PS pump questions

[k5blazerguy]

My power steering pump isn’t happy lately and am looking to replace or upgrade.
I was tryin to find info online about a better replacement option for my 79 blazer. I have a pump that has a remote reservoir from an 80s 454 suburban I parted out years ago.
And also, I’m getting a 5.7 motor tomorrow that has a serpentine setup from a 93 silverado that I planned to use on my blazer. I think it has a pump on it as well. So hopefully that pulley would work.
Is the pump with the remote reservoir that came on the big block suburban any better than what I have now? (I wouldn’t use that pump of course, I would get a replacement on rock auto and use as a core)...... Or is it any difference to replace my pump with the same and put the serpentine setup on it?
I know the fittings may be different and that’s another thing I’m worried about.
I just don’t know much about the pumps with remote reservoirs.
just looking into my options before I purchase a new PS pump.
oh, and I’m running 37s on 24 bolt H1s if that helps. Thanks.

 

[TreeFarm]

There are only a few type of power steering pumps. Fewer if you stick with saginaw style ones. the saganaw P series pump Is what came stock in your 79. It also came stock on that 93 silverado as well as that 80s 454. They still use the same pumps today on trucks. They are all the same pump with different reservoirs on them. The one in your 79 may be slightly different though. in 79 or 80 the auto industry switched from SAE inverted flare fittings to metric o ring fittings. but that's just the pressure fitting, those fittings interchange between all of the pumps. Companies like PSC will sell you a hot rodded pump with higher flow and pressure, but its still the same p series pump with their modifications.

The remote reservoir will allow you to use a lager reservoir for more fluid volume. Larger fluid volume always makes a hydraulic system better.

I have always just ran a stock pump or parts store pump with a good warranty. The Trucks Ive built on this site had a stock 200K mile pump on them. My jeep has a junk yard Saginaw TC pump in it, will be getting a junk yard CB pump when it dies. all of those are on 37s and were daily driven.

CB style pumps are the modern "best" pump. better flow, and pressure not too expensive. Not a bolt in replacement though.

This thread will teach a lot about PS pumps

 

[6872xtc]

I would try one of the used pumps before buying one. And the remote reservoir one would be good if you can mix it with the serpentine belt system.

And you will want to check your engine to see if it has the all of the bolt holes in the passenger side head for the serpentine bracket. I had to drill and tap one into a '72 head to install serpentine.

 

[k5blazerguy]

Thanks for the info!

If having more fluid helps I’d like to use that pump. But I may try the pump on the motor coming in today and see if that works too. Lol.
So if the pressure fitting is different on the back of the pump, what is best option to make it work? I don’t think I have the o rings.
my block should have the holes for serpentine, I have a 305 87-95 gen.
I’m acquiring a 87-95 gen 350 engine today and debating how to rebuild that one for the blazer. I definitely need more power. I’m squeezing all I can outta this 305.

 

[TreeFarm]

Thanks for the info!

If having more fluid helps I’d like to use that pump. But I may try the pump on the motor coming in today and see if that works too. Lol.
So if the pressure fitting is different on the back of the pump, what is best option to make it work? I don’t think I have the o rings.
my block should have the holes for serpentine, I have a 305 87-95 gen.
I’m acquiring a 87-95 gen 350 engine today and debating how to rebuild that one for the blazer. I definitely need more power. I’m squeezing all I can outta this 305.

If your pump is sae and not metric you will just need to swap the outlet fitting to the one that matches your hose. They just unscrew from the back of the pump. I have attached a picture of one.

All of the pumps that you have are the same. so it doesnt matter what one you use as long as its not burned up. The reservoirs are what is different. IF you want to use the remote reservoir one, don't think you are stuck with that pump. You can simply take a different pump and put it in that reservoir. I have attached a picture of what the actual pump looks like without the reservoir attached. As for serpentine or v belt pulleys. That's just a matter of swapping the pulley from one to the other. The pump shafts should be the same diameter, but don't quote me. measure them to be sure.

