RWAL valve elimination '92

[Baron]

Has anyone just plain eliminated the anti lock valve on the rear passenger side frame??? That combined with the elimination of the black box behind the glove box and I have regular old brakes huh???

I still have mushy brakes after installing another master cylinder today. I mean like just about to the floor with stepping on the brake pedal hard. The ONLY place for mush to exist here is in the RWAL valve... ... right??? (except for a bad MC of course)

Has anyone ever put some kind of female plug on the incoming line to the antilock valve and in effect eliminated it ..... as a test???baron

 

[hdm48]

Jeller, what I did was I took the unit apart and made a plug to replace the spring in the accumulator (in the abs unit) and now I have very good brakes. In effect this is the same as removing it without dealing with the wiring.



-dave-

 

[BushWakr - RIP]

Maybe someone can clear this up for me but..... I can understand a malfunction in ABS, I can also understand the ABS not working but just why would the peddle go all the way to the floor???

There must be another issue here for that to happen. . ??

Surely you must have... no fluid, a fluid leak, pressure bypassing a shutoff valve, air in fluid or something else similar... No??





bob.

 

[BushWakr - RIP]

Ok, I made myself go look in "THE BOOK" tadaaa...



This sounds like something worth considering...



"... If a low pedal is experienced, pump the pedal several times. If the pedal comes back up, worn lining and worn rotors or drums are the likely causes.

A decrease in fluid level in the master cylinder reservoirs may only be the result of normal lining wear. Fluid level can be expected to decrease in proportion to wear..... "



I think if you have "topped up" the reservoir then you will not likely see exceptionally low fluid levels due to wear.



What's the condition of shoes/pads, rotors/drums???



bob.

 

[Baron]

Well the rotors are NEW with new pads... ..... the rear drums are virtually new with new pads. Mushy brake pedal. If it is a closed system and has been bled until NO air comes out it seems the only place to take the pressure is now the accumulator valve... antilock valve??

The levels in the master cyl are good... .

hdm... ... I am interested in your response as well. Sounds like you effectively stopped the accumulation resevoir with a plug. . what kind of "plug" did you install?? Did you have the mushy breaks prior to doing this? And did it solve your problem???? baron

 

[ETOBICOKE]

Brakes

Two more things you may want to have a look at, the rear brake adjustment and the way you are bleeding the brakes. Generaly these trucks need to have the rear drum brakes adjusted manualy, the self adjusting mechanism does not work very well. If the pads are new adjust so that there is a very slight drag. You will get a very low pedal if the rear brakes are slack and not be able to bleed them properly. There is a specific proceedure to follow when beeding the brakes. I had been told by a mechanic friend a few years back that it should be followed carefully otherwise it's impossible to get all the air out. Have a look at the service manual section 5 pages 8 and 9. If you don't have a service manual PM me.



Neil

 

[Baron]

thanks for that ... . I will ck those pages to see if we have been doing it correctly... ... the rears are adjusted baron

 

[DPKetchum]

Does the pedal get better if park brake pushed down some?Also as well as bleeding properly,bleed again after 12 to 24 hours for any air that reforms in lines. If pedal good after park brake depressed some look at rear adjust etc.

 

[paccool]

FWIW

When my brake booster took a dump the pedal was mushy and went down quite a ways. I suggest you check this just to be sure its not causing the problem you are describing. There is a procedure in the book that says to turn the engine off and apply the brakes. You should get good brake assist when you apply them 3 times. I didn't need to do this cause the damned thing went to the floor at the first try!



I can't remember the exact sequence but I checked the vacume at the cruise control unit on the fender and it was a little low. Pulled the adaptor out of the booster and plugged it, the vacume came up. I replaced the booster and the problem was fixed. Had firm brakes after that.