Can’t bleed after disk swap

[Dantheman1540]

I put SN95 mustang disks on my ranger months ago and had trouble bleeding them then as I am having now. Basically I cannot get any fluid to come out of the bleed. If I crack the lines almost anywhere else in the system I get fluid, although it’s not a super strong jet when cracked and the pedal is pumped.

Right before I put these disks in my drums were working and would kick the ABS on when activated on dirt. Now the rears do absolutely nothing whatsoever, which includes the parking brake despite it being fully activated.

Anyone have a similar problem? I even bought new calipers today and I’m still having the same issue.

 

[Josh B]

Any chance those lines had some gunk in em?

 

[Dantheman1540]

I cleaned them with brake fluid before installing, the soft lines are all new stainless lines, and even now if I disconnect the line at the ABS modulator and shoot brake clean it jets right out the soft line that attaches to the caliper.

So either my ABS modulator died suddenly or does not push enough pressure to the rear. The master is failing to send enough pressure to the rear. Or the calipers are for some reason not working right.

However if I crack the line on the master which leads to the rear it squirts out a good bit of fluid making me believe that the master is okay. Although there’s no way to really quantify if the amount coming out is enough.

 

[RonD]

Front line on Master goes to the rear brakes

With foot off the brake pedal all lines are open from master to each wheel, so opening a bleeder should get fluid Gravity Bleeding from the Master's reservoir

ABS valve limits flow when activated, to prevent lock up, so are wide open when not activated


Take cap off the master just to make sure Vented Cap is not clogged
Open a front wheel caliper bleeder and see what kind of flow you get
No air can get in
Its just gravity, i.e. fluid running downhill, but should drip out pretty well

Then try rear, should be the same flow as front, master is the same height above caliper, lol

ABS valves can get crud in them, many replace them with an adjustable proportioning valve
Leave ABS valve plugged in so ABS light stays off, if you do this

 

[Dantheman1540]

So I have already tested to see if the bleeders leak any fluid when left open and they do not. When I pull the lines off the caliper they will leak a little initially but stop fairly quickly, meaning there is some sort of blockage in the ABS correct?

I do not want to lose rear abs so I can replace it with a new module if that is indeed the culprit.

 

[RobbieD]

Is this a 1994 Ranger? I thought that '94s had RABS only, not ABS on all four wheels (which Explorers do have). Mainly curious what antilock setup your truck has.

 

[Dantheman1540]

Is this a 1994 Ranger? I thought that '94s had RABS only, not ABS on all four wheels (which Explorers do have). Mainly curious what antilock setup your truck has.

Correct it’s a 1994 with rear abs only

 

[RobbieD]

Sorry, brain fart on my end. When you said checked flow to the rears from "ABS modulator" you're talking about the one on the frame.

 

[Dantheman1540]

Sorry, brain fart on my end. When you said checked flow to the rears from "ABS modulator" you're talking about the one on the frame.

Yep driver side, pretty crappy spot.

 

[Dantheman1540]

Come to think of it, yes when I disconnected the line after the ABS modulator and had someone press the pedal it would squirt a small amount. But when the pedal wasn’t pressed it didn’t really leak anymore with gravity. Leading further to thinking it’s the modulator

 

[Bgunner]

if you happen to have the items on hand you could try a bypass around the modulator and see if that makes a difference. This would tell you if the modulator is stuck closed or partially stuck.

 

[Snoranger]

Your RABS module is clogged/bad. You may have some luck pulling it, disassembling it, cleaning it, and reinstalling it… you may not.
My recommendation is to either replace the RABS module or install an adjustable proportioning valve in its place (and adjust it for your new brakes.)

 

[RonD]

RABS Valve rebuild here, with pictures: https://www.ranger-forums.com/gener...rabs-rear-abs-disassembly-ranger-98-a-170733/

Rebuilt run $150-$180

 

[Dantheman1540]

if you happen to have the items on hand you could try a bypass around the modulator and see if that makes a difference. This would tell you if the modulator is stuck closed or partially stuck.

That’s too much laying on my back with brake fluid dripping on me. I’m getting lazy as I age.

Your RABS module is clogged/bad. You may have some luck pulling it, disassembling it, cleaning it, and reinstalling it… you may not.
My recommendation is to either replace the RABS module or install an adjustable proportioning valve in its place (and adjust it for your new brakes.)

I’d really like it to work like factory so I’ll just pickup a new rebuilt one, should last 29 years like this one has. I find it so coincidental that it poohed the sheets exactly during my disk swap tho.

RABS Valve rebuild here, with pictures: https://www.ranger-forums.com/gener...rabs-rear-abs-disassembly-ranger-98-a-170733/

Rebuilt run $150-$180

New one will be here Friday! That rebuild is tempting but idk that it’s worth the hassle of possibly having to install and remove twice if I mess it up somehow.

 

[sgtsandman]

That’s too much laying on my back with brake fluid dripping on me. I’m getting lazy as I age.



I’d really like it to work like factory so I’ll just pickup a new rebuilt one, should last 29 years like this one has. I find it so coincidental that it poohed the sheets exactly during my disk swap tho.



New one will be here Friday! That rebuild is tempting but idk that it’s worth the hassle of possibly having to install and remove twice if I mess it up somehow.

You could rebuild it and keep it as a spare for a while. Then sell it later if it seems to be taking up too much space or is not needed.