How to rabs replacement or bypass with pix

YBCold · November 25, 2009

INTRO

Right so from what i have read and experienced the rabs module on the first gens tends to be unreliable. in my case it developed a leak sometime over the summer. since i dont really care for ABS i decided to remove my Rabs Module. heres some pix of my attempt. and some how to stuff.

This one is for a 91 model 2WD i have read here on the forum that some 93s and 94s have four way ABS systems im not sure. if anyone knows please post comment to clarify.

Here is a Video By Expert Village that is almost exactly what I did.

OTHER SYNONYMS for the RABS module include - HCU (Hydraulic Control Unit) RABS Valve and Proportioning Block heres a picture of it
TOOLS NEEDED
Ratchet wrench In my case i used 9/16s, 10 Metric for my fittings.

*i also had to use a 12 metric wrench and 3/8s for my new fittings. i dont think the change in fitting size should matter aslong as the line is same. and it is.

Wrenches of the same sizes

Flaring Tool. MAKE SURE IT IS A DOUBLE FLARING TOOL! the one at Harbor freight is for plumbing. double flare are built to be stronger and have the dyes to double flare. i got mine at CSK. for $25USD
There are pix you can find of how to make a good double flare. make sure you know what it looks like.

Flashlight

Pipe cutter or something to cut the lines with.

brake fluid

New Brake line

****YOU ARE RESPONSIBLE FOR YOUR WORK AND ANY OF THE MISTAKES ARE YOURS. NEITHER I (N)OR THE FORUM TAKE RESPONSIBILITIES FOR YOUR ACTIONS****

BEFORE ANYTHING DISCONNECT YOUR BATTERY! and always use common sense!

Step one 1- Recognize your problem i had a spongy break and my car would hemorage brake fluid on the floor of my parking lot.

Step 2. Remove Retaining Hardare. This a 10 Size nut in the Front Drivers Side Fender well area here is a far and close up pictucre. you might need some PB blaster and possibly remove the tire but not really necessary

Close up FAR

Step 3 remove lines from the HCU
for this i had to use a combination of pliers, hack saw and file to cut one off. the other one i was able to bend and just use plier / wire cutter. dont worry too much about damaging the lines. as long as you have enough slack to reconnect them.

Also obviously disconnect the harness from the HCU and cover it somehow for future use should you want to convert back to ABS.

once you have them removed the RABS module just comes out and you can use a ratchet to remove the fittings from it.

once i removed the HCU ,I tried at first to just loosen the fittings around the HCU with PB Blaster but they were so badly siezed i had to use my 3/8 breaker bar to get them off.

it also may become necessary to drop your fuel tank but i dont know how so i didnt but . however its likely that my brake lines will wear out early. the chasis will rub a hole into them so just be aware of that. it would be preferd to use the chasis clips.

Then Reflare the lines. Installation is reverse of removal. Bleed Brakes

TO BYPASS

I went down to the Autozone around the corner from my house to get a 1/4 union (it might be different in your Exploder.) also try to keep your original fittings. i could not find a replacement for the fitting around the Brake Master Cylinder which was stripped when the PO replace the HCU.

It was my intention to replace the entire rear line. but i could not remove the old line. it some how became snagged along the frame rail between the gas tank so i just cut the extra. i had to goto autozone and purchase a new line. it was easy to thread the new one while it was straight. however i could not clip it to the clips so in time it will get rubbed through by the frame.

Here is a picture of where the Rear line connects to the rear brakes.

it is located up near the rear driverside tire. dont confuse it with the one over the rear differential. that connects the rear brakes together.

HERE ARE SOME THREADS I FOUND USEFUL

http://www.explorerforum.com/forums//showthread.php?t=257833

http://www.explorerforum.com/forums//showthread.php?t=259307

http://www.explorerforum.com/forums/showthread.php?t=257831

http://www.explorerforum.com/forums/showthread.php?t=254700

http://www.explorerforum.com/forums//showthread.php?t=202283

THATS ALL I HAVE FOR NOW

ANY QUESTIONS OR SUGGESTIONS OF ANYKIND ARE APPRECIATED LET ME KNOW WHAT I COULD HAVE DONE DIFFERENT OR IF ANYONE HAS DONE THIS BEFORE.

btw if the pictures dont work or expire just PM me i have a backup and will repost as needed i plan on getting an elite membership some day when i can afford a debt card. EMAIL - brandon_eme@yahoo.com all lowercase

:salute:

:wavey:

stanlam · January 15, 2011

Thanks a million!!!!

