Saginaw PS Pump Upgrades [Archive]

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drummond

01-21-2008, 07:52 PM

After installing larger tires, lower gears, and lockers, I found that the stock power steering setup was not up to the task of handling the job that I need it to. This summer I upgraded my power steering box to a Jeep J-20 box with a 3.5" Bore, instead of the standard 3" bore found on most CJ's and other Jeeps. This box had a lot more power than stock, and could turn the tires much easier. However, I found that when I was in the rocks, and applying a lot of stress to the power steering (trying to turn up 2.5'-3' ledges) that the stock power steering pump was just not up to the task of moving the required fluid to the box. Today I decided that it was time to change that.

I had several options on which I could do to increase my power steering pump capabilities. I could buy a new box, such as an AGR...I could go to a junkyard and pay money for something else that MIGHT be better.....or I modify the box that I currently have. After doing some research, I found that it would be best to just modify the box I have...being the cheapest option, and I should be able to increase the volume/pressure by good amounts.

I started off with my stock PS pump located on my Jeep.
http://img.photobucket.com/albums/v602/drummond/100_1080-1.jpg

I disconnected the lines going to it, and unbolted the brackets. It will be easier to work on the pump with it removed out of the vehicle, however, I suppose you could leave it in if you wish. When you removed the high pressure line, you will see the main fitting located beneath it. You will need to unbolt this, IIRC I needed a 1" socket.
http://img.photobucket.com/albums/v602/drummond/100_1082.jpg
http://img.photobucket.com/albums/v602/drummond/100_1086.jpg
When you removed it, the main fitting looks like this
http://img.photobucket.com/albums/v602/drummond/100_1088.jpg
The part that is located directly behind it is called the flow piston, and it looks like this
http://img.photobucket.com/albums/v602/drummond/100_1089.jpg
The Piston spring is located behind this, and it looks like this
http://img.photobucket.com/albums/v602/drummond/100_1090.jpg
Here is the order in which they are removed
http://img.photobucket.com/albums/v602/drummond/100_1087.jpg

The first step for upgrading the capacity of the pump is to drill out the main fitting (part #1). I found that this increases pump flow from idle to low rpm's. My stock hole size was .125" and I drilled it out to .1825". I have read that it is best to not go much larger than that.

The second step to this process is to take the flow piston, and "unbolt" it. There is a small nut on the end of this. You can put it in a vise to unbolt it, as the metal compound is extremely hard. When you remove the nut, there are several pieces that are located inside the piston.
http://img.photobucket.com/albums/v602/drummond/100_1091.jpg
Going from left to right they are the, piston housing, spring, limiting stud, BB, shim, and end cap. I have read that some boxes do not have shims, however most generally do. You will want to remove the shim, before you put it back together, and then you can clean everything out. while you have this taken apart. By removing the shim you are increase the pressure...allowing a higher pressure box.
I read that if you discover down the road you still want more pressure, you can put a 3mm washer down the piston housing, and grind down the limiting stud to still allow pressure through the housing. However, this increases the pressure of you PS system dramatically, and can blow seals if you go to far. So you will want to do this in steps...that is why I havent done this yet.
After you remove the shim, there is one more thing that I have found that you can do to improve your box. Some people say that it makes a difference....others do not feel it really does. Anyway, I went ahead and did it. You can take your stock piston spring, which typically has a length of 1.875"-2" and extend it up to 2.5". I extended mine to around 2.25" or so
http://img.photobucket.com/albums/v602/drummond/100_1094.jpg

After this step, you can put everything back together. I found that it was a good time to sand down the box, and give it a coat of paint as well. This is how it should go back together, with the removed shim, bored out main fitting, and extended spring in order of how they should go in the box.
http://img.photobucket.com/albums/v602/drummond/100_1096.jpg

I bolted everything back up, and blead out my PS system. I found that I had quite a large increase in PS power, especially at low rpms. The Jeep's RPM's always seemed to drag down and the power steering system would slightly whine when I turned the 36's on dry pavement. I didnt have that problem today. I was able to crawl around for quite a while, and I had a noticeable difference in power steering system power. It was much easier to turn the tires... pretty effortless:thumbsup:

However, I did find that after driving it around for quite a while....and having it at 3-4K rpms or so....front end locked, and steering wheel cranked in 3.5' of snow, the system started to whine some, and heat up.:hehe:
http://img.photobucket.com/albums/v602/drummond/100_1097.jpg
So....to deal with this, I went up to the junkyard and picked up a power steering cooler out of a 97-98 Chevy 1 ton, and I will be installing this in the next couple days, and I will post with a update on how that works
http://img.photobucket.com/albums/v602/drummond/100_1099.jpg

So far I am very impressed. It is much better than before, and should allow the bigger box to get the fluid it needs, to turn the tires much easier on the rocks :woot:

Beefy

01-21-2008, 08:02 PM

:thumbsup: Looks good brent

sglide

01-21-2008, 08:04 PM

excellent write up Brent

Grandman

01-21-2008, 08:19 PM

excellent write up Brent

Yes indeed it is . I am aware of this up grade but i worry about the PS hoses taken the new preasure supplied .

You really think more flow was need or just the increased preasure ?

Iv been thinking about just removing that shim .

drummond

01-21-2008, 08:25 PM

I am pretty sure that it is more flow, as well as more pressure. I read somewhere on Pirate4x4 where Matt from West Texas Offroad was talking about how drilling out the Main fitting increases the most flow at idle and low rpm, because the piston isnt doing as much work to push the fluid when there are not a lot of RPMs, so by drilling out the hole it allows more fluid to be forced through the box. I dont think it does as much for higher rpms. This was noticeable on my Jeep because I had most problems at low RPMs anyway, and now with the increased hole size, I feel that it helps. No whine, and much easier to turn. When you see the size of the stock main fitting hole (small), I think that you may consider opening it up some. I only opened it up .0625", but I feel that made a large difference in performance.

