Ford 4000 plessey PS Pump

wink4000

Member
I am rebuilding my Plessey power steering pump -- closest part number I could find is C7NN-3A674-F though the true part number is C5NN-3N675-F. I have a couple questions-- I have some seemingly minor scoring on the inside of the pump where the two gears meet, everything seems tight and doesn't have much play, but I have read this scoring can be detrimental, is this true?

Also, there are three hose receptacles on this pump, one is labeled "in" one is labeled "T" and one has no label. Does anyone know what the "T" means?

Basically, I had to replace my reservoir - old reservoir had three nipples to accommodate two returns and one to the pump. But the new reservoir only has two.. In and an out.. Can I block the T or the no label and still have power steering with this pump?
 
T is usually for Tank. This port is where oil that passes thru the relief valve gets back to the reservoir. Not a good idea to plug this port. The unmarked port is probably for pressure to the steering valve. Not a good idea to plug this either. Scoring of the center plate means your pump is junk. Replace it.
 
The original 4000 PS systems had 3 lines on the tank: 1) inlet to pump, 2) return from steering valve, and 3) return oil from pump flow control & relief valve. If you are forced to use a 2-nipple tank, I'd join lines 2 & 3 if you have no other option, as they are both returns anyway, and it should accomplish the same result. Do not block the "T" line on the pump - that would be bad. Also, make sure that your pump inlet is drawing from the bottom of the tank.

Minor scoring inside of a PS pump is quite normal. If the steering still works OK, and everything else in the pump is tight, I would continue to use it, since that style of pump is superior IMHO to the later ones with the integral reservoir that Ford transitioned to.
 
(quoted from post at 20:58:14 05/30/17) The original 4000 PS systems had 3 lines on the tank: 1) inlet to pump, 2) return from steering valve, and 3) return oil from pump flow control & relief valve. If you are forced to use a 2-nipple tank, I'd join lines 2 & 3 if you have no other option, as they are both returns anyway, and it should accomplish the same result. Do not block the "T" line on the pump - that would be bad. Also, make sure that your pump inlet is drawing from the bottom of the tank.

Minor scoring inside of a PS pump is quite normal. If the steering still works OK, and everything else in the pump is tight, I would continue to use it, since that style of pump is superior IMHO to the later ones with the integral reservoir that Ford transitioned to.


Thanks guys, very helpful. Looks like I need to get a new pump, Should I search for a pump with all three lines (inlet to pump, and two returns)? I have also seen pumps with just the two lines(one in one out), is this a modern adaptation or a pump that won't suit my needs?
 
If you go looking for a new pump and see the
prices on them you'll quickly figure out why
many of them get converted to the new style
with integral reservoir. Prices are like
$400+ for the old style vs $175 for the new
style. If the new style doesn't last as long
you can still by 2 of them for the price of
one old one. They are much easier to add oil
to also.
 
(quoted from post at 04:50:12 06/01/17) If you go looking for a new pump and see the
prices on them you'll quickly figure out why
many of them get converted to the new style
with integral reservoir. Prices are like
$400+ for the old style vs $175 for the new
style. If the new style doesn't last as long
you can still by 2 of them for the price of
one old one. They are much easier to add oil
to also.

So this new style will fit on the old mount? The ones I have seen don't mention the C7NN3A674F (or the C5NN3N675F) replacement part number... Appreciate the help folks!
 

Ultradog,
I have a post about my PS reservoir leaking out the top. As I read your reply
[b:916bb219ea]" Prices are like $400+ for the old style vs $175 for the new
style."[/b:916bb219ea]
Would that work with my 4000 ?
??
Thanks
 

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