All of the CUCV military vehicles are equipped with the Hydro-Boost™ System to power the brakes and the steering. The system is made up of the following items:

	High flow belt driven pump with two high-pressure outlets and two low-pressure inlets
	Hydro-Boost™ hydraulic brake booster
	Standard GM power-steering box
	Two high pressure lines with O-ring seals and two 1/4" ID low-pressure return lines

This system is used because the diesel engines do not make enough manifold vacuum to use the traditional vacuum-boost system. In this series of photos I'll be replacing the two high-pressure lines because as you can see from the picture below, they've both seen better days. One hose rubbed against the other and created a hole in the brake to steering-box hose. The pump to brake booster hose got caught up in the flex joint on the steering shaft and had to receive a band clamp patch for its almost mortal wound. Let's take a look at how the job is done.  Just click on the photo for a larger version and use your browser's BACK button to return to the page.  

From this photo you can see what a maze of hoses you'll find on the driver's side of a CUCV. Notice the fluid all over the hoses and the "southern construction" patch job right above the steering shaft.

Step 1  Before you do anything else, you need to disconnect both batteries completely. Then, remove the three 15mm bolts that hold the alternator in place and sit it off to the side. Now you have a clear view of the pump and all of the nuts and bolts which secure it to the block.

Step 2  The easiest way to get to the hose fitting on the back of the pump is to remove the pump. To do this you must first remove the 5-6 nuts and bolts and then work the alternator bracket off past the pump. Once it's clear you can simply roll the pump over and take off the hose.

Step 3  Now you can see why it would be easier with the pump off. When you try to unbolt just the hose, the other large bolt which retains the bypass valve in the pump tries to come off too. You can prevent this by holding it with a 1" wrench and breaking the hose loose with a 16mm tubing wrench. I would suggest replacing the low-pressure hoses too while you've got the whole truck tore down. My hoses were fairly new so I skipped that step. Now the tough stuff is over because the rest of the fittings are easily reached. It's just out with old and in with the new. NOTE: be careful not to over tighten the high-pressure hose fittings because you will destroy your brand new o-rings. Just tighten them up so they don't flop or leak.

Step 4  After you have the new hoses snugged up, put everything back together in reverse order. Make sure you protect your new hoses with plastic wire loom that the hose manufacturer usually provides. I bought mine from NAPA and they come with the loom and they are guaranteed for life too. Zip-tie everything in place as shown and top off your power steering fluid. To bleed the new lines of any air, put the front end of the CUCV up on jack-stands and start the engine. Then, slowly turn the steering-wheel from full right to full left several times. After that, shut down the truck and check the fluid level again. Repeat this process until the fluid level remain steady and you don't see any bubbles. Clean up and you're done. Good job!

NOTE: SteelSoldiers.Com has provided this information to you in order that you may have a better understanding of the Hydro-Boost™ System and how to service it. The above is a simplified shade-tree mechanic version of the repair procedure. If you do not feel comfortable doing the procedure, please seek professional help. SteelSoldiers.Com denies any liability for the use or abuse of the above information.