From researching the web, it seems like hydroboost coversions can have issues with return return fluid from when the brakes are actuated. Apparently Tee-ing into the power steering return line gives some hydrostatic resistance to flow from the hydroboost unit, which causes sluggish pedal return. It seems so critical in some cases that the orientation of the Tee is in question: return to the perpendicular leg or the in-line leg. Some have put another port on the power steering reservoir for a free-flow back.

Anyone else hear of this as an issue?

That is why the factory hydroboost systems have a second return inlet on the pump reservoir. You can either buy a pump for a diesel app, or I have seen people put a bulkhead fitting in the standard saginaw pump reservoir for a return.

My pump is one of these Saginaw units (http://www.jegs.com/i/JEGS/555/60701/10002/-1)from Jegs. The chrome bolt at the 10 o'clock position looked promising, but it is a blind hole I presume for mounting ease.

How hard is it to modify this pump? Does the housing come off so it can be drilled for the bulkhead? Does the fitting brase on or clamp with nuts? Is it hard to find the right spot?

Thanks...

http://www.chevelles.com/forums/showthread.php?t=254644

Check the above post out. Pete

It's easy to remove the reservoir from the pump. Remove the retaining bolts and outlet valve and pull the pump out.

The new return can be placed where convienient as long as it does not interfere with the pump mounting. Mocking it all up first to determine where the best location would be will make your life easier in the future. The return tube can be welded or brazed. On the first generation of my build I brazed a -6 male onto the can, and for a buddy's setup we brazed on a stainless tube.

The best way to do the return is into the tank. If the return from the booster is too close to the steering box return there is a possibility that fluid returning from the box will back-pressurize the booster return. This will cause not only a slow pedal return, but would apply the brakes on mine. Mine was set up with a "T" mounted directly on the box return, so feedback to the booster was direct.

There's some info on my website as well.

It is quite important to locate your additional spout in the correct location on the power steering pump reservoir. This drawing shows the only two correct locations. Right in the center on the back of the reservoir and roughly at the 7 o'clock position. (You can also go around the corner from the 7 o'clock position and place the spout on the side of the reservoir.)

http://i2.photobucket.com/albums/y38/JIML82/ReservoirSpoutLocations.jpg

It is important that the return flow has a chance to pool in the reservoir (and release any air bubbles) before being sucked into the pump intake. The above locations provide this pooling affect.

Be sure to use silver solder or weld the spout into position. Ordinary solder will melt under high steering temperatures.
Jim
Jim

Jim, that's fantastic! That's what I was looking for! I assume the housing is steel since you said "weld"... So would brazing a fitting also be a-ok? I haven't brased for a while :)

The dipstick on my pump cap has me put the fluid clear to the top of the housing, right below where the cylindrical neck attaches. That's way above the return ports(?) What do I do with that>

There are all kinds of Saginaw pump caps with various length sticks. There is probably a good chance that you don't have the original cap with the correct length stick. They will all interchange on the neck of the Saginaw pump reservoirs. You definately want some air volume in your reservoir. I just can't give you a good rule of thumb as to how much air.

Jim

This is the pump with original cap shown in the link above, from Jegs. Where do they come from, are they still being made, or are they all rebuilds?

You can also go to the parts store and buy a pump for a 76 G-series van (A-1 Cardone part # 20-8609) and it will have 2 returns already. It mounts right to the existing brackets. You will need to change the pulley which is offered by Dorman. I can give you that # also depending on whether you want a single or double groove. I'm not smart enough to know how to copy and paste the thread here, but I had some pics and info posted on the brake forum a while back. I had the slow release problem also, but I think it was insufficient bleeding rather than the tee installation. When I changed pumps I still had the problem until I bled it and drove it a 100 miles or so.

Danny

Danny, I need a keyway Saginaw, that's what my March pulley fits... Aren't keyway's the old school kind?

Danny, I need a keyway Saginaw, that's what my March pulley fits... Aren't keyway's the old school kind?

Yes, this van pump is the keyway design.

Danny

Thanks, Danny, we're on a roll...

So, here is one of those rascals with two return lines, the part number you provided: http://www.woodys-auto-supply.com/auto-part-details.asp?prod=A-1-20-8609 It looks like a little monkeying to get the lines shortened and re-aimed, but that's OK. Will a pump for a '76 system be the right pressure for my 68 steering box and a hydroboost unit?

Also, dumb question.... What's a G-series van? I am going to check for the pump locally first, and if I don't have all the specifics of that vehicle (year? make? model? displacement? auto? cigarette lighter? step bumper? etc? etc? etc?) for them to punch in the parts store computer, they will never find it.

That is a super price on that pump. Cheaper than what I paid here at the Carquest Dist Center. If you want to check locally, tell them you have a 1976 G-20 Chev van with a diesel engine. There will only be one for that application. This pump worked great on my 72 Chevelle as for as pressure and fittings. I cut the return spouts off before they make that last turn up the side of the reservoir. Be careful. They are welded to the housing for support. Search my threads and you'll see the pics of my installation. If I can help, let me know.

Danny

Just remembered! This pump does NOT have a keyway. It would still work with the correct pulley, but I took my original pump and put it in this double return housing and that way you can use the original pulley. I swapped for a 2-groove so I could run double belts.

Danny