My power steering only provides assist in one direction from center. Is this likely to be the control valve? I thought there was a troubleshooting thread here on the forum, but I can't find it now.

 

Its WAY out of adjustment.

 

Doesn't that pull the wheel in one direction or the other? Not arguing, just asking. My wheel is centered going down the road.

 

https://www.google.com/url?sa=t&rct=...10151844,d.eWE

I would go to Jim Shea website and read his paper on control valves.

 

Thanks, lots of good info there, but I didn't see anything that specifically describes control valve symptoms. Did I miss it?

There's a video on the site that shows how to install and adjust a control valve that's been rebguilt by Lonestar. When I went to the Lonestar site, the home page says "Wholesale Only." Not sure I understand... what's the point of advertising in a video this way if they don't sell to individuals?

 

Jack it up so the front wheels are off the ground. Start the engine and see if it pulls one way. If it does its likely the valve needs adjusting. If it doesn't pull and it is still hard to turn in one direction, it is probably the cylinder bad.

 

Many thanks for everyone's input. I've decided to rebuild the control valve as a first step to diagnosing the problem. I bought the parts below from NAPA today so I'll have them ready this weekend. If the valve isn't rebuildable for some reason when I pull it off the car, I'll return the parts and buy a rebuilt valve instead. I also picked up the tool to remove the valve, and I found a step-by-step PDF for the work. Incidentally, the bags of rebuild parts from NAPA say all items are made in USA. I'm hoping the work goes smoothly...

Link to PDF instructions:

http://www.cssbinc.com/images/ads/howto/PSV-rebuild%20instructions.pdf

Someone else's photo of the tool being used:



Rebuild parts:





Not sure how necessary it is, but I also bought this filter for the return line:

 

In all my years at Saginaw Steering Gear Division, I never saw an instance where a power steering return line filter really did any good.

I might add that built into all GM power steering systems, there is a powerful, small, disc shaped, magnet that is inside pump reservoir. This magnet is located in the area of fluid flow and picks up very small, metalic wear particles that are created over the life of the power steering system. We would see build ups of very fine, silt like material that would accumulate on the magnet over many thousands of test miles.

I would also be concerned that the filter that is pictured may not have a "blow off" relief valve inside the filter. If the filter were to become "clogged" and restrict fluid flow, the build up in pressure could cause the low pressure return line hose or the low pressure clamps to fail and spray power steering fluid all over the engine compartment.

Jim

 

I recently rebuilt my steering control valve. I followed along with the Willcox video and everything went fine. While it was apart, I also replaced the seal on the steering cylinder and all of the power steering hoses.

I also have the ball joint separator tool in the first photo. I like to reinstall the castle but upside down when using this tool to avoid damage to the threads.

Good luck with your project.

 

Thanks for the info. The filter was an afterthought based on the online recommendations of several parts vendors. It wasn't cheap as filters go, but it has a relief valve and a serviceable magnetic element. I just wanted a little extra protection for the new parts I'm installing. Depending on how the work goes and what I find, it's possible I'll end up replacing or rebuilding everything in the system.

 

Would you post the part numbers for the kits I looked for them and couldn't find them at Napa,AZ,or O'Rielly's. Thanks

 

NAPA part nos:

PS Control Valve Seal Kit: NPS 7137

PS Control Valve Ball Stud Mounting Kit: NPS 7215

PS Filter, add-on type (for 3/8 hose): NSP 810589F

 

Does anyone know the fluid capacity of the power steering system? I can't find it in either the owner's manual or the shop manual. Is two quarts enough to fill a dry system?

 

According to the AIM, .136 Gal. Pg. 344

 

454Luvr, As I sell Borgeson power steering systems Down Under, this question has often been raised. The standard system has a pump, four hoses, a control valve and a power ram to fill and according to page #353 of my 1974 AIM, it says "FLUID -Approx .160 gals. per job." But what is a "job?" Is it a dry fill or a top up? Bearing in mind that if you drain the pump, there will still be residual fluid in the hoses, ram and control valve, so the system, although drained, is not dry.

