View Full Version : Brake sensor identification

04-17-2006, 10:49 PM
I've got a sensor that's leaking on my 1990. It's located on a hydraulic block mounted on the frame near the rear of the engine with one line coming in and one line heading to the rear. The sensor is screwed into this block with a two wire plug on it.

Is this the infamous pressure sensor? If not, what would I call it when calling into ford?


Mike Puckett
04-17-2006, 11:24 PM
10-4 that's it. Remove it, break the electrical end off of it, fill it with epoxy or JB weld, and put it back on. If you buy a used one it probably won't work.

04-21-2006, 09:36 AM
Found the number. A E9SZ-2B091D if prior build prior to 1-90, and FOSZ-2B091A if build after 1-90. (No longer available from ford)

Now the question, other than doing the above and just taking it out of the loop, has anyone investigated what this thing does. It looks like just a simple hydraulic switch. The question is, is it really just a switch, or is it some plulse wave division dohicky? If it's just a switch, any idea what pressure it's set at?

I may take it to a hydraulic shop and have them test it and track me down a replacement. Only issue is that it may be set to a pressure that's kinda low for most hydraulic equipment.

Anyone try this before?

04-21-2006, 10:20 AM
So that is also a pressure sensor, this is the object that sits on the frame just below the ABS unit? What about the pressure sensor on the ABS unit itself, so there are two pressure sensors?


04-21-2006, 10:36 AM
Isn't that the sensor for the ARC?

04-21-2006, 10:42 AM
Isn't that the sensor for the ARC?

You could be right but there are hydraulic lines going into it.

Mike Puckett
04-21-2006, 03:22 PM
Yes, that switch is for the ARC. It activates the hard ride when the brakes are applied real hard. You don't really need it. It's a funny thread, fine pitch metric, and I looked for but could not find a bolt to install in place of it. I have some used ones but none of them work. I bought one from Bill Evanoff and it didn't work either but at least it didn't leak. I can't believe that no one has ever made a replacement. Try searching junk yards, you may be able to find one that way.

04-21-2006, 04:10 PM
So that is also a pressure sensor, this is the object that sits on the frame just below the ABS unit? What about the pressure sensor on the ABS unit itself, so there are two pressure sensors?


Yes, the pressure sensor for the ABS system and it's pump is on the master cylinder itself.

This one is called Brake Pressure Control Valve and it's tied to the power steering et al parts related to the automatic suspension system.

04-21-2006, 04:39 PM
Good to know, thanks

fast Ed
04-21-2006, 05:28 PM
Mike, those 2B091 numbers are for the complete proportioning block. If you only need the pressure switch, it's still available under p/n F0SZ 3N824 A. It's an oddball base part number for a brake part (normally 3N824 is a P/S pressure switch), but that is the correct one specifically for SC brakes.

Ed N.

04-22-2006, 12:19 AM
Hes correct I just purchased this sensor, like a week ago, all brand new.

The part number I have for it is,


Got it on fastpartsnetwork.com

04-22-2006, 11:10 AM
Thanks for the info. no one locally has one and the cost is just over $100 from them.

I'll track down one of the Ford guys working with us folks.

04-24-2006, 12:47 PM
Got mine for $76.00 on that site

04-24-2006, 01:43 PM
just a bit of FYI... I read somewhere (can't remember exactly where now) that the ARC switches to FIRM RIDE when braking pressure is 400 psi or greater. Don't know if that will help ya Mike, but if ya go in search of an alernative it may be nice to know.

05-06-2006, 10:00 PM
A little follow-up. If you want to pull that sensor and cap it off, a 3/8" bolt SAE Fine Thread is what it takes. I picked up a stainless steel bolt 1/2" long and a couple washers, then with the o-ring off the sensor it should seal up fine.

05-15-2006, 01:07 PM
I had the same problem with my SC recently and I did the quick fix and it works great Screws $1.67 from Kragen have to buy 3. Washers .09 from home depot. I also found out that ROCKAUTO.com sell the sensor. It is referred to as a Power Steering Pressure Switch made by Standard Motor Products for $58.79 Part# PSS18. I just wanted to pass this info along to help anybody with the leaky brake valve problem.

05-20-2006, 10:40 PM
Further followup. The bolt, washers + oring were not enough. Had brake fluid leaking at the track today.

Probably due to the hole in the fitting is designed for the tapered fit of the original sensor to help the o-ring seal. Gonna check the hardware store tomorrow for an alternative plug.