Where is Bill usn-1's main Hydroboost / hydraboost thread?

[VooDoo]

I didn't see it in the BP Knowledge Base under Brakes. If I search on hydroboost or hydraboost in the title for threads started by Bill usn-1 in the Tech forum, I don't get any hits. There are so many hydroboost threads out there now... I want to start with the main one and go from there.

Also, is there a "short list" of ALL parts with part numbers for NEW items already compiled that I can just print off for IH FULLSIZE conversion?

Thanks for pointing me in the right direction.

[jauringer]

Here ya go. It's on just Internationals

Hydroboost conversion

[VooDoo]

Originally Posted by jauringer

Here ya go. It's on just Internationals

Hydroboost conversion

Awhaa! I did see that link in another thread, but thought the original was here. Thx.

[shovelhead91701]

I had a problem visualizing the routing of the entire system and sent a PM to Bill... he straightened me out on it(thanks Bill) but I thought I would draw out a really simple drawing of the components and routing of the hoses. Hope it helps someone else!

[Bill usn-1]

The confussion is normally in the use of "return" line.
The HB has a pressure in and a pressure out and a return which is the smaller barb fitting.

the "return" should always go thru the straight portion of the T with the PS return on the leg of the T.
Also use the preformed brass T from the sprinkler section of your home store and not a standard brass NPT- T and fittings screwed together. The ID is a little smaller on the NPT fittings.

[jauringer]

Here's a better diagram. It's directly from Bendix Tech Manual. (Disregard the Master cylinder hookup. The front brakes may be the back connection on the one you use)




The PS box always pushes fluid through the return, you don't want to block or create back pressure by running it into the wall of the "T" fitting. The hydroboost only returns fluid when the brakes are applied.


Additional Bendix troubleshooting/repair documentation is attached. Additional diagrams are included.

[shovelhead91701]

All right Jauringer.... I see how it is. You just couldn't let me be proud of my awesome technical diagram! Seriously though, thanks for the better pic. That should help people a lot more than my half arsed attempt at technical drawing.

[Tom Mandera]

Originally Posted by Bill usn-1

the "return" should always go thru the straight portion of the T with the PS return on the leg of the T.

I'm with Jauringer on this one, too, Bill.

Especially if you run a cooler, like I do.

I just did this last week.

I made two mistakes.

First, the HB ran to the "straight through" side of the T, and second, I THEN put the cooler inline before it went back to the pump reservoir.

I may have had better luck with the T at the end of the line, just in front of the reservoir - I didn't think it mattered at the time, but it does.

I eliminated the T by running the HB directly back to the pump (I welded an extension on the pump neck with a fitting on the side) and all is well.

How did I determine it was "wrong" you ask?

With the engine off, I could push the Scout.

Turn the engine on, and the slight back pressure from the steering box and coolers would cause the HB to auto-apply.

I thought they were dragging.. but when I drove it out of the shop into the slightly sloped driveway, and it sat still idling in neutral, then shut it off and it immediately coasted forward I KNEW I had a problem, and it was the hydroboost.

Fortunately, a quick re-route and I was in business.


So, either try the "T" with the straight-through on the steering box, OR put the cooler before you T the HB return in, OR best yet, just run the HB direct to the reservoir.

[Bill usn-1]

Per the write up....
The cooler goes on the PS side only.
Adding it to the HB line only adds more resriction to the return line and causes the HB to apply the brakes on it's own!!!
Why put a cooler in a line your trying to reduce the restriction on by routing it on the straight side of the T?

it's all been covered!
Every wrong way to install it has been done.

[Tom Mandera]

Originally Posted by Bill usn-1

Per the write up....
The cooler goes on the PS side only.
Adding it to the HB line only adds more resriction to the return line and causes the HB to apply the brakes on it's own!!!


Why put a cooler in a line your trying to reduce the restriction on by routing it on the straight side of the T?

When I bought the Scout, the HB was already installed.

I thought I would make it better by installing a cooler. I've run front lockers before with power steering and always add one (and now two!) coolers. On this Scout, I have lockers front and rear, wide tires, hydroboost, power steering, oh, and hydraulic assist to all make the power steering fluid hot and smokey.

I did not, however, have a good idea as to where the cooler should be installed in the line - I'm not used to having so many return lines all over the place.