On page 55 of my 1974 Chevrolet Corvette Owner's Manual, it says "Add GM Power Steering Fluid (DEXRON-11 or DEXRON Automatic Transmission Fluid) as necessary to bring level into proper range on filler cap indicator depending upon fluid temperature."

Nowhere in my AIM, Owner's Manual or Haynes WSM does it tell me how much fluid to add to a dry system. Now as one US gallon = 3.78 litres, then 0.160 gals. = 0.605 litres, or 605 ml., which seems a little light on. Now, a Borgeson box has the ram and control valve integrally and only requires two hoses between the box and the pump, so that 0.160 gals. amount cannot be used. I usually sell my customers two 32 fl. oz. (one quart or 946 ml) bottles of AC Delco Power Steering Fluid and tell them not to use ATF or the warranty will be void. No-one has ever called me back and said that they did not need the second bottle, which implies that more than one quart or 946 ml is required for a dry system.

However, to get back to the original question, it sounds like 0.160 gals. (how do you measure that???) or 0.6 litres (a lot easier to measure) is about right. But not according to Cavu2u whose AIM says 0.136 gals. Again, how do you measure that?

I think that an answer from Jim Shea would shed a lot more light on the subject. Over to you, Sir.

Regards from Down Under.

aussiejohn

 

Just on more reply.
I agree with AussiJohn. My quantity quote came from my '73 AIM, and when I replaced my low pressure hose the other day, I had to add hardly any fluid to the system. I mean like 4-6 oz. Actually had to suck some out of the overfilled pump.

Steve

 

I only can check the 1975 and 1976 AIM books. They indicate 0.16 gallons of 9985010 fluid per job. The pump, assist cylinder, and hoses were shipped to St. Louis dry. So the assembly plant had to pull a vacuum on the entire assembled power steering system and then inject .16 gallons (20.5 fluid oz) into the pump reservoir to completely fill the Corvette steering system.

I am going to inquire (over at the NCRS website) to see if they can tell us if the 9985010 is the correct spec for GM power steering fluid. (Previous to the 1970 model year, GM did specify ATF as an acceptable power steering fluid.)

Point of interest: From 1965 forward, all other GM power steering systems had (what was called) the integral power steering gear with input shaft valve and rack piston inside the gear (not the Corvette system with a manual steering gear, and separate valve, assist cylinder and hoses). The integral power gear was shipped to all other GM passenger car and light truck assembly plants with the gear filled with power steering fluid. The power steering pump, and hoses were shipped dry. Since the power gear was the furthest component in the system, even the assembly plant vacuum fill systems were not capable of drawing 100% of the air out of the system before the fill sequence.
Jim

 

The AIM number is correct. I disconnected all four hoses at the control valve and left them hanging below the level of the power cylinder. That should have mostly drained the system. The refill was a little more than 1/2 quart (0.125 gallon).

 

Thanks Jim, for your once more excellent feedback to our questions. I have often been told by people Down Under that ATF is the same as Power Steering Fluid and "that they have always used it with no problems." And it is true that with the pre-1965 Chevs and all pre-C4 Corvettes, ATF is approved by GM for use in power (assisted) steering systems.

The main difference between an "add-on" power assist system and an integral system is that with the former, it is just a hydraulic pump and ram set-up where the fluid is just doing mechanical work via the ram but none of the fluid goes into the steering box. An integral system has the fluid going into and through the steering box and is no longer being used just for performing hydraulic movements, it must also lubricate the bearings and seals within the steering box.

Because of this, there are different additives in the PSF, compared to ATF. Additives that help prolong the life of those bearings and seals and, therefore, the steering box itself. These additives are not necessarily present in ATF and that is why I tell my customers to only use PSF or their warranty will be void.

As an aside, in Australia, the company General Motors Holden has been around for the best part of a century and Chevs as well as other GM passenger cars and trucks have been assembled from CKD components since the early 20th century until quite recently. Australia's "own car" the Holden has been made since 1948 and in some factories, was built alongside the bigger Chevrolets from CKD components that mainly came from Canada, a fellow Commonwealth country.

