Changing to a hydroboost setup on a 3rd gen gas truck

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chrisp2493

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There are some old threads on other forums about this, but figured I’d throw one up for people who haven’t heard of it. This isn’t my idea, many people have done it, but I took lots of pictures while I did mine. Here is what I used

I got a hydrobooster off a 3rd gen Cummings truck. I got it for $60 at a local wrecking yard. Unfortunately they cut off the lines instead of unscrewing the fittings, so I sourced them elsewhere
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I found a guy parting out another Cummings truck, so I bought the 3 main hoses and fittings from him for $80. There are 3 lines, 2 bough pressure lines going to the power steering rack and to the power steering pump. And 1 low pressure return line, it’s just a 3/8” rubber tube. You can get these lines made at a store like NAPA or somewhere similar, but I needed up having a hard time dealing with the guy at the counter and decided to just buy them from the cummins truck. All the hoses fit as far as the length for me.

To remove the vacuum booster, unplug the electrical connector on the brake fluid reservoir. This plug will go straight into it, no change needed. Disconnect the two brake lines, these will also screw into the new hydrobooster with some slight stretching.
Disconnect the air vacuum hose. The manifold will need plugged or you’ll have a vacuum leak.
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Inside the truck by the brake peddle, there is a safety clip that holds the pushrod to the brake peddle. Remove that and the peddle will swing free. Then there are 4 15mm nuts to remove and the booster will be free. It helps to have a long ratchet extension and a socket knuckle attachment. Then the booster will pull right off the truck
39744969301_d2cc2fb620_z.jpgUntitled by Chris Pearce, on Flickr
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The booster will fit right into the old holes, everything lines up. Make sure when you put the booster in, the pushrod is on the right side of the peddle. I had to take the booster back out and line the pushrod up because it got caught on the opposite side of the peddle arm and there wasn’t enough room to wiggle it over. It helps to have a second pair of hands to line it up easily. One small issue I ran into was after it was all tightened up, the peddle was about 1/16” of an inch further away and the brake switch wasn’t shutting off the brake lights correctly. I don’t know if I accidentally bent the switch bracket alittle, or if the pushrod is slightly longer. I just added a small spacers to the peddle to push the brake switch in alittle further to work correctly. Again, not sure if that is the case for everyone. In my case, I just drilled a 5/16" hole and put a 1/4" bolt and nut through it, That will hold the brake switch in the off position pretty well
25873837338_4b5169c1eb_z.jpgUntitled by Chris Pearce, on Flickr
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Now for the lines. The return line needs to be T’ed into the power steering cooler line that goes from the cooler to the reservoir. The cooler line is 5/8” inside diameter, the return line for the booster is 3/8” ID. I pieced these parts together at NAPA in a pinch, cost me over $30 for the Parts. You might find a pre-made T cheaper somewhere else. It’s a low pressure line so barbed ends and hose clamps work fine.
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The top line coming off the booster goes to the power steering pump. To retain the power steering pressure sensor, you have to splice into the factory hard line. I cut the factory line about 1” above the sensor and installed a 3/8” flared union. It’s is NOT a compression fitting, it’s actually flared. This is a high pressure line eebf61ef4386a414fbc09169b5371b75.jpg
I cut the booster line to fit, flared that line and screwed it together
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The bottom line off the booster goes to the power steering rack. It screws into the lower hole in the power steering rack. The Cummings line fit right in for me, that was pretty simple.

It was recommended to me to use ATF 4 transmission fluid in the power steering rack after this changeover. I’m not really sure why, I think it has to do with how it holds up in the winter and cold temperatures. I actually would love some more info on that, but that’s what I used. And just standard brake fluid in the lines. You will have to bleed the brakes after this.

I’ve only driven a few times since the switch, but the brakes are WAY more solid then the air system. You barely push the peddle to brake now. It feels rock solid. I haven’t had the chance to really test them out. Now in case you are wondering, if for whatever reason your truck stalls, you will STILL HAVE BRAKES!! I think there is a check valve in the system that keeps some pressure for a few brake applications. When I was tuning my new cam, I had the truck stall will driving a few times, so I can personally attest to them still working when the truck is dead.

I’m am really pleased with the outcome. On top of solid brakes, there is so much more room in the engine bay. It’s very easy to reach the back valve covers and spark plugs now, it was worth it just for that. It only cost me about $200 all said and done
 
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xtremewlr

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The power steering on my 2004 uses ATF+4 already. I thought all the G3 Rams did.

Nice write up. Definitely something I want to do.
 
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chrisp2493

chrisp2493

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Ok thanks for the info. I was putting regular power steering fluid in the old setup, but I didn’t know these were different. I had never heard of using atf 4
 
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chrisp2493

chrisp2493

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HemiLonestar

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I got a hydrobooster off a 3rd gen Cummings truck. I got it for $60 at a local wrecking yard. Unfortunately they cut off the lines instead of unscrewing the fittings, so I sourced them elsewhere

I found a guy parting out another Cummings truck, so I bought the 3 main hoses and fittings from him for $80. There are 3 lines, 2 bough pressure lines going to the power steering rack and to the power steering pump. And 1 low pressure return line, it’s just a 3/8” rubber tube. You can get these lines made at a store like NAPA or somewhere similar, but I needed up having a hard time dealing with the guy at the counter and decided to just buy them from the cummins truck. All the hoses fit as far as the length for me.

Inside the truck by the brake peddle, there is a safety clip that holds the pushrod to the brake peddle. Remove that and the peddle will swing free. Then there are 4 15mm nuts to remove and the booster will be free. It helps to have a long ratchet extension and a socket knuckle attachment. Then the booster will pull right off the truck

The bottom line off the booster goes to the power steering rack. It screws into the lower hole in the power steering rack. The Cummings line fit right in for me, that was pretty simple.

Nice write up, two questions:
1. What's a peddle?
2. What's a cummings?
 
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chrisp2493

chrisp2493

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Nice write up, two questions:
1. What's a peddle?
2. What's a cummings?
Haha I wrote this up at 7:30 in the morning while I waited to leave work early. I’m surprised that’s the only typo you found
 

HemiLonestar

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Haha I wrote this up at 7:30 in the morning while I waited to leave work early. I’m surprised that’s the only typo you found
The cummings one always gets me because with all the myriad hats I wear in this line of work, diesel mechanic is one of them. Cummins dammit lol! Peddle is actually word, just not the pedal you meant lol.

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chrisp2493

chrisp2493

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The cummings one always gets me because with all the myriad hats I wear in this line of work, diesel mechanic is one of them. Cummins dammit lol! Peddle is actually word, just not the pedal you meant lol.

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I see cummins a few times in there. I think the autocorrect got me haha

Since you do diesel mechanic, do you know if the hydrobooster is the same on the 2nd gens? I had a guy asking cause he found one cheap
 

HemiLonestar

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I see cummins a few times in there. I think the autocorrect got me haha

Since you do diesel mechanic, do you know if the hydrobooster is the same on the 2nd gens? I had a guy asking cause he found one cheap
Only way to known for sure is to bounce part numbers...should probably caveat that with 'marine diesels' lol. I've worked on land based ones but its don't know if those parts are the same.

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HemiLonestar

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It's been done so many times and there are so many write ups on so many forums you should be absent find a pretty good p/n list.

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