Can someone with experience please tell me which port is the pressure port(pressure line from pump) on the power control valve? The 2 ports that go to the cylinder(ram) are obvious, and my thought is it’s the smaller of the other 2, but the guy that pulled it apart is saying it’s the larger port that has a check valve down in the port. The way the check is working I can see his theory that it wouldn’t let the oil return to the reservoir but I can feel a gallery off towards the control spool ,which is between the check and the port seat which would allow it to be the return port, that and a few years of hydraulic experience tells me the pressure line is nearly always the smaller line and the return is the largest line. To confuse things he swears(believes)that it’s the way it was plumbed up when he pulled it apart a month ago . Thanks in advance for any input. Chris
Is one of the ports above the other? I've looked in a number of 50's Mercury and Edsel manuals and they show how to rebuild the valve with good pictures, but they do not identify the ports. The closest one I found was in a 58 Edsel manual where it shows the pressure port above the return port. It appears there is a check valve between the ports. It looks like if you hooked it up backwards, the check valve would open and return the pressure feed back to the reservoir.
Last time I hooked one up backwards (and I don’t remember which port was which) it spun the wheel to full lock hard enough to break your wrist then puked all the fluid on the floor. So I’d study the drawing closely. If you don’t get a clear answer here, ask over on the Ford Barn. Someone will post the factory manual pictures most likely.
I’ll check my Power Steering Supplement manual when I get home this evening. I’m about to pull the power steering apart on my ‘55 Mercury to rebuild it. So, pictures of the valve and hoses should be pretty easy to get.
Thanks for the input, rebuilding the valve is not a problem, it’s relatively simple, as is the pump. My problem is, I have every confidence in the fella that rebuilt the pump and valve in the first place, a well regarded transmission builder of 50 years, but he is convinced the hoses are in the correct position from tear down. It’s one of these situations where it worked perfectly besides leaking, once resealed it’s not working. A simple fix I’m thinking, just knowing for definite which port is which is all I’m looking for. I’m 2 hours away from the car and only got a couple of hours with it Tuesday, I’m convinced the port with the check valve down it is the return port.
Here’s the functional diagram (‘53-‘56 Ford/Mercury) of the power steering system. This is the best pic I could get of the control valve on my ‘55 Mercury with the “pressure” and “return” lines indicated. Hope this helps!
Just as feedback to the question, I changed the pressure and return at the pump as they had been put on back to front, The pressure hose has a banjo fitting on the pump end and as the ports are the same size on the pump it had been fit to the return port on the pump via the banjo bolt. The pump end of the return line has a AN female which was fit via a male AN fitting in the pressure port. I was informed they were like this originally but once I realised the ports were the same that they could be back to front. After correcting this, I thought it was sorted, only to start the car, touch the wheel and off it went ,spinning back and fourth. The lines from the valve to the cylinder were as per the above photo, side by side , they were then crossed over and at last , we have power assisted steering.. Next question is why would the lines to the cylinder need to be crossed to work correctly when all others I’ve seen are parallel? The problem is gone but that is still strange! Thanks again for the input.
I’m not a hydraulics expert. The only thing I can come up with is the hydraulic system went into a positive feedback loop. If the input lines are on top of the mounting bolt center line ( instead of below, the input lines effectively reversed), the cylinder would constantly push then pull on the control valve. The cylinder would stroke until the control valve reversed the direction.Then do the same thing all over, again. Back and forth. I’ll try to get a picture of my cylinder to help you confirm your line orientation. Hope this helps!
Okay, I know this info isn't completely related to the unit you are asking about, but just an FYI...the power steering box in a 55-56 has more teeth gears than a standard steering box. I have 2 of the 56's, one came factory with PS. I couldn't find the patience to rebuild the leaky thing, and once I swapped the engine for a SBF, out it came. Now, it steers almost like PS, even though I replaced the steering with a stock unit. If you find a parts car with PS, snag the box for a spare...you never know!
Actually, there is no designation for power steering or non power steering. The ‘54-‘55 Ford/Merc/‘55 Tbird (and early production ‘56 models) used the 2 tooth sector boxes. The ‘56 Ford cars, ‘56 Mercs (to mid year production) and the ‘56-‘57 Tbirds used the 3 tooth sector boxes. The ‘55-‘57 Tbird steering speed was quickened by shortening the steering arms at the spindles. Rebuilding these steering boxes is relatively easy. One of these days, I’ll put together a “how to” thread. I forgot to add (since the original poster is from Australia), the RHD ford cars used the same year break down for 2 tooth sector vs 3 tooth sector boxes with the 3 tooth extending to the ‘57-‘58 models.
RSC, thanks again for your input , We can put this to bed now, your picture above tells the whole story. If yours is correct, which I don’t doubt at all, the cylinder on the car I have been working on has been mounted upside down, hence the need for crossing the lines. The ports are above the mount, not below as pictured. The other day working on it, I noticed how hi it was mounted but there was clearance so didn’t think anything of it. And, just to add, it is a Left hook car, imported a few years ago to OZ. Thanks again for your input. Cheers Chris.
You know what? After all my life around 50's Fords I learned something new about them because of your info...Thanks! That makes sense completely. My 2-door sedan 56 is an early 56 and steers like a weight machine. My other one (which had PS) is a late 56, steers way smoother, and I had been told by an old fart who worked on them about the difference. I appreciate the info, thanks!
any hints on making sure the hose ends are not leaky or what you'd do to seal them good and shut without rounding them??
I use nothing. No leaks in 12 years. They are made not to need sealant unless you’re talking about the fittings to the controller case. If you feel you need something use copper washers only.,
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