My largest concern right now is the heat that it could possibly generate, due to pushing more fluid, and a larger box. I think that this cooler mounted on the front side of my radiator should solve this problem

Mongo

01-21-2008, 08:34 PM

I thought that you guys got snow up there?

Grandman

01-21-2008, 09:02 PM

.0625",

DO i look like a machinist to you ? what size drill bit did you use :hehe:

Grandman

01-21-2008, 09:03 PM

.0625",

DO i look like a machinist to you ? what size drill bit did you use :hehe:

If i read you post correctly and what i heard before removing the shim only ups the preasure right ?

drummond

01-21-2008, 09:08 PM

If i read you post correctly and what i heard before removing the shim only ups the preasure right ?

Yes the shim ups the pressure. Drilling the hole increases the flow of fluid to the box (volume), which makes it easier to turn at the low RPM's when the piston isnt pushing as much fluid.

My stock hole in the main fitting was 1/8" and I drilled it out to 3/16", so I had a difference of .0625 or 1/16" over the stock hole. I think 3/16" is a pretty good size for that hole, just allows more fluid to flow.

Grandman

01-21-2008, 09:21 PM

HMMMM sounds like if i was to do only one thing id want to drill it out rather then remove the shim . That takes care of my worry of blowing lines as well .

drummond

01-21-2008, 09:27 PM

The thing about the shim is, if you end up having problems with too much pressure, you can always put the shim back in. You arent drilling or modifying anything with that piece. That is suppose to really help with the more pressure to turn the tires on obstacles etc. I did not notice any noticeable difference in line pressure..... and I drove it around for about an hour, feeling the lines. I think when you increase the size of the flow, it helps to increase some of the pressure. So I am not sure if the line pressure would be different if I didnt drill out the main fitting? Might be more due to less area for the fluid to flow when its under pressure? The shim is really small as well, probably only between 1/32" to 1/64" or so thick. The shim removal is the most common, and some people take it farther by putting that washer inside the piston, and clearancing the stud. I wouldnt want to do that. That is when the pressure really increases

The thing that I did notice though was the heat, and that is why I will try this cooler I picked up cheap at the junkyard

Bronco4-Play

01-21-2008, 10:41 PM

Nice article. Keep us posted on the heat issue. I'm looking at adding hydro boost brakes to a steering pump that already has more than it can handle turning my 38's. Heat and enough volume have been my main concern in adding the hydro boost, you just answered the volume question if I can keep it cool.

Tonka

01-21-2008, 10:58 PM

you can use a trans cooler on the low pressure line to help with heat

drummond

01-21-2008, 11:16 PM

you can use a trans cooler on the low pressure line to help with heat

yes i could have done that. However, I will try this first, because this will fit behind my grill in front of my radiator, and the trans cooler i could find would not fit....due to fiberglass body. And....this was cheaper:hehe:

Mongo

01-21-2008, 11:19 PM

Will this work on my yj Brent?

drummond

01-21-2008, 11:40 PM

Will this work on my yj Brent?

It should. The boxes have the same basic design and work the same way:thumbsup: Just the dimensions may be slightly different than mine.......but I am pretty sure the Jeep boxes are really close to the same, especially YJ and CJ

Mongo

01-21-2008, 11:49 PM

Good you can do it next time in town.

drummond

01-21-2008, 11:51 PM

Good you can do it next time in town.

:thumbsup:

drummond

01-24-2008, 07:53 PM

I got my PS Pump cooler mounted in between my Taurus fan and my radiator, and all the lines hooked up tonight. Should have pics, and a testing opinion on how it works tomorrow

Grandman

01-24-2008, 07:59 PM

I was going to do this mod today but i had 2 grand girls all day .

drummond

01-24-2008, 08:11 PM

Here is another site that I found yesterday that pretty much did some of the same things that i had found at other sites, to improve power, is also another good resource http://westtexasoffroad.homestead.com/powersteering.html

jsawduste

01-24-2008, 08:55 PM

Many folks underestimate the amount of heat a PS system generates. The fact that you found a factory cooler in the salvage yard is a testament.

Couple of other things to think about.

Changine the diameter of the pully can have a major effect on the pressure/flow rise.

A PS fluid remote resevior with the extra fluid capacity is a good way to reduce the foaming that causes the whine from overheating. Acts as an expansion tank and also helps in the cooling.

Marv, the hoses have a burst rating quite a bit higher then the pump can put out. The big thing is the detoration from aging and vibration.

drummond

01-24-2008, 09:00 PM

drummond

01-31-2008, 01:22 AM

A PS fluid remote resevior with the extra fluid capacity is a good way to reduce the foaming that causes the whine from overheating. Acts as an expansion tank and also helps in the cooling.
.

Do you know where I could find information, or a picture to make something like this? I have tried searching for a design for this with no luck. I may be willing to give this a try.

Bronco4-Play

02-17-2008, 12:17 AM

Medium duty Ford and Chevy diesel trucks use a remote resevior power steering system. You may find one in a boneyard or behind a barn that you can pick up reasonable. The ones I have are late 80's, F900 and C6500 series. The Chevy holds about a pint and a half, the Ford holds about a quart and a half.

Wildhorses.com and broncograveyard.com have new aftermarket units with a filter in them but they are real pricey.