The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 55.2-59 CPP 400 Power Steering kit... how long are the hoses?

1project2many · 08-30-2021, 10:07 PM

daveshilling, you may find the old pump does not produce the correct range of pressure towork with newer steering gear. The '50s systems were (IIRC) typically about 800-850 psi while newer systems frange to around 1600 psi. I had to learn this lesson the hard way when trying to use a newer pump with the super rare GMC box.

Many years later, I know the super rare GMC system is not as rare in the GM world as in the GM truck world. Buick, Olds, and Pontiac used similar pumps and boxes and there are folks who supply repair parts and who will do it for you. Classic Industries does sell parts for resealing the system: https://www.classicindustries.com/pr...s/5683483.html

A diligent person could use the GM Parts wiki to locate OE seal numbers to cross check applications although I suspect there are folks on HAMB, Tri-Five, and on AACA who will be able to talk about rebuilding these systems from experience. I know that when I had this system in the '80s parts were available over the counter in many parts stores.

I wish I had time to provide more than hints and suggestions but I believe that you may, if desired, be able to rebuild the original GMC system.

08-30-2021, 10:07 PM	#10
1project2many Registered User Join Date: Mar 2012 Location: Lakes Region NH Posts: 3,158	Re: CPP 400 Power Steering kit... how long are the hoses? daveshilling, you may find the old pump does not produce the correct range of pressure towork with newer steering gear. The '50s systems were (IIRC) typically about 800-850 psi while newer systems frange to around 1600 psi. I had to learn this lesson the hard way when trying to use a newer pump with the super rare GMC box. Many years later, I know the super rare GMC system is not as rare in the GM world as in the GM truck world. Buick, Olds, and Pontiac used similar pumps and boxes and there are folks who supply repair parts and who will do it for you. Classic Industries does sell parts for resealing the system: https://www.classicindustries.com/pr...s/5683483.html A diligent person could use the GM Parts wiki to locate OE seal numbers to cross check applications although I suspect there are folks on HAMB, Tri-Five, and on AACA who will be able to talk about rebuilding these systems from experience. I know that when I had this system in the '80s parts were available over the counter in many parts stores. I wish I had time to provide more than hints and suggestions but I believe that you may, if desired, be able to rebuild the original GMC system.