hit max pressure. Not too bad at all! These numbers are right in line with the other Jeeps that Van and I worked on. We were getting 2200 to 2400 PSI on a TJ and XJ respectively after installing 1 ton Hydroboosts on them.
As for real world testing, MikeW and myself went out to the same dead end highway and I did a couple of 60~0 MPH deceleration runs. As expected, my brakes are working much better now....or perhaps I should say that I finally have enough pressure to really lock up the brakes. Of course, locking the brakes is not the fastest nor safest way to come to a rapid stop. With the extra caliper pressure, my rear brakes are grabbing a bit more than desired and the resulting lock up causes the rear end to start to come around (normal when locking up the rear brakes). So, as I kind of suspected, I'll be picking up an adjustable proportioning valve to install in the rear line. This will allow me to set up the front to rear bias and prevent the rear lockup that I was experiencing. Just for grins, MikeW gave his TJ a try too. While he has the stock booster and proportioning valve on his, he also has a Ford 9" rear axle with drum brakes....and those drums are much larger than the TJ drums. He too has too much rear brake pressure as he locked up the rears all too easily during his panic stop.
I think that about wraps up this installation. When I get my adjustable proportioning valve for the rear, I'll add those details onto this write-up to make it a "complete" project.
Again, many thanks to Van for all of his help. It is
always great to work with a vendor that provides this level of customer service.
When you decide to put a Hydroboost on your TJ, tell Van you read about it here.
You are looking at about $825 for a complete kit (pump, Hydroboost, master
cylinder, hoses and adapters). If you already have a high flow pump, then
subtract $125 from the price. Van said he would do group purchases
starting at a minimum of 5 people which would drop the price by $100. By
the time you read this, pricing may have changed so don't hold me to the above
numbers. They were current when the write-up was done but most likely are