Brake/ABS Light Illuminated

[cerberusiam]

James... I'm with you there! What I'm asking and not just you in particular, is with my ABS not working (not in the braking loop) I have way too much <b>bias</b> to the rear brakes! Yes, I can control it through my applied pressure, but I'm not achieving maximum braking efficiency.



I have no problem with bypassing the ABS controler, but it seems that most of you are doing this to gain braking bias to the rear? No? I seem to already have too much!



And I am refering to first gen braking... . "1992"

Thats part of the problem of bypasing the system, you loose the automatic bias. I am firmly convinced the only reason ABS was added to these trucks WAS to keep the rear tires from locking up under braking. It's a pain when it doesn't work right and even worse to trouble shoot, but, when it works correctly it is good.



What you need is a bias controler like the racers use to adjust between the front and rear and balance the the braking. These trucks simply don't have enough brake surface to lock the front under good traction and the rear is way too light with something to control the bias. Once you can adjust the balance you can set the rear up so it will brake hard but not slide the tires at the first stab. Takes some $$ and some time but it works pretty well once it is done.

 

[jimnance]

You lose cruise control if the ABS harness is disconnected????

 

[dpuckett]

No, you keep cruise even without ABS- Mom's 92 has been that way for 6 years.



With those of you fortunate enough to have good enough pressure to the rear WITH functioning ABS, I's say leave it. If you unhook the ABS and get too much rear bias, couldnt you back off your rear brakes a hair? Ok, the trucks with the somewhat functional ABS are probably also the ones with functioning rear adjusters. For most of us, "self adjusting" means crawling under there yourself and adjusting them.



-DP

 

[cerberusiam]

If you unhook the ABS and get too much rear bias, couldnt you back off your rear brakes a hair?

Yeah you can, but then you lose full braking because you don't get enough fluid to the rears before the fronts get tight. Makes for a weird feeling pedal. Without the ability to adjust the bias the stock settings are incorrect without the RWAL. Its a job to keep the rears adjusted when every thing is working correctly, now lets take a piece out an loosen one end a bit. I LIKE to work on my truck but not that MUCH.

 

[1stgen4evr]

"now lets take a piece out an loosen one end a bit. "



Sort of like daylight savings.



My trucks are duallys so I can stand on the brakes and not lock the rears. Also I carry some extra parts/weight in the bed along with the tongue weight which in my case is significant. So I don't have the rear lock up problem at all. But I would suggest that the problem is one of application (what you do with the truck).



If you only use the empty truck for transportation then the stock brakes from 89 models are adequate if they are in good working order. Then you add the dynamic of undetermined extra weight and the equation for setting the braking need goes out of control. The attempt at control is the ABS which theoreticall will cover the socker mom and the dump truck application. Good idea, it just doesn't work out all that well. What we have on the Dodges is a compromise starting with the needs of those socker moms and going to needs of near simi load range hauling.



If you have too much rear brake FOR THE WAY YOU USE YOUR TRUCK, install the smaller wheel cylinders on the rear and/or the narrow brake shoes of the 89 (and 90 I think).



There are options as to type of pads on the front that will also balance the stoping (bias) on your truck.



But the addition of a system that is always, sometimes, never and no way to tell which it will be (due to road dynamic) is simply not a good engineering choise.



And I repeat that ABS systems (working perfectly as designed) are known to have been the initiating cause of deaths in vehicles.



Now you can take all of the above and fifty cents and get a cup of coffee where they still sell cheap coffee.



In the USA, the choise is yours.



James

 

[HRDROKN]

There are options as to type of pads on the front that will also balance the stoping (bias) on your truck.

Does anyone now of a source for performance brake pads for our trucks?

Now you can take all of the above and fifty cents and get a cup of coffee where they still sell cheap coffee.

James

Now were talking! :-laf

 

[rvaughn801]

Slash and burn

Buy the $2. 00 worth of fittings and bypass the rear ABS. If you hate the feeling of solid brakes and miss the sinking feeling when the light turns red before you expected, you can always go back.



Should I have a future buyer (God forbid) of the truck sign something acknowledging the ABS has been removed?



I hate to imagine buying a Honda for the wife and someone had modded away stability control. :{

 

[BGore]

I have the same problem as HRDROKN with my 92. 195,000 miles and still have the ORIGINAL factory brake pads in the front, have worn out 3 sets of rear shoes. I've owned the truck since it was new, and have run the gamut of the ABS problems. But my problem was when they weren't working the rear would lock, especially on wet or icy pavement while there seemed to be NO braking from the front.



The ABS is working (as well as it works ) for now, but anytime anyone else drives it they tell me my brake pedal goes to the floor, which if course it doesn't, but feels like it when the the truck's not stopping. It has a persistant "mushy" feel, and no matter what I do (except complete removal of the ABS as described, haven't done that yet) I can't get rid of it.



