Brakes

[d.h.]

I posted about lack of rear brakes awhile back and it was suggested that my prop valve was a possible cause to my dilema.Well I raplaced and no noticable differance.I thought that was it as well.The proportioning valve bolted directly to rwal device(Ithink).Has anyone had a problem with this.I don,t like the feel of brake pedal to spongy.I have dealt with many brake issues over the years and this one has me stumped.The brakes are bled proper,and while puming pedal you could hear rear brakes moving with the pedal pressure. The adjustmant of rears is spot on but still grabbing on fronts.The master cyl is another suspect but normally when they bypass you can feel the brake pedal depress with bleedown.I,m going to replace rubber lines at rear just incase the are callapsing,though I don,t think they are as when I bled rears there was no lack of pressure.I,m open to any comments or ideas at this point.Thanks

[Robyn]

I have a 94 thats doing the same thing.
I am starting to suspect the ABS system.

Good luck

Robyn

[JohnC]

I don't know about this first hand, but I thought I read somewhere that to properly bleed the anti-lock brakes, once air got in, you needed to do something with the Tech II.

[d.h.]

That would explain a lot if you needed something special to bleed brakes,as pedal doesn,t feel right when bleeding them.The brake pedal seems to take way to long to come up to pressure .I,ve never experienced a problem before with bleeding,I don,t know if rwal has a impact on the whole bleeding thing.I,ts been quite a problem as I,ve had a few mechanics and the dealer look into this problem with no results.

[d.h.]

Sorry didn,t notice drivtrain section.So does anyone know if their is some special trick to bleeding brakes on my 98?

[d.h.]

I take it by lack of response the brake bleeding is the same as I,ve always done. What about the anti-lock device mounted on driver fender well? Everything else has been replaced now and this is all thats left exept master cyl.Is there a test one can do to check operation of this?

Thanks

[JohnC]

I don't know this for sure, but my understanding is that you can bleed the brakes normally as long as no air gets into the antilock unit. Once air gets in there it can get trapped and you need the tech 2 to exercise the antilock function and expell the air. I could be completely wrong, or it could be information that only applies to certain years. Information worth every penny you paid...

[d.h.]

John, The brakes were bled without air getting into rwal unit as I just replaced calipers and pads (3rd set this year). I replaced prop valve this time as it was thought this could be problem.The prop valve bolted directly to the rwal unit so air did get in.The brakes were harder to bleed I suspect mainly because I had to remove lines to master cyl.
It took a long time to get pressure back to pedal this time as apposed to just replacing caliper and bleeing.I cracked lines on master cyl side pf prop vale to get air out,then bled all four corners as usual.There was absolutly no differance with brake preformance.
The other day we were leaving a parking lot and stopped at intersection and I felt for first time in 2 years rear brakes apply.It lasted 2 applications and now back to normal
This is why I ,am suspect of rwal unit as its all thats really left.I know this is probably a thousand dollar unit,but I want to tow my fifth wheel again and fronts are just not cutting it . I have a set of slotted discs to go on front in the hopes that I will get rear working again.I will wait until then though.Sorry for being long winded but this is the only issue Ive not been able to resolve with this truck.
Thanks

[a5150nut]

This is why I ,am suspect of rwal unit as its all thats really left.I know this is probably a thousand dollar unit,but I want to tow my fifth wheel again and fronts are just not cutting it .

d h, I just looked a Napa online. Couldn't find for your 98 but did find 94. You wern't far off on you rguess.

Computer Module remanf. $119.00 core $30.00

ABS Hydralice Syst. remanf. $654.00 core $250.00 :eek:

[d.h.]

I don't know this for sure, but my understanding is that you can bleed the brakes normally as long as no air gets into the antilock unit. Once air gets in there it can get trapped and you need the tech 2 to exercise the antilock function and expell the air. I could be completely wrong, or it could be information that only applies to certain years. Information worth every penny you paid...


John,this is what was up with my brakes.I,ts taken three years,10 shops and a lot of brake parts to find this out.I went with the mechanic for a road trip before they touched it he noticed soft pedal right away.The pedal did become a little softer after I replaced prop valve.He said even removing a caliper can cause air to get to rwal unit.I wouldn,t have thought this,but pedal is right up now with a solid feel.The rotors are shot as I knew,but wanted to resolve rears not working before I replaced front again.Bought a pair of slotted rotors for front as they are supposed to disapate heat better.The mechanic said if I do brake repairs in future and break a line open to drop by after and he will hook scanner to remove any air.Hope this helps anyone with a similar problem

[Shikaroka]

I wonder if Carcode can do this?
Will it do ABS stuff, or just engine?

[BradL07]

I am having some brake issues - soft pedal and excessive pedal travel - on my '07 Classic LBZ.

From the day I drove the truck off the lot, the brake pedal had way too much travel, way too soft, particularly compared to my '01 LB7.

I took the truck to the dealer 1 week later, told them to please bleed the brakes, as I suspected that this '07 Classic had been sitting for 6 months, and had somehow gotten air in the lines. Of course they told me everything was normal and not to complain.

I of course refused that non-solution for my problem and made a second trip on which the dealer did bleed the brakes, and they were very firm after that - for about a week. Another trip to a different dealer resulted in a "normal" diagnosis.

The brakes still feel soft to me, and it really bugs me to be able to push the brake pedal all the way to the floor when stopped.

Reviewing the posts above, how do I explain to the dealer what/why/how the ABS may have air in it and need to be bled via Tech II if it's not showing any codes?

[Mikeandwendy74]

Hate to say this because you probably did it correctly, but sometimes people miss this simple important step.....when bleeding brakes on these trucks always start passenger rear, driver rear, passenger front, driver front.You probably know this already buy ya neva neva know :)

[BradL07]

Point well taken on bleeding the brakes in the correct order - I didn't bleed the brakes, the dealer did. To verify, I will bleed myself and see if I still lose pressure/pedal feel after I "know" they've been bled correctly. It's just aggravating to me to have "sloppy" brake pedal on my '07 LBZ versus the tight pedal I had on my '01 LB7.