I believe I need to change my ABS Control Valve in my 97 f-250. From everything I have read I believe I have found what is causing my brake issues. My question is how do I go about changing one? I have done the usual stuff, pads, shoes, rotors, drums and bled the lines but this is new territory for me. Is there anything I should be aware of or certain steps to follow while changing it? Will I need to to re-bleed the brakes after the install? Any help is appreciated

 

soak the bolts/fitting with a penetrating oil more than a few time.
These are usually very rusty.

Removal

Disconnect the inlet and outlet brake lines from the RABS valve. Cap the lines.

Disconnect the wiring harness to the RABS valve.

Remove the three nuts retaining the RABS valve to the frame rail and remove the RABS valve.

Installation

Position the RABS valve on the frame rail. Install the three nuts and tighten to 17-23 Nm (12-17 lb-ft).

Connect the RABS valve wiring harness connector.

CAUTION: Do not overtighten the fittings.

Connect the brake lines to the RABS valve and tighten as follows:
1/2-20 threaded fittings use 14-23 Nm (10-17 lb-ft)
7/16-24 threaded fittings use 14-20 Nm (10-15 lb-ft)

Bleed the brake system as described in Section 06-06.

It is not necessary to energize the valve electrically to bleed the rear wheel cylinders

 

Although I've never had to change one it is pretty straight forward.

Way to slow!

 

What is wrong with it? If your brakes work then the valve is fine. If the abs light goes out after it starts then it is fine. It self tests and cycles the valve every time you start it.

 

I hate my phone spell checker.

 

In complement of the diagrams from Cuda (rep sent), here is a pic in place and the bleeder (arrow). And yes, I also ask what is wrong with it?

 

Thanks for the quick replies. Sorry I didn't respond sooner, I have been out of town. I think this is my problem because my brake pedal almost seems to bottom out and it takes a lot of pressure to get it to stop. The booster and master cylinder are fairly new as well the the pads and shoes. I cannot find any leaks in the lines or the wheel cylinders. I have tried to adjust the shoes like Ford says in the manual with no luck. I have also bled the brakes again for the second time. The brake light comes on every now and then but not every time I brake. What else can it be? I hear that these are a fairly common failer on these trucks.

 

Also when bleeding the system when do I bleed the new ABS valve? I have always started with the wheel farthest away from the master cylinder and moved in from there. Where does bleeding the valve come in?

 

Farthest to nearest. Passenger rear driver rear RABS passenger front driver front. The reverse if you go closest to farthest. It's key not to pump the pedal. Just put pressure on the pedal then bleed. Repeat until complete. Personally closest to furthest has worked well.

 

Did you already buy a new valve? You do have to bleed it if you're going to replace it but I really doubt that is it. With a low pedal you either have a bad booster vacuum pump, or master cylinder or a problem with the rear brakes. There is absolutely nothing in the abs valve that can cause a low pedal. Well, I take that back. It's possible but very very rare on Fords in my experience. If your fluid was super nasty when you bled it then I might suspect it but I'd still check everything else first.

To prove that the abs valve is not the problem, get someone to stand on the brake while you go open a rear bleeder. If fluid squirts pretty hard then the abs valve is probably not blocking it. As long as your master cylinder is working that is. It is very unlikely anyway. I know on a GM rear wheel system from back then they did go bad a lot but the accumulator didn't have enough room in it to let the pedal go all the way to the floor. Halfway maybe was it. I would guess Fords would be about the same. Also one big thing I noticed on GM rear wheel abs was you'd be going along at highway speed, start on the brakes and it would slow down but not as hard as normal then it would come on hard like normal. That is from taking up the slack in the accumulator.

There is a LOT that the Ford manual and every other manual leave out about rear drum brakes.
For Low pedal and hard to stop you should start with testing the vacuum pump. When the brake booster loses vacuum it goes to the floor on the old style Thick booster that we have. Obviously it's hard to stop too. With the engine running Pull the vac hose off the brake booster and stick your finger over it and see if it's sucking good. I'd reccomend putting a gauge on it too. You can use just a cheap vacuum gauge from the parts store. Let us know what you find ok.

You need to check for missing rubber caps, cracked hoses and disconnected hoses on that vacuum block on the left inner fender too. I've found the problem wrong there lots of times when it was a vacuum problem.

Oh and as far as the abs valve being a fairly common failure. Only by shops that don't have a clue what they are doing and happy homeowner mechanics that don't either. Seriously. I can't remember ever replacing one yet except one that was fried electrically from a flood. You would have to have some really really nasty fluid to make it stick on a Ford.

Your red brake light comes on, one reason anyway, for low vacuum like I was getting at.
An ABS problem, in the valve or the module, ALWAYS turns on the amber ABS light.

 

Yes, this recently happened to me. The pedal goes way down and you have to stand on it to get any effect. I had my goose-neck trailer with a 6 ton excavator on it at the time. Fortunately, I was going very slow and able to stop with the trailer brakes. It was the vacuum pump. They will go away without much warning.

I am having a problem with my ABS as well. The ABS light will stay on on the dash. The fuse is good. When it first started, the ABS light would cycle on and off occasionally. Now is stays on all the time. When I apply the brakes, it would act like the ABS was trying to keep the wheels from locking up, pulsing while coming to a stop, very annoying, like the rotors need turning. I removed the fuse and this stopped. I've also noticed my brake fluid dropping in the master reservoir, but cannot find any leak anywhere. No codes are coming up for this problem.

Charlie, I may need that control valve if yours turns out to be the vacuum pump. ??

 

Did the brake fluid start disappearing before or after the vacuum pump went bad. I'd almost bet it's getting sucked out the rear seal of the master cylinder. That could have trashed your pump and the booster will be right behind it. Pull the drums first and make sure it's not going out there. Then you can loosen the master and see if it's wet in the back of it.

It sounds like your abs module is going bad but you need to see what code you're getting first. The module tells the abs valve to pulse and the only two reasons for it to do that are it's sensing a lockup or the module is going bad. It's behind the glovebox. You can check the wire connector to it and also check the harness where it goes along the dash frame at the lower part of where the glove box goes. There are two screws there that I've seen several times cut into the abs wiring and cause problems.
Oh you need to check for codes while the abs light is on but before you shut it off. If nothing then really look hard at the wiring before condemning the module.

 

Disappearing before the vacuum pump went bad. Thanks, I'll loosen the master and take a look behind it.

I'll also check the ABS as you suggested.

 

Last summer my vacuum pump went out for the same reason. Brake fluid is hard on the guts of those things. It's been almost 9 months and I still haven't replaced the booster. It's getting done tomorrow. I haven't had very good power brakes since that happened.

 

I pulled my master loose and there is no fluid behind it that I cane see. I had my rear drums off in the last week and they're fine. I'm going to follow each and every line now and see is I can't pin it down, just need to make the time.