I have a 1992 Ford Explorer XLT with 2WD. I was ready to dump this car because the brakes were driving me crazy. First the brakes were obviously weak and felt very soft. So the mechanic removed the wheels and my brakes were almost metal to metal. I paid to get new brakes in the back. The mechanic then tried to bleed the new brakes, but the line won't bleed. From there we guessed it was the master cylinder. That was replaced next and the problem was still there. Then I found your article and figured it had to be the rear ABS. However, I didn't want to pay another $150 for a car that is only worth about $500. I went to the store and bought the 1/4 inch coupling and now my car works again. Bypassing the ABS was very simple with your help.

Thanks!!!!!!!!!!

YBCold · January 16, 2011

no problem. i hear the aftermarket replacement RABS modules are crap-tacular. they rust from the inside out and if u get air trapped inside of them u need to have a special OBD scanner to sequence the valves and bleed it. some folks on here have those. but it would be hard to find

huntman58 · January 16, 2011

most 93 and all 94's do have 4 wheel ABS. just to let ya know.

stanlam · January 16, 2011

YBCold said:
no problem. i hear the aftermarket replacement RABS modules are crap-tacular. they rust from the inside out and if u get air trapped inside of them u need to have a special OBD scanner to sequence the valves and bleed it. some folks on here have those. but it would be hard to find

that's why I was so thankful that you wrote the instructions on bypassing the ABS.

thanks again.

spc4 · February 26, 2012

By-pass Rab short cut

YBCold said:
INTRO

Right so from what i have read and experienced the rabs module on the first gens tends to be unreliable. in my case it developed a leak sometime over the summer. since i dont really care for ABS i decided to remove my Rabs Module. heres some pix of my attempt. and some how to stuff.

This one is for a 91 model 2WD i have read here on the forum that some 93s and 94s have four way ABS systems im not sure. if anyone knows please post comment to clarify.

Here is a Video By Expert Village that is almost exactly what I did.

OTHER SYNONYMS for the RABS module include - HCU (Hydraulic Control Unit) RABS Valve and Proportioning Block heres a picture of it
TOOLS NEEDED
Ratchet wrench In my case i used 9/16s, 10 Metric for my fittings.

*i also had to use a 12 metric wrench and 3/8s for my new fittings. i dont think the change in fitting size should matter aslong as the line is same. and it is.

Wrenches of the same sizes

Flaring Tool. MAKE SURE IT IS A DOUBLE FLARING TOOL! the one at Harbor freight is for plumbing. double flare are built to be stronger and have the dyes to double flare. i got mine at CSK. for $25USD
There are pix you can find of how to make a good double flare. make sure you know what it looks like.

Flashlight

Pipe cutter or something to cut the lines with.

brake fluid

New Brake line

****YOU ARE RESPONSIBLE FOR YOUR WORK AND ANY OF THE MISTAKES ARE YOURS. NEITHER I (N)OR THE FORUM TAKE RESPONSIBILITIES FOR YOUR ACTIONS****

BEFORE ANYTHING DISCONNECT YOUR BATTERY! and always use common sense!

Step one 1- Recognize your problem i had a spongy break and my car would hemorage brake fluid on the floor of my parking lot.

Step 2. Remove Retaining Hardare. This a 10 Size nut in the Front Drivers Side Fender well area here is a far and close up pictucre. you might need some PB blaster and possibly remove the tire but not really necessary

Close up FAR

Step 3 remove lines from the HCU
for this i had to use a combination of pliers, hack saw and file to cut one off. the other one i was able to bend and just use plier / wire cutter. dont worry too much about damaging the lines. as long as you have enough slack to reconnect them.

Also obviously disconnect the harness from the HCU and cover it somehow for future use should you want to convert back to ABS.

once you have them removed the RABS module just comes out and you can use a ratchet to remove the fittings from it.

once i removed the HCU ,I tried at first to just loosen the fittings around the HCU with PB Blaster but they were so badly siezed i had to use my 3/8 breaker bar to get them off.

it also may become necessary to drop your fuel tank but i dont know how so i didnt but . however its likely that my brake lines will wear out early. the chasis will rub a hole into them so just be aware of that. it would be preferd to use the chasis clips.

