Got a basic question. What are the most common power steering problems that would cause hard steering. I have a 78. When the car is stationary and idling or when I'm manuvering the car in and out of the garage, steering is quite hard. I must use two hands in these circumstances. When driving at normal speeds the steering still feels slow and NOT agile.

Thanks!

 

Low tire pressure, wrong caster angle in alignment, low power steering fluid level, bad steering control valve or pump.

 

Keep in mind it's power assisted steering, not full power.

 

That's the way they are if you have the wide tires and the small steering wheel that came out in 78, its power assist at best

The good news is there is a nice post on here, detailing how to bump up the pressure in the PS pump with a Chevy astro van regulator.

I'm waiting until something goes or starts leaking and I'll be doing the upgrade myself. Until then, keep the tire pressure up

 

Had a proper four wheel alignment done at a place that knows C3 corvettes. The alignment is spot on.

I changed the control valve a few years ago but it did not really help.

I may try to change the pump next.

I do have the P255 60 15 tires on this Silver Ann model. And yes, steering this beast has always been a challenge. I heard the more narrow tires are easier to steer.

 

Is there a link to this upgrade you mentioned?

Thanks!

 

You can increase or decrease the output pressure of the p/s pump. You have to disassemble the flow valve and add shims (washers) for less pressure, and remove them to increase pressure.

http://borgeson.com/instructions/899001

You will have to make or buy the tool to hold the flow valve in a vice to disassemble the valve. I think the tool and shims from Borgeson was ~$17. My goal was to reduce pressure as I wanted more resistance, but you can go the other way.


Pete

 

Increasing or decreasing the pump control valve ultimate pressure relief will not change the "down the road" feel of your steering system.

When you driving straight down the road your pump only has to develop 50 to 100 psi of pressure to assist your steering. However, when you are standing still; with engine running; foot brake applied; on a concrete parking surface your pump will have to develop 900 psi or more of assist pressure so that you can turn the steering wheel all the way to full lock.

The control valve (attached between the relay rod and the pitman arm on the steering gear) and the amount of flow from the pump is what dictates the amount of steering assist. Higher flow output from the pump will make the steering more responsive and will result in lower effort to steer the car. The pump outlet fitting can be swapped or the throat of the fitting can be carefully enlarged to increase the amount of flow from the pump. The flow control valve (inside the pump, just behind the fitting) does not have to be adjusted or changed.

Jim

 

What cold tire pressure are you running?

 

Whatever the recommendation is..... 32, 34, etc.... Can't remember off hand.

 

Jim I assume you are referring to drilling out (slightly) part number 24 listed on the diagram above in order to create more flow from the pump. How much larger should it be?

I want my steering to be easy. I want to steer it with a finger!

 

Borgeson!

Pete

 

Just rebuilt the steering on my '80 with 255/60R-15 Goodrich T/A's. New pump from Advance Auto, complete front end kit from a supporting vendor, new hydraulic ram, control valve, and hoses from a local Corvette supplier (looks like Corvette Central packaging). Adjusted the steering box a little and it drives like a dream. Easy steering on the road and turning lock to lock sitting still in my garage is a snap. Some effort but nothing my wife would complain about. You have something else going on.

 

I'm going to just start by replacing the pump with one from Advance Auto. I live in that place.

All of the ball joints, tie rods, control arm bushings, etc.... are original to 1978 and have never been apart. Only thing that has been done to the front end is a complete brake job, shocks, new control valve, hydraulic ram, and hydraulic hoses.

 

PeteZ06,, Is right on the money, I rebuilt one part at a time. six mos. lost. Spent 650.00 & 7 hrs labor & with new Alignment. It is the fun car it needs to be. Have a great one. Gene

 

Part 6 in Jim's diagram can be installed back to front, as I found when I rebuilt my p/s pump. Then it won't work at all.

 

check out the thread link below.
remember if you do drill the fitting the steering effort will be decreased across the full operating range. you may not like how light the steering feels at highway speeds.

http://forums.corvetteforum.com/c3-t...some-help.html

 

Your power steering system may not be providing any "assist" at all. Manual steering is not really that difficult, except for tight turns and/or steering at very slow speeds. Being so difficult to turn the wheel when at slow speeds, it's hard to tell that it might not be working properly at cruising speeds!

The likely problem areas (in order of likelihood sequence) are:

1) low on power steering fluid; if it doesn't have fluid, it can't 'pump'.

2) drive belt slipping, but so loose it doesn't squeal.

3) internal problem with the P/S control valve; it's an easy rebuild for not much money. DIY is less expensive AND BETTER than replacement.

4) P/S pump problem; ie. stuck pressure valve or vane wear-out.