All of these cars were, of course, right hand drive and when the 1965 RHD Chevs were being built in Australia, they all had a specially designed RHD Saginaw 800 Series integral power steering box fitted. Pre-1965 cars all had manual steering. I still have a good source for these RHD boxes and have developed a kit that will allow them to be fitted to 1958-64 RHD Chevs that are still running around in this part of the world.

In fact, last weekend, I received an email from a gentleman in India who owned a Canadian built RHD 1962 Chevrolet who wanted an integral power steering box for his car and he found me via my website. I am in the process of boxing up the steering box and spacer kit, along with an intermediate shaft, pitman arm and rag joint made by Borgeson that will complete the conversion.

So, even RHD full size 1965 model Chevrolets had integral power steering boxes, yet GM allowed their "flagship" car to retain the obsolete ram system right up until 1982. Strange world, isn't it?

Regards from Down Under.

aussiejohn

 

Here is a paper that I authored on the evolution of GM power steering fluid. When Saginaw Steering Gear was a division of General Motors and was steering responsible, they had a lot of clout (along with Oldsmobile Division) and kept things in good order with respect to fluids, specs, etc. Here is the paper:
Jim
GM POWER STEERING FLUID

Originally in the 1950’s, automatic transmission fluid (ATF) was specified for use in both General Motors automatic transmissions and also for their power steering systems. But as vehicles got heavier, engines bigger, and temperatures hotter, the requirements for the two different systems changed. The GM Research Labs had a Lubricants Section that began testing and modifying the ATF formulation to improve the performance of the GM Hydramatic, Dynaflow, and Powerglide transmissions. They did this without much regard to the fact that the power steering system was using the ATF fluid as well. Sort of the tail being wagged by the dog.

So around the same time, Saginaw Steering Gear Division and Texaco began testing and developing a fluid specifically for power steering. The fluid characteristics were specifically formulated to provide anti-corrosion and non-foaming qualities with excellent lubrication for year around use. There was also particular emphasis placed on wear testing performance with respect to the vanes, rotor, cam ring, and the driveshaft bushing in the big Saginaw “P” model power steering pump. By the way, the “P” model was the only power steering pump used in all C2/C3 Corvettes and all GM passenger cars and light trucks with power steering in the 1960s and 1970s.

That is why some of the early power steering reservoir caps had ATF specified as the proper fluid to use. All the later pump caps and the owner's manuals have said to use "Approved Fluid". The GM power steering fluid is approved for use in any vehicle with a Saginaw power steering pump.

To be honest, all of the Saginaw power steering pumps adapt fairly well to all kinds of fluids. The pumps are marketed and sold all over the world and are used by many vehicle manufacturers who specify their own power steering fluids. Chrysler in the past has used a very simple mineral based fluid. They eventually changed to GM power steering fluid. I am not sure if they still use GM fluid today or not. Ford uses a special Ford ATF fluid. VW uses a European brand of fluid called Pentosin. All of these fluids reportedly work well in their vehicles.

I have no idea who formulated the PS fluid that is sold at K-mart, Pep Boys, NAPA, etc. This isn’t to say that it is bad. However, the amber colored GM fluid is the only fluid that has been certified and tested in GM durability test vehicles for millions of miles. It also is the only fluid that have been durability tested in the Saginaw Steering Gear engineering labs for hundreds of thousands of hours. All of the rubber compounds that are used in the seals, hoses, etc in the production GM power steering system are tested in the materials laboratory for compatibility with the fluid.

The GM part number for a quart of power steering fluid is 89020661. The previous GM part number for power steering fluid was 1050017. Both fluids work equally well.

BTW, there is a recent push to use Dex 6 automatic transmission fluid as a “universal” fluid for power steering systems was well as automatic transmissions. Nexteer (formerly Saginaw Steering) engineers report that the Dex 6 fluid does NOT perform as well as genuine GM power steering fluid.