Power steering pump 2003

[solidaxel]

Is the pressure from a 2003 P/S pump the same as the pressure on a 78 1/2 ton pump?

I had the "expert" drive HER 78 truck and she said the "steering felt very loose"

I only changed the high pressure hose and large pump fitting, was I supposed to change other parts from the old P/S pump?

[BR3W CITY]

Not sure of exact pressure, but adding the modern pumps always seems to make them a little touchy.

Some folks had/have an orifice restrictor that is supposed to help. I've seen a variable one as well, which I had considered. Mine is pretty light, but I have a small steering wheel and like the flick-the-wheel steering.

[68c10airstream]

Hi solidaxle, If my memory is correct when i installed the 2001 5.3 in my 68 i used the 68 fitting in the back of the 2001 pump. I'm currently using a 1985 2wd steering gearbox, variable ratio, 3.5 turns lock to lock. Steering wheel feel has everything to do with the spool valve installed inside the gearbox, not the pump provided it can produce enough pressure. Ps pumps usually produce about 1500-2000 psi max, the spool valve controls the use of this pressure. I stayed away from 1996 and newer gearbox's because they went to an easy steer spool valve and i feel it is too much assist. I haven't spent enough time with the 2000 and newer gearboxes to evaluate them properly. My prior engine was a 1997 vortech 5.7 with the supplied ps pump and found no difference in steering feel. My truck when i bought it 10 years ago was a 307 powerglide with factory ps. First change was to the 1985 gearbox. So after a 307 (68 pump) 1997 5.7 (97 ps pump) and a 2001 5.3 (2001 ps pump) there is no difference in steering feel once i put on the 85 box, considering all of the prior changes. A long story i know but i felt it was worth it. Good luck, Brian Fuller

[68c10airstream]

I must add that my prior post i was talking all gm parts. On a different ps subject i've heard of gm ps pump mods needed when using it coupled up to a mustang II rack and pinion setup, as the gm pump stock is too much for the mustang rack.

[solidaxel]

Thanks Brian,
I have had lots of Mll time on Rack & Pinion so I have changed "many" Saginaw pumps to work with Mll, but my 78 has the same gear box it came with, so is it the same as the 85 you speak of?
Will it help if it had more castor dialed in?

[littlevictories]

heh, just fired my swap for the first time and noticed the super light wheel. but I figured it had something to do with the manual steering/manual trans/manual brakes '76 c-10 i've been driving as a loaner while I do the swap.

[solidaxel]

I read somewhere on here that moving the LS engine to the rear changes the weight bias, BUT I would not think it makes the front end that much lighter or the steering feel that much "lighter" just a question.

[BR3W CITY]

The engine position gets felt in the handling, but not in the touchiness of the steering. The front end feeling light, and the steering feeling light are two different sensations if you put them back-to-back.


Hey 68airstream; I'm running hydroboost, which makes a bit more pressure than the other systems, but running it to my 71 steering box. Do you know if the spool valve can be changed or modified?

[crazy longhorn]

Yup. lay the caster back , on that truck , that you want to see fast Hyway speed...longhorn

[68c10airstream]

Hi br3w city, The spool valve can be changed to effect the effort it takes to move the steering wheel left/right. The spool valve that i like the best was called "firm feel". The steering box i believe has a letter(s) code stamped into a big round disc on the forward most area of the box. Think of the spool valve as a flexing (twisting) shaft. It's a straight shaft that is turned down to a thinner area in the middle, hence it causes the feel to be transmitted to the steering wheel. On one end of the spool is the steering wheel input, on the other end of the spool is the hydraulic ports to be opened up for assist to turn right/left. We have all driven a vehicle that dies on the road, and how hard it is to move the steering wheel without the assist of the engine running. This firm feel in the oldsmobile product line i believe was part of an option called FE3, and on chevy it was F41. I believe Lee's power steering rebuilds a box to the specs you want. I remember a lengthy article on there rebuilds and he talked about all of this, info that you typically don't read about. For trucks i like the variable ratio box from probably 71-72 to 95, 3 1/2 turns lock to lock. This info was stated on the glove box starting on the mid 70's as simply "variable ratio" I will send my box in for rebuild the second it starts to leak, and before i remove it i will be using a pull scale (fish scale) to measure my current steering effort to be able to spec a firmer spool. A good rebuilder should be able to take that info and measure the thin area of my current spool and spec a replacement spool to match my wishes. If they can't do this i would say there are not on top of their game and i would go else were. Borgeson has bought up all the old saginaw steering gear machinery and can now make copies and put together a brand new box. Good luck, Brian Fuller

[solidaxel]

Thanks Brian for the info on Lee's power steering service.

I just talked to them and they informed me that the rack and pinion from the 2003 Silverado has different pressures than the Ricir. ball box on my 78 1/2 ton and he suggested to send in the 2003 pump for a rebuild and pressure change to fit my truck
1 1/2 week turn around and 135 plus shipping!!

Just in case I can not live with the way it feels !!

[68c10airstream]

solidaxel, if you rob parts from the earlier ps pump you had, take the fitting, spool underneath the fitting and the spring. Install this in the newer ps pump. The spool and spring control dead head pressure (max pressure) and flow. I believe speedway motors, etc sell a mustang II modification to the saginaw pump that involves washers and spring, and possible spool. It wasn't very expensive and you can control the outcome.

[solidaxel]

Thinks Brian,
That is what I was looking for a answer!

These vain pumps look the same 2003 and the 78 and the fittings will interchange, so I am going to change the rest of the parts.

I am surprised no one else has made any comments about the steering feel on these old trucks.

[truckdude239]

Mine feels fine with the ls pump but i also used the metal vavle and fitting off an 78 pump

[akdg87]

there's a much cheaper alternative for adjusting pressure, i was looking into it for my rack and pinion with the ls hydro-boost p/s pump, but turns out i didnt need it. i think the kit is less than $30 on summit.

It can be done with simple tools, for less than $135 bucks you could buy a new pump and this kit: http://www.borgeson.com/xcart/catalo...p-1-c-133.html