 

[TreeFarm]

Here is the difference between SAE inverted flare and metric o ring

Pictured is actually metric inverted flare but they look the same.

 

[k5blazerguy]

If it’s just swapping the connector on the back I may just try this pump. And do the serpentine swap at the same time. My motor just got here. I’m guessing I may have to replace the water pump too for serpentine I think I read that it spins opposite way for serpentine.

 

[TreeFarm]

yes, serpentine systems use reverse rotation pumps(smooth back side of belt pulley) vs regular rotation on v belts.

 

[Ned Kelly]

TreeFarm...good read on the link you posted.
Interesting point on running a 1/2" return line instead of the 3/8" that was the previous norm. I knew cavitation was bad, and the article addressed this in a nice simple explanation....and seems like the 1/2" return line would be an must have and easy way to address the issue.

“So why did all your pumps die prematurely?” I have a theory about this, too. Back when I ran these pumps I was using a 3/8 ID return line. I didn’t know any better. Apparently neither did the aftermarket guys though because I asked some about it on more than one occasion and they said it was OK. It’s not and they recommend at least ½ now. I was choking my system off badly and it is my theory that the pumps were cavitating and/or building excessive heat because of it.

 

[TreeFarm]

TreeFarm...good read on the link you posted.
Interesting point on running a 1/2" return line instead of the 3/8" that was the previous norm. I knew cavitation was bad, and the article addressed this in a nice simple explanation....and seems like the 1/2" return line would be an must have and easy way to address the issue.

“So why did all your pumps die prematurely?” I have a theory about this, too. Back when I ran these pumps I was using a 3/8 ID return line. I didn’t know any better. Apparently neither did the aftermarket guys though because I asked some about it on more than one occasion and they said it was OK. It’s not and they recommend at least ½ now. I was choking my system off badly and it is my theory that the pumps were cavitating and/or building excessive heat because of it.

This is where a larger reservoir comes in to play. If you are cavitating a pump because your return(tank) lines aren't large enough. Then you do not have enough fluid in reserve for the system. Your return lines do not feed the pump, the reservoir feeds the pump. You should have enough fluid reserve to keep the pump happy under full use, Max fluid volume in the system. Think steering ram extended, steering box extended(internally), brakes pressed if you have hydro boost. In the industrial world its usual for the reservoir to hold 3 times the capacity of the system, so if your system uses 1 gallon to fill components and lines, you would have 3 gallon reservoir. This is over kill for the auto world. At a minimum your reservoir needs to hold enough fluid to fill your entire system at its largest state(rams extended) and have some reserve, but still be large enough to hold all of the fluid when your system is at its smallest state (rams retracted.) Fluid cant compress so fluid coming out of the pump is equal to fluid going back into the reservoir if the system is static. Return is slightly less as ram volume increases and so on. A larger reserve of fluid feeding the pump with enough head pressure will fix this.

I think the common "norm" for PS lines in the off road world is now -8 feed and return which is 1/2" like you quoted above. The Stock PS lines in the auto industry are 3/8 feed and return. The PS system I just built for my jeep is -6(3/8) feed and return with -10 or 5/8ths feeding the pump from the reservoir.

 

[Ned Kelly]

I was looking at ORD's hydro-assist, I see .......
We use a #12 feed into the pump and #8 return line coming back from the steering box, these bigger lines help free up the system and let the pump flow more. The higher flow means the system reacts faster and leads to faster steering. Note that the bigger feed and return are only available on the '80 and newer o-ring style parts. If you have a '77-79 truck, you can simply order the '80 and newer parts and they'll swap right on other than a new pressure hose from a parts store.

https://www.offroaddesign.com/ord-spec-hydraulic-assist-system.html

 

[Wes Harden]

So I put a Saginaw pump on a ford Fe motor, power steering, and Hydra boost. The Thomson pump couldn't do both.
I grab a remote reservoir can from an Astro van. Used an aftermarket reservoir, @ 2 quarts, with 1" hose between the 2. Works great.