What is sensor on side of PS pump?

Thomas95SC

Registered User
What is the sensor on the side of the PS pump that the high pressure line goes to? Is it the variable assist? I have a small leak coming from it. Maybe bad o-ring? I noticed when I installed it on the new PS pump, the middle section didn't want to swivel when i tightened it to the pump. Is this normal? Trying to figure out if the sensor maybe has an internal leak or the o-ring is bad on the end fitting.
 
Unscrewed it from from the old one. It has a hex fitting in front of the part that the high pressure line screws in.
 
That's the EVO valve. (Electronic Variable Orifice), which gives you the variable assist power steering. You are experiencing the same leak that I had. There are two o-rings underneath that sleeve, so you have to take it apart. (it pulls apart, but it sometimes is not that easy to do) See my pictures and explanation at this link

http://www.sccoa.com/forums/showthread.php?p=814257#post814257

You will have to get the o-rings in a power steering pump seal kit. Each kit only has one of the o-rings you need, so you have to buy 2 kits. (Part #8526). Each kit should be less than $10. I bought them at Autozone the last time I needed one. (I just looked at AZ website, and they now say you have to special order at the store or order online.) You might be able to find them elsewhere locally, or just order on internet like I do. Also, when you put the high pressure connection (at the EVO) back together, don't forget about replacing the teflon seal. You can get those at Ford (Part #388898-S).

Until you get the o-rings replaced, I've found that Lucas Power Steering Stop Leak does a good job at slowing the leak.
 
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Ford will sell you the O-rings, there are two different sizes. I bought a pack of each but unfortunately I lost one of the packs and don't know where the other is right now. If memory serves a pack of O-rings from Ford is cheaper than $10.
 
Yeah, it was the inner orings. I ordered an oring kit and matched them up as close as possible. So far no leaks. I asked Ford but they said they don't carry just the orings and that I would have to buy the whole sensor for $323!
 
I hate lazy arse guys, making me go out and hunt those o-rings. PNs 387571-S and 391032 S (interchange for PN# 389349S).

Found my receipt. They list at $1.27 and $1.39 each and come in packs of 4.

All EVOs on CII pumps use these seals so if they balk at it being a SC just tell them its a Windstar or a Mustang.
 
I hate lazy arse guys, making me go out and hunt those o-rings. PNs 387571-S and 391032 S (interchange for PN# 389349S).

Found my receipt. They list at $1.27 and $1.39 each and come in packs of 4.

All EVOs on CII pumps use these seals so if they balk at it being a SC just tell them its a Windstar or a Mustang.


Thanks for posting those part #s. I agree....I hate lazy parts guys...problem is...I have never been able to find a parts guy working at a local dealership that acts like they really want to help.......They usually act like I'm bothering them...even though I'm the only one standing at the counter.....That's why I usually order on the net. Cheaper price and better service.

Just ordered some of these o-rings. Looks like the 387571S is the o-rings under the sleeve. The other part # is much smaller, and I haven't determined whether it's for the end of the EVO or what?
 
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