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Power steering power issues

Slick67

Jr. Member
Joined
Mar 15, 2024
Messages
82
So-
Ever since the trans was swapped from c4 to zf5, the power assist goes away fully, to the steering- as soon as you hit idle.

Obviously, this is a PITA, being that you push the clutch and the motor idles…. and no steering.

As soon as you get 1 rpm you have full power back to the wheel. It’s on its 3rd or 4th pump swap to rule out a ban reman on the 1st 2 and a lemon on the 1st new 1 …

MY THEORY FOR A FIX- would be to mill a smaller pulley for the pump so, at idle, it spins, just a smidge faster.
🤷‍♂️
Ideas, thoughts

FYI- it’s just your run of the mill 67 with 351 and 34-12.5, 15’s
 

1969

Contributor
Sr. Member
Joined
Feb 28, 2022
Messages
532
What power steering pump are you running?
 

SteveL

Huge chevy guy
Joined
Jun 24, 2001
Messages
11,656
Loc.
Hawthorne ca
I'm assuming you already have a Saginaw pump. The options I came up with are
1) there is a smaller diameter pulley(I think early corvette) you can machine to fit the press on shaft.
2) another option is swapping the pump to a keyed pulley shaft and march offers a Purdy aluminum one.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,937
Post a pic of you pulley setup. Just want to make sure someone didn't do an underdrive crank pulley or something else odd.

What do you idle at?
 
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Slick67

Jr. Member
Joined
Mar 15, 2024
Messages
82
Saginaw pump

Idle is where it should be

And rig is in storage atm so can’t take a pic
 
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Slick67

Jr. Member
Joined
Mar 15, 2024
Messages
82
What does that mean?
What is your idle speed exactly?
And can you tell whether or not it drops below idle for a moment, when you let off the gas?

Can’t answer exactly.

It idles fine, slower and it would blip and stall. Faster and it would be more at a rev.

It is in storage so it’s nothing I can give an exact numeric value to.

When the clutch is pressed and you let off the gas, it goes to normal idle. *barring some abnormal event.

I’m baffled by it not occurring with the c4. And also that the slightest rev gets the power back.

Of all posts- I think the corvette pulley mod sounds like the most promising mod.


Sent from my iPhone using Tapatalk
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,639
Thanks. Don’t remember what you have, even though I’m sure we’ve spoken about it before. But are you running a carburetor or fuel injection?
And did you change anything on it when you got rid of the automatic transmission? Obviously it had a kickdown lever, or should have. Did you remove that completely?
 
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Slick67

Jr. Member
Joined
Mar 15, 2024
Messages
82
Carb, yes.

I didn’t pull the c4 myself…. So I’m not sure what was changed aside from the transmissions, and such. And without looking, I’m not sure about the kick down.


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