So I'm not sure what's worse. For right now my solution is the keep weight in the back of the truck so I have SOME braking power.



-Ben

 

[1stgen4evr]

"have the same problem as HRDROKN ---seemed to be NO braking from the front"



Hummm. There must be a very different dynamic with this problem that I have never encountered. I have had fairly even wear on the front/rear components when the system (ABS) was working and extremely accelerated wear from the front when the rear was not as it should be. Also warped rotors on the front from over working them. And with the 195k miles you have on the front pads, clearly the fronts are not in the loop to any real extent.



But I can say that the 93 which I first eliminated the ABS from, always had a pedal that felt like it needed to be bleed and I could not make that go away. There is a tool described for bleeding the abs valve but no one has ever seen one in my circle, (including the Dodge dealers that I talked with). After taking the valve out of the loop, no problem bleeding.



When bleeding there must be balance between the systems at the component by the mastercylinder. (Don't know the name of the part, an aluminum rectangular part that has an electrical connection and four fluid lines attached) It is my understanding that this component is in the system to stop fluid from escaping in the event of a rupture at one of the axles. A faulty abs could have confused/corrupted that part and caused it to withold fluid from the front all this time. Could this item be your problem?



Anyone else have a thought or had a similar problem on this?



RichVaughn



"Buy the $2. 00 worth of fittings and bypass the rear ABS. If you hate the feeling of solid brakes and miss the sinking feeling when the light turns red before you expected, you can always go back.



AMEN BROTHER



Should I have a future buyer (God forbid) of the truck sign something acknowledging the ABS has been removed?



MIGHT NOT BE A BAD IDEA TO HAVE THAT DOCUMENTED.



I hate to imagine buying a Honda for the wife and someone had modded away stability control. "



WHAT IS A HONDA?



James

 

[BGore]

the component by the mastercylinder. (Don't know the name of the part, an aluminum rectangular part that has an electrical connection and four fluid lines attached)

I've heard a number of explanations about that part. I'm not really sure what to believe. I suppose I should look it up in my service manual that I recently got - as soon as I get it back from my neighbor (another 1st gen owner)



-Ben

 

[Sri Ram]

Interesting thread. I've also been confused about the brake operation on my truck, although they're a lot better than they were when I bought it! I seem to remember reading in my manual that the brake power is not divided evenly between front and back. If I remember correctly, it said that a certain psi goes to the rear before the front brakes are even involved. Could that be the function of the valve body by the Mcylinder James described? I'll try to find the info tonight…

 

[TKingsbury]

I've heard a number of explanations about that part. I'm not really sure what to believe. I suppose I should look it up in my service manual that I recently got - as soon as I get it back from my neighbor (another 1st gen owner)



-Ben

That valve should only be the safety switch. If there is a pressure differential (one side of the system fails), the shuttle inside is pushed over and turns on your dash light. There should be a valve in the system that delays pressure to the fronts, seems kinda stupid to me as a rear brake lock situation will cause your truck to try to swap ends. There should also be a proportioning valve which reduces the pressure to the rear so it doesn't lock up as easily. The abs' only function is to make the wheels that lock up start to turn again. That's why when it actuates it feels like you speed up, because it momentarily takes pressure away from the rears by opening the valve on the accumulator to make the tires regain traction. The answer to our problem would be a self adjusting proportioning valve like alot of Jap trucks have/had. It is linked to the rear axle housing so when the rear goes down you get more brakes and when it raises you get less brakes. Simple and effective. Although I don't know if anyone makes an aftermarket set-up like that or not.

Travis. .

 

[BGore]

a rear brake lock situation will cause your truck to try to swap ends.

That's exactly what happened to me - twice - in the middle of intersections.



I haven't been able to locate anything that looks like a proportioning valve. I would certainly like to get more brake in the front, so I'm open to suggestions.



My truck is about to go through a major overhaul hopefully this summer - get all body/rust issues fixed (anybody else have problems with cab rust above the windshield?), all the little stupid electrical and mechanical problems taken care of, interior fixed up and get the "seat sag" fixed or maybe a new seat, then (if I have the money after all that) maybe some little performance tweaks and accessories. I had to put a new exhaust on last year, so it's already got the 4". The guy I work with says it sounds GOOOD!



-Ben

 

[cerberusiam]

I haven't been able to locate anything that looks like a proportioning valve

That big silver thing under the Master cylinder is the proportioning valve. Its just not adjustable.



There are multiple manufacturers of adjustable proportioning valves. Google it, set back and read.

 

[mysteryman]

ABS woes, brakes and friction materials, first gen.

I as well as others have posted a lot on this subject in the past few months. .

Here is a brief over view... Bare in mind that any of the info or advice that you use from this site you use at your own risk ...



