I did an LS1 swap in my 76 last summer and used the late model power steering pump. Now I am doing a rack and pinion swap and want to know if the pressure side fitting in the new pump is the same type that is in the 81/82 style pump. When I did the motor swap I just cut the existing line and spliced it together with the line that was on the new pump.
power steering fittings
- Thread starter delbert62
- Start date
68/70Vette
Well-known member
The late model pumps have metric/o-ring fittings for the high pressure outlet. The early models were english compression fit high pressure outlets.
Power steering repair shops sell brass adapters to mate a english threaded fitting to the metric/o-ring outlet, and vice versa. They are cheap about $6.50.
Another method is to remove the pump reservoir, called a ham can since it looks like a Danish ham can. You can remove the metric.o-ring fitting and replace it with an english threaded fitting. That's what I did, since at the time, I didn't know about the simple adapters.
Power steering repair shops sell brass adapters to mate a english threaded fitting to the metric/o-ring outlet, and vice versa. They are cheap about $6.50.
Another method is to remove the pump reservoir, called a ham can since it looks like a Danish ham can. You can remove the metric.o-ring fitting and replace it with an english threaded fitting. That's what I did, since at the time, I didn't know about the simple adapters.
mrvette
Phantom of the Opera
Since doing my rack swap previous to any commercial offerings by about a year or better, I have to say from all the feedback I have read, apparently I lucked out, and keeping my '72 vette stock brass fitting/valve in the back of the pump was a good idea, the pump was upgraded to a serp drive some 15 years ago, years later the rack conversion was done, keeping the '72 pump valving with the flare fitting...
now here is the cute part....according to JimL82, Jim Shea, the racks are set for some 1500 lbs line pressure and the old vettes were set at 900 lbs pressure, so using the lesser pressure valving has put less assist on my rack...and it feels GREAT, I don't feel i'ts over assisted like many other guys do about their conversions....
I used a simple 3/8 plumbing compression union to join the lines I cut and spliced, did the same for the hydroboost conversion years later....
:smash:
now here is the cute part....according to JimL82, Jim Shea, the racks are set for some 1500 lbs line pressure and the old vettes were set at 900 lbs pressure, so using the lesser pressure valving has put less assist on my rack...and it feels GREAT, I don't feel i'ts over assisted like many other guys do about their conversions....
I used a simple 3/8 plumbing compression union to join the lines I cut and spliced, did the same for the hydroboost conversion years later....
:smash:
Thanks for the replies guys. This gives me a couple of options. The reason I asked if they were the same as the 82 is that VBP sells a hose correct for the 80-82. I wondered if it would be a direct fit.
68/70Vette thanks for answering my post on CF also
68/70Vette thanks for answering my post on CF also
Gene,
I will tell you why your rack & pinion feels so good. Your 1972 pump puts out only 1.6 gallons per minute of flow. 1970 thru 1973 pumps all had that same 1.6 gpm output. 1963 thru 1969 pumps had 1.75 gallons of flow. 1974 thru 1981 pumps put out 2.9 gallons per minute. The 1982 pump put out 1.9 gpm.
That low flow makes your R&P valving very slow in response. Translating to a heavier on center feel.
It's not the pressure relief!
Jim
I will tell you why your rack & pinion feels so good. Your 1972 pump puts out only 1.6 gallons per minute of flow. 1970 thru 1973 pumps all had that same 1.6 gpm output. 1963 thru 1969 pumps had 1.75 gallons of flow. 1974 thru 1981 pumps put out 2.9 gallons per minute. The 1982 pump put out 1.9 gpm.
That low flow makes your R&P valving very slow in response. Translating to a heavier on center feel.
It's not the pressure relief!
Jim
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mrvette
Phantom of the Opera
Since I am running a '87-88 vette serp pump with remote reservoir, and that '72 valving, I have to assume that valving limits the flow also, along with the pressure....so I better make sure I retain that '72 valving if I ever change pumps??
Am I to assume that the pumps are in fact nearly identical inside and that it's all in the valving as to pressure AND flow....
IF so, that's interesting, on center down the freeway, I see no demand on the pump, wouldn't pressure rise? the available flow is not used...
obviously I don't understand this too good....:surrender:
and I just lucked out, apparently...
:thumbs:The rotary valve in the power gear is open center. So when you are driving straight down the road, there is no demand, and full flow right through the valve back to the pump reservoir.
When you begin to steer you actually twist the torsion bar in the rotary valve, the movement of one part of the rotary valve partially closes off some ports and starts to restrict flow, pressure builds, and a port is opened for that pressure to react against the side of the piston in the gear that requires assist.
It didn't dawn on me that those four years of Corvette production had the lowest flow of any C2/C3 until you asked your question and I looked it up. That definately would affect how your steering feels. That might also explain why some people are not real happy with the steering feel of their Steeroids systems (they are most likely using pumps with much higher flows). I would also bet that remanufactured pumps do not even consider exactly what years and what discharge fittings were used for exact C2/C3 years.
Gene, you might try this. Take your car to a large vacant parking lot. Drive along at about 25-30 miles per hour. Then suddenly whip your steering wheel to make an evasive maneuver as if something suddenly darted out in front of your Vette. I would be interested in your have full assist during that maneuver or if you suddenly feel a real sharp increase in effort because your pump is putting out so little flow. That also might explain why later model Vettes were changed to 2.9 gpm pumps.
Saginaw was very good at designing and producing steering components that had a lot of interchangeable parts between years and models. That is why you could use the discharge fitting from your original P-pump in the pump with your serpentine system. The maximum amount of pump flow is essentially dictated by the throat size in the discharge fitting.
Jim
When you begin to steer you actually twist the torsion bar in the rotary valve, the movement of one part of the rotary valve partially closes off some ports and starts to restrict flow, pressure builds, and a port is opened for that pressure to react against the side of the piston in the gear that requires assist.
It didn't dawn on me that those four years of Corvette production had the lowest flow of any C2/C3 until you asked your question and I looked it up. That definately would affect how your steering feels. That might also explain why some people are not real happy with the steering feel of their Steeroids systems (they are most likely using pumps with much higher flows). I would also bet that remanufactured pumps do not even consider exactly what years and what discharge fittings were used for exact C2/C3 years.
Gene, you might try this. Take your car to a large vacant parking lot. Drive along at about 25-30 miles per hour. Then suddenly whip your steering wheel to make an evasive maneuver as if something suddenly darted out in front of your Vette. I would be interested in your have full assist during that maneuver or if you suddenly feel a real sharp increase in effort because your pump is putting out so little flow. That also might explain why later model Vettes were changed to 2.9 gpm pumps.
Saginaw was very good at designing and producing steering components that had a lot of interchangeable parts between years and models. That is why you could use the discharge fitting from your original P-pump in the pump with your serpentine system. The maximum amount of pump flow is essentially dictated by the throat size in the discharge fitting.
Jim
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