Rear drum brakes only engage in 4x4

[BeeTeeBee]

Hi guys, I have been having problems with my rear brakes on my 1999 Ranger 4.0. I just discovered that the only time they work is when I have my switch toggled to 4x4 high. If the truck isnt in 4x4 the wheels just roll and the front brakes do the work (not very well on snow covered surfaces). Any tips on where to start?

 

[swynx]

This happens from time to time on rbvs. There is a deal that controls the ABS that just quits. You can by pass it. Its on the frame rail the brake lines go thru it. Atleast on my year/Gen there is that thing.

Not sure how they could be related

 

[BronKitis]

Could this be because your front tires are locking up the entire drive train thus forcing the rear wheels to stop rather than the actual brakes engaging?

 

[BronKitis]

Sounds like swynx is more hip on the newer, fancier RBV's than myself! I'd check what he said first!

 

[BronKitis]

Could this be because your front tires are locking up the entire drive train thus forcing the rear wheels to stop rather than the actual brakes engaging?

 

[ab_slack]

Could this be because your front tires are locking up the entire drive train thus forcing the rear wheels to stop rather than the actual brakes engaging?

^^^ This is a very good point.

I can't think of any interaction between the braking system an 4WD other than this. And if this is the case, then it could be any issue with your rear brake line feed. Best way is to put rear tire up in the air and try using the brakes. That would need to be in 2WD since 4WD would prevent that if other tires on the ground. And if not look inspect the brakes and see if there is any movement.

I don't think the 99 have RABS (rear antilock only) system which would allow the front to lock while the rear won't lock (unless in 4WD when both would lock as stated above). If it were RABS then the system could be working normally. There would be a pulsation in the pedal.

I didn't think our 99 Ranger had antilock brakes cause I swore the fronts would lock but one time in the snow the brake pedal was pulsating. So not wondering if 99 came with RABS or memory is just faulty.

 

[LIMA BEAN]

Could this be because your front tires are locking up the entire drive train thus forcing the rear wheels to stop rather than the actual brakes engaging?

^This is sounding about right^.

 

[BeeTeeBee]

ould this be because your front tires are locking up the entire drive train thus forc

I have done a few things thus far:

Pulled fuse #14 (10 amp which means its 4wheel abs) in 2wd just the front brake worked but in 4WD the brakes worked fine with the exception of ABS.

I jacked the back up in 2WD and with the vehicle off the rear brakes worked, then with the truck on I put the vehicle in drive and let the wheels spin and tried braking and they did not work. Does this eliminate the possibility of what Bronkitis mentioned?

 

[fordkid64]

next I'd try to open up a bleeder on the wheel cul. And have some1 hit the brake pedal slow to see if your getting fluid back there. If not your problem may be in proportioning valve or abs. Of course, check master cylinder and make sure its full.

 

[Andy D]

Drum brakes? They need to adjusted.

 

[adsm08]

I would pull the drums off, make sure nothing has failed inside them, that they are adjusted, and that the adjusters are not frozen, and then start checking for issues with the hydraulics.

 

[RangerSVT]

Adjust the rear brakes...

SVT

 

[BRUTUS_T_HOG]

Sounds like perfectly functioning ABS to me. My rear wheels never lock up in ice because that's what it was designed to do.

Adjust the rear brakes and call it good if they work with the rear jacked up.

 

[BeeTeeBee]

Thanks for the things to check.

Just to clarify,jacked up the rear brakes did not work while the truck was running.


Something I should add, I drove the pickup home from work (15 miles) and once I reached town and got onto snow covered roads again the rear brakes worked in 2wd! Is there something that needs to build pressure or...? From that I can deduct that if the truck runs for awhile the brakes work.

Ill pull the drums apart tomorrow and adjust them.

 

[BRUTUS_T_HOG]

If you have the rear wheels off the ground, in gear and turning. The front wheels are not turning. The computer thinks you are in a panic stop and is preventing the rear brakes from locking and causing a spin.

If the rear brakes won't lock at 0MPH try pumping the brake pedal to see if adjustment is the problem.