Your problem at hand most likely is that the ABS valve is stuck. .

You can spend a lot of time and money fixing the ABS system or you can remove it and be done with the problem altogether... The abs system in the early trucks never did work properly in the first place ! Read James posts above.



The chassis that is used on the 89 to 93 diesel trucks was not a new thing in 89 at all. It started in 1972 model year . . The brake drums, rotors backing plates ect ect were the same from 72 to 93 in the one ton trucks and most of the 3/4 ton trucks... . The early trucks never had abs brakes. They stopped just fine ! BUT you did have to know how to drive a truck. . And soccer moms did not use D300 dually's for picking up the kids everyday either...



A few other things to note on these brake systems is that there is no one today making the proper friction material any longer... These systems were designed to use ASBESTOS friction lining... . Most of the friction material being used on the rear shoes ( part #'s 357 and 358) is not much more than Elmer's glue and old shoe box. . Expect to lose 40% of your rear brake efficiency when you use these non asbestos shoes...

Metallic pads for the front have been around for a long time. ( # D86, 2wd)

Most will stop as well as the asbestos but you will be buying a lot of rotors. .

The semimetalic asbestos lining is still your best bet.



The pistons in the front calipers are made from an epoxy resign... They swell

and cause the brakes not to release fully with age... I recommend that everyone replace these pistons with steel pistons...



There is one company that currently makes a pretty good friction material out of carbon Kevlar... I had some pads and shoes relined with their friction material a few years back for a fleet... I could have some more made up. I would have to get shoe and pad cores . . There is also a min. order of 100 sets each. If anyone is interested I can make it happen. . I do not need any myself . I have half a container full of the asbestos that I bought for myself that should last me the rest of my lifetime



happy breaking

 

[Sri Ram]

Kind of moot at this point, but…Checked the manual. When working as designed the "proportioning valve," as we are calling it, holds off full braking pressure to the front brakes until 117psi is reached, and then applies full pressure to the fronts as well.



MM, does anyone make steel pistons for our trucks, or is that another custom part we have to order by the gross?

 

[BGore]

the "proportioning valve," as we are calling it, holds off full braking pressure to the front brakes until 117psi is reached

Hmmm. I wonder if mine isn't working right. If so it's been that way since it was new. When putting on an aftermarket valve, should you replace this "valve" entirely in conjunction with disabling ABS, etc?



My only concern about disabling ABS is our vehicle inspections here are getting more and more strict about modification of factory systems, especially those related to "safety", even though we all know the factory system isn't as safe as it should be.



I'm trying to gather all the info I need for these issues since I would like to take care of them all as part of the work this summer. Obviously the calipers are on the list, as are door hinges and the other items mentioned in my earlier post.



I've read on here some people have done a conversion on the rear to discs, but I haven't read a lot of feedback. How do these work, and how available are the parts?



Thanks for all your valuable info.



-Ben

 

[HRDROKN]

Your problem at hand most likely is that the ABS valve is stuck. .

Hmmm..... this just might be my problem also! So if the valve is stuck then theoretically I'm bypassing the function of ABS and therefore would have the same result as if I had done the slash and burn?



I think that I will eliminate the whole ABS rather than repairing (or trying too)... :-laf



I'm going to get into my front brakes this weekend... I'll look around to see whats offered as far as pad material goes and we'll just see what happens.



I will keep my old pads in case we get enough interested guys together for mysteryman to do his thing!

 

[1stgen4evr]

"I've read on here some people have done a conversion on the rear to discs, but I haven't read a lot of feedback. How do these work, and how available are the parts?"



I can't give any advise as to getting the setup but I have a Dana 80 rear that came with discs. The axle is from a burned 03 truck. I am sure they are adequate for all the stopping you might want and they have a park prake built into the disc portion which looks quite good. It would appear that the park stuff can be attached where the first gen park cables attach. I am thinking that I will use this on the crew project.



The 03 has hydroboost and there will be other things to solve and route but I think it will make a good upgrade.



James

 

[TKingsbury]

Kind of moot at this point, but…Checked the manual. When working as designed the "proportioning valve," as we are calling it, holds off full braking pressure to the front brakes until 117psi is reached, and then applies full pressure to the fronts as well.



MM, does anyone make steel pistons for our trucks, or is that another custom part we have to order by the gross?

The prop valve and hold-off (forget what chryco calls it) are two different things. They used to be seperate units, but may be combined into a multi-valve block. The proportioning valve reduces pressure to the rear brakes. The hold-off momentarily keeps the fronts from applying. 117psi in a brake system is nothing, unless you are trying to lightly touch the brakes while on ice instant end-swapper. The steel pistons by this day and age should be in any reman caliper you get, but check to be certain as I'm sure some do slip through.

Travis. .