Then Reflare the lines. Installation is reverse of removal. Bleed Brakes

TO BYPASS

I went down to the Autozone around the corner from my house to get a 1/4 union (it might be different in your Exploder.) also try to keep your original fittings. i could not find a replacement for the fitting around the Brake Master Cylinder which was stripped when the PO replace the HCU.

It was my intention to replace the entire rear line. but i could not remove the old line. it some how became snagged along the frame rail between the gas tank so i just cut the extra. i had to goto autozone and purchase a new line. it was easy to thread the new one while it was straight. however i could not clip it to the clips so in time it will get rubbed through by the frame.

Here is a picture of where the Rear line connects to the rear brakes.

it is located up near the rear driverside tire. dont confuse it with the one over the rear differential. that connects the rear brakes together.

HERE ARE SOME THREADS I FOUND USEFUL

http://www.explorerforum.com/forums//showthread.php?t=257833

http://www.explorerforum.com/forums//showthread.php?t=259307

http://www.explorerforum.com/forums/showthread.php?t=257831

http://www.explorerforum.com/forums/showthread.php?t=254700

http://www.explorerforum.com/forums//showthread.php?t=202283

THATS ALL I HAVE FOR NOW

ANY QUESTIONS OR SUGGESTIONS OF ANYKIND ARE APPRECIATED LET ME KNOW WHAT I COULD HAVE DONE DIFFERENT OR IF ANYONE HAS DONE THIS BEFORE. HATERS DO YOUR JOB!

btw if the pictures dont work or expire just PM me i have a backup and will repost as needed i plan on getting an elite membership some day when i can afford a debt card. EMAIL - caguama@hushmail.com all lowercase

:wavey:

Simplest way to by-pass Rab is to run new brake line from master cylinder to rear brake hose , (not the one on axel) you will need an adapter to attach line to master cylinder. the line you want to disconnect will be at the end of master cylinder facing you. saves alot of steps no need to remove rab unit on frame rail.

ski92 · January 5, 2013

spc4 said:
Simplest way to by-pass Rab is to run new brake line from master cylinder to rear brake hose , (not the one on axel) you will need an adapter to attach line to master cylinder. the line you want to disconnect will be at the end of master cylinder facing you. saves alot of steps no need to remove rab unit on frame rail.

-Has anyone tried this? What size adaptor do you nee between then the brake line and the MC?

-Is there a measurement for the one-peice brake line? What about 2 peice line w/ a union fitting at a more acessible area of the brake, the ABS unit area looks pretty tight.

-Assuming you can get the fittings off the abs unit is there enough play in the brake line to use a union fitting of connect the. I was also thinking of a small flexable Aeroquip line.

awood · January 5, 2013

Good post. I bypassed my 92 a few years ago. I didn't have a flaring tool, so I just bought a longer piece of tube and a couple of unions to attach it. I then coiled the tube so it would fit, making sure to keep clearance away from the exhaust.

Keep the old RABS module there in place with the connector plugged in. That way, the ABS light wont light up.

As these Explorers get older, it's good information like this post that keeps them running!

ski92 · January 5, 2013

awood said:
Good post. I bypassed my 92 a few years ago. I didn't have a flaring tool, so I just bought a longer piece of tube and a couple of unions to attach it. I then coiled the tube so it would fit, making sure to keep clearance away from the exhaust.

Keep the old RABS module there in place with the connector plugged in. That way, the ABS light wont light up.

As these Explorers get older, it's good information like this post that keeps them running!

awood: Great info. when you mentioned usuing a couple of unions, were these uesd as adaptors for the different fittings at:

(1) the master cylinder and
(2) the fitting on back of the RABS model

Do you remember the specs on the 2 adaptors.

Also, do you remember approx the size of tubing you used.

Thanks, Rick

ski92 · January 6, 2013

Opppps.... I ment to say do you remember the LENGTH of the tubing used.

awood · January 6, 2013

I left all the factory lines in place. As I recall, the line I bought was about 14 to 18 inches long. It was a pre-made line with flares and fittings already on it. I only inserted it in the gap where the RABS module would have been. To utilize the existing factory fittings on the truck, I had to by a couple of unions that would accept the male ends of both the existing truck fittings and the fittings of the new line.

I put a coil in the new line because I couldn't buy a line short enough to fill the gap where the RABS module was. Plus the coil gave me more flexibility when hooking everything up.

I wish I'd taken some pictures.

awood · January 6, 2013

Here's a picture from Google. Be careful when you coil it so you don't kink it!
http://images1.carpartsdiscount.com...9_brake_line_oem_113_611_724_b_113611724b.jpg

ski92 · January 7, 2013

awood said:
Here's a picture from Google. Be careful when you coil it so you don't kink it!
http://images1.carpartsdiscount.com...9_brake_line_oem_113_611_724_b_113611724b.jpg

awood: Thanks for the good info.

Do you remamber if any of the unions step-up or down from the tube or valve fitting? The fitting at the MC looks the same. Even getting to the fittings on the rabs is going to be a b...ch, the transfer case and drive shaft right in the way.

awood · January 7, 2013

Yep, it's tight in there. I believe the unions were the same size. No steps up or down. Sorry I don't remember more. It was too long ago. I may have gotten the brass unions at the hardware store - same thread.

R&T Babich · January 8, 2013

A single 1/4" union is all I used to connect the input line to the output line of the '92 RABS unit.
I can see where it will be difficult to install on a 4x4.

ski92 · January 29, 2013

R&T Babich said:
A single 1/4" union is all I used to connect the input line to the output line of the '92 RABS unit.
I can see where it will be difficult to install on a 4x4.

---Do you remember what flare wrench size is needed to losen the fittings at the abs unit?
-- which brake line at the MC goes to the rear (abs) unit
--When you say a 1/4 union, is it a standard NPT of are these special brake line fittings.

I'm trying to get all this info ahead of time because I have a tiny garage on an ally and it's hard to get up and go get things in the middle of a project

Thanks for all the help :salute:

ski92 · January 31, 2013

R&T Babich said:
A single 1/4" union is all I used to connect the input line to the output line of the '92 RABS unit.
I can see where it will be difficult to install on a 4x4.

R&T Babich; Hi, From your post I'm assuming you just remove the 2 lines from the RABS unit, removed the RABS and just bent the 2 lines close enough together to attach the union?

The front and rear fitting of my RABS unit came off in good shape and it seems once the RABS is removed there will be enough to bend the lines over to connect the 2. No replacing sections of brake line.

This is how you did it?

Thanks

PS: In both the Hanes and Factory manuels I have the say "remove the screw" to remove the RABS from the frame rail.

Where is this screw?????? Working on my back under the car I'm not seeing a screw.

YBCold · February 1, 2013

the nut is inside the the driver side front wheel well along the frame you will ned some extensions or get under there it s a 10mm nut holding the ABS valve in place.

Here is a picture of it

YBCold · February 1, 2013

the reason this turned out to be such a long article is that i kept messing up on my double flares that i ran out of line. and they didnt sell lengths of line long enough to go directly from the MC to the rear line behind the gas tank. also with each patch i also ran out of fitttings. IIRC its been a long time since i did this

ski92 · February 7, 2013

YBCold said:
the nut is inside the the driver side front wheel well along the frame you will ned some extensions or get under there it s a 10mm nut holding the ABS valve in place.

Here is a picture of it

DOOH.....should have looked on other side of frame rail.

Un-did the bolt and off came the abs.

Since I was able to get the ffittings of the abs in good shape, I just bent the 2 lines around till they were close enough to attach a 1/4" union. The fittings at the abs require a 3/8" flare wrench and mine came off w/o needing tons of pressure. The problem w/ the 4x4 pupmpin and drive shaft are in the way of getting a full size wrench in there finish undoing the fitting. I would strongly suggest cutting a 3/8 wrench in 1/2 or 2/3 to make it a lot easier to spin off (and back on) the fitting. I wouldn't cut the flare wrench, you may need all the leverage you can get to initially brake the fitting free.

Thanks All for the help :salute:

PS: the diy pressure brake bleeder worked great!!! It can also be used to bench bleed the MC. The only thing was I had to use lots of slicon between the cap an the gasket to get it air tight.

LINKs to build your own:

http://www.youtube.com/watch?v=Ng_trFj9gg0

http://www.youtube.com/watch?v=wITXtytPklo

You can get a $5 guage at Harbor Frieght

How to rabs replacement or